highly competitive market. Distribution on the valve market are based mainly on the construction project, the largest user of the valve is the petrochemical industry, power sector, metallurgy sector, the chemical industry and urban construction departments. The main application of the petrochemical industry API standard valve, the cut-off valve and check valve; the electricity sector with the main power plant using high temperature pressure valve, the cut-off valve, check valve and safety valve and water supply and drainage part of the low pressure valve butterfly valve, gate valve; the chemical industry mainly uses stainless steel valve, stop valve, check valve; metallurgical industry mainly uses low-voltage large-diameter butterfly valve, oxygen and oxygen valve ball valve; valve ball valve gate valve check valve globe valve butterfly valve
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Thursday, September 30, 2010
To share practical techniques to deal with common faults valve 60 Law
In the industrial automation instruments, the regulating valve is a heavy, combined with simple structure, attention is often not. However, it is in the process pipeline, the working conditions of the complex, if there are problems, we also hand busy busy feet. Because of its bulky, difficult to identify the problem, often thankless, but also put into operation system, the system completely, adjust the quality and environmental pollution.
First, raise the life expectancy method (8 methods)
1) to extend the life of the work of opening the Law
Regulating valve so that the beginning as far as possible on the maximum aperture, such as 90%. In this way, cavitation, erosion and other damage occurred in the head on the spool. With the valve core damage, increased traffic flow, the corresponding valve clearance a little longer, so continue to disrupt, and gradually shut down, so take full advantage of all of the spool until the spool and the sealing surface root damage, can not be used so far. At the same time, the work of opening big savings gap, and erosion weakened the very beginning than the valve opening in the middle and the small opening on the work life of 1 to 5 times more. Such as a chemical plant using this method, the service life of valve-fold increase of 2.
2) reduce the increase of the work of opening S and increased life expectancy method
Reduce S, that is, in addition to increasing the system valve outside losses to the distribution of the valve to reduce the pressure drop, in order to ensure flow through the valve, will inevitably increase the valve opening at the same time, reducing the valve on the pressure drop, so that cavitation, erosion is also reduced. Specific measures are as follows: after the valve pressure drop for plate cutting consumption; the closure of the manual control valves in series on the road to a more ideal valve opening until the work. The beginning of a major election in a small valve opening work, the use of this method is very simple, convenient and effective.
3) work to narrow the aperture diameter increases and increased life expectancy method
Through the valve to reduce the diameter to increase the opening work, the specific ways: ① replace a file of small-caliber valve, such as DN32 replaced DN25; ② body does not change, the replacement of small diameter spool valve seat Block. Such as a chemical plant overhaul will be replaced by cutting dgl0 items dg8, life expectancy increase by 1 percent.
4) damage to the location of the transfer method to improve the life of serious damage to the local transfer to a secondary position, to protect the valve core and valve seat sealing surface of the cutting surface.
5) growth in savings and increased life expectancy Law channel
Expenditure growth is the simplest channel thickening seat, so that the valve seat hole growth, the expenditure of the formation of a longer passage. On the one hand, closed-type savings can flow after a sudden
The expansion of a delay in the transfer of damage from the location of the sealing surface away from the role; On the other hand, an increase of cutting resistance, the pressure reduces the recovery, so that reduced cavitation. Some are designed to seat stepped hole, wave-like, that is, to increase the resistance and weaken cavitation. This method of introducing high-pressure valve device and the old valve will often be used to improve, but also very effective.
6) changes in flow and increased life expectancy method
Flow toward the opening direction of open-type flow, cavitation, erosion a major role in the sealing surface, so that the roots spool and spool valve seat sealing surface damage quickly; flow towards the closure of the direction of closed-type flow, cavitation, erosion role in reducing expenditure, the valve seat sealing surface below the protection of the sealing surface and the valve core roots, the prolongation of life. There were no open-type use flow valve, when the issue of prolonging life is more prominent, simply change the flow of life can be extended 1 to 2 times. 7) to use special materials to increase life expectancy method
For the anti-cavitation (damage to the shape of small points, such as honeycomb) and washed (streamline the minor groove), would be able to cavitation and erosion-resistant special materials to create expenditure items. This special material 6YC-1, A4 steel, Stellite Levin, carbide, etc.. For anti-corrosion can be switching to a more corrosion-resistant and have a certain mechanical properties, physical properties of materials. This material is divided into non-metallic materials (such as rubber, PTFE, ceramics, etc.) and metal material (such as Monel, Hastelloy, etc.) two types.
8) to change the valve structure to improve life expectancy method
Taken to change the structure or the selection of valves with longer life expectancy of the valve means to achieve the purpose of life, such as the choice of multi-level-type valve, anti-cavitation valve, valve, such as corrosion resistance. Second, often stuck valve or blockage of the block (card) method (6 methods)
1) cleaning method
Pipe welding in the slag, rust, and other waste products to reduce expenditures, the mouth-oriented site, the balance under the valve cover or plug the hole caused so stuck spool surface, surface-oriented and have a scratch injury, have a sealed surface indentation and so on. This often happens in the new system put into operation and put into operation after the initial overhaul. This is the most common fault. In such cases, the washing must be disposed of opening, with the exception of掉渣objects, such as the sealing surface should be abrasive damage; At the same time will open at the end of Sierra Leone in order to flush into the hole from the balance valve cover under the Java objects, and pipeline for washing. Put into operation before the full-regulating valve so that, for some time before the mobile medium into normal operation.
2) external erosion method
Easy to some precipitation, the medium containing solid particles in the ordinary valve adjustment often to reduce expenditures, the mouth of Service-oriented plug, valve cover at the end of the next external Cypriot Department scouring gas and steam. When the valves have a plug or jammed, the open external valve of the gas or steam can be fixed in the case of valve flushing the work completed so that the normal operation of valve.
3) the installation of pipe filter method
The regulation of small-caliber valve, especially the ultra-small flow control valve, the savings gap special small, medium there can be a little bit of Java objects. In such a case to plug the best pipeline in the valve is installed on a pre-filter, so as to ensure the smooth passage of media. With the use of locator control valve, locator is not working correctly, the gas inlets cutting is the most common fault. Therefore, the work zone locator, it is important to handle the gas source, is commonly used in the locator pipeline before the gas relief valve is installed on the air filter
ball valve Trunnion Mounted Ball Valve Floating Ball Valve Top Entry Ball Valve Three way ball valve V Type Ball Valve
We can offer more Knife Gate Valve Information.If you need us according your spcification to produce the Knife Gate Valve .
Need, please e-mail to valve401@gmail.com
First, raise the life expectancy method (8 methods)
1) to extend the life of the work of opening the Law
Regulating valve so that the beginning as far as possible on the maximum aperture, such as 90%. In this way, cavitation, erosion and other damage occurred in the head on the spool. With the valve core damage, increased traffic flow, the corresponding valve clearance a little longer, so continue to disrupt, and gradually shut down, so take full advantage of all of the spool until the spool and the sealing surface root damage, can not be used so far. At the same time, the work of opening big savings gap, and erosion weakened the very beginning than the valve opening in the middle and the small opening on the work life of 1 to 5 times more. Such as a chemical plant using this method, the service life of valve-fold increase of 2.
2) reduce the increase of the work of opening S and increased life expectancy method
Reduce S, that is, in addition to increasing the system valve outside losses to the distribution of the valve to reduce the pressure drop, in order to ensure flow through the valve, will inevitably increase the valve opening at the same time, reducing the valve on the pressure drop, so that cavitation, erosion is also reduced. Specific measures are as follows: after the valve pressure drop for plate cutting consumption; the closure of the manual control valves in series on the road to a more ideal valve opening until the work. The beginning of a major election in a small valve opening work, the use of this method is very simple, convenient and effective.
3) work to narrow the aperture diameter increases and increased life expectancy method
Through the valve to reduce the diameter to increase the opening work, the specific ways: ① replace a file of small-caliber valve, such as DN32 replaced DN25; ② body does not change, the replacement of small diameter spool valve seat Block. Such as a chemical plant overhaul will be replaced by cutting dgl0 items dg8, life expectancy increase by 1 percent.
4) damage to the location of the transfer method to improve the life of serious damage to the local transfer to a secondary position, to protect the valve core and valve seat sealing surface of the cutting surface.
5) growth in savings and increased life expectancy Law channel
Expenditure growth is the simplest channel thickening seat, so that the valve seat hole growth, the expenditure of the formation of a longer passage. On the one hand, closed-type savings can flow after a sudden
The expansion of a delay in the transfer of damage from the location of the sealing surface away from the role; On the other hand, an increase of cutting resistance, the pressure reduces the recovery, so that reduced cavitation. Some are designed to seat stepped hole, wave-like, that is, to increase the resistance and weaken cavitation. This method of introducing high-pressure valve device and the old valve will often be used to improve, but also very effective.
6) changes in flow and increased life expectancy method
Flow toward the opening direction of open-type flow, cavitation, erosion a major role in the sealing surface, so that the roots spool and spool valve seat sealing surface damage quickly; flow towards the closure of the direction of closed-type flow, cavitation, erosion role in reducing expenditure, the valve seat sealing surface below the protection of the sealing surface and the valve core roots, the prolongation of life. There were no open-type use flow valve, when the issue of prolonging life is more prominent, simply change the flow of life can be extended 1 to 2 times. 7) to use special materials to increase life expectancy method
For the anti-cavitation (damage to the shape of small points, such as honeycomb) and washed (streamline the minor groove), would be able to cavitation and erosion-resistant special materials to create expenditure items. This special material 6YC-1, A4 steel, Stellite Levin, carbide, etc.. For anti-corrosion can be switching to a more corrosion-resistant and have a certain mechanical properties, physical properties of materials. This material is divided into non-metallic materials (such as rubber, PTFE, ceramics, etc.) and metal material (such as Monel, Hastelloy, etc.) two types.
8) to change the valve structure to improve life expectancy method
Taken to change the structure or the selection of valves with longer life expectancy of the valve means to achieve the purpose of life, such as the choice of multi-level-type valve, anti-cavitation valve, valve, such as corrosion resistance. Second, often stuck valve or blockage of the block (card) method (6 methods)
1) cleaning method
Pipe welding in the slag, rust, and other waste products to reduce expenditures, the mouth-oriented site, the balance under the valve cover or plug the hole caused so stuck spool surface, surface-oriented and have a scratch injury, have a sealed surface indentation and so on. This often happens in the new system put into operation and put into operation after the initial overhaul. This is the most common fault. In such cases, the washing must be disposed of opening, with the exception of掉渣objects, such as the sealing surface should be abrasive damage; At the same time will open at the end of Sierra Leone in order to flush into the hole from the balance valve cover under the Java objects, and pipeline for washing. Put into operation before the full-regulating valve so that, for some time before the mobile medium into normal operation.
2) external erosion method
Easy to some precipitation, the medium containing solid particles in the ordinary valve adjustment often to reduce expenditures, the mouth of Service-oriented plug, valve cover at the end of the next external Cypriot Department scouring gas and steam. When the valves have a plug or jammed, the open external valve of the gas or steam can be fixed in the case of valve flushing the work completed so that the normal operation of valve.
3) the installation of pipe filter method
The regulation of small-caliber valve, especially the ultra-small flow control valve, the savings gap special small, medium there can be a little bit of Java objects. In such a case to plug the best pipeline in the valve is installed on a pre-filter, so as to ensure the smooth passage of media. With the use of locator control valve, locator is not working correctly, the gas inlets cutting is the most common fault. Therefore, the work zone locator, it is important to handle the gas source, is commonly used in the locator pipeline before the gas relief valve is installed on the air filter
ball valve Trunnion Mounted Ball Valve Floating Ball Valve Top Entry Ball Valve Three way ball valve V Type Ball Valve
We can offer more Knife Gate Valve Information.If you need us according your spcification to produce the Knife Gate Valve .
Need, please e-mail to valve401@gmail.com
Repair of high pressure control valve program
Zhanjiang Power Plant No. 2 to No. 1 high-pressure steam turbine control valve to open failure, seriously affect the unit safe and stable operation. To the disintegration of the valve, it was discovered high-pressure Control Valve seat sink 10 mm, leading to valve plate from the guide groove-oriented convex shoulder, unable to conduct the normal adjustment process steam. In view of Temporary repair crew a short time, the valve seat sink on-site hard to recover, decided to adopt the surfacing treatment, increase the orientation convex shoulder height, to reach the main steam pressure regulating valve to restore the original functional.
A high-pressure main steam valve repair program
1.1 The valve disc-oriented working mechanism of convex shoulder
Unit No. 2 for the manufacture of Dongfang Steam Turbine Works (N300-16.7/537/537-3 type) steam turbine, and its main steam pressure regulating valve is a main steam valves and 2 control valve composed of high-pressure regulating valve is used to regulate the amount of high-pressure steam into the cylinder. Unit run-time, the oil motive for mechanical lifting equipment, so that valve disc oriented convex shoulders move up and down along the guide slot, the control valve disc opening. Unit run-time, high-temperature steam control valve 16.7 MPa, 537 ℃, oriented primarily to withstand thermal stress convex shoulders and some weeks to shear stress.
No. 1 high-pressure regulating valve with the valve disc and valve seat diameter of 170 mm, the valve plate structure shown in Figure 1, oriented convex shoulder size 55 mm × 30 mm × 10 mm (H × W × thickness). Valve disc material used 20Cr3MoWVA alloy steel, in order to improve the resistance to cavitation valve disc performance, its surface temperature nitriding treatment conducted.
1.2 surfacing materials and welding equipment selection
According to the working conditions of control valve, the valve plate oriented convex shoulder it is necessary to ensure that there are sufficient high-temperature strength, but also to meet some wear. In view of crew repairs, and can not be procured to the best matching materials, taking into account the principles of the choice of surfacing materials, as well as the mechanical properties of various surfacing materials, analysis, materials selection and parent material similar to TIG-R34 (12Cr2MoWVTIB, Φ2.5 mm) wire. Using welding equipment
Lincoln V300-1, and arc welding supporting tools; temperature monitor the use of the United States MX2 infrared thermometer.
2 Welding Performance Analysis
According to carbon equivalent formula, the material 20Cr3MoWVA the main characteristics of carbon and alloy elements in more, welding and heat treatment weld areas prone to hardening body rigidity and joints while welding pieces of the stress is large, easily lead to cold cracking.
After nitriding treatment of the valve plate, the surface hardness up to HV900, welding cracks easily.
3 Welding Technology
3.1 Process Route
Welding pre-polishing cleaning - preheat - surfacing - post weld heat treatment - after welding turning.
3.2 The pre-welding
First, with the angle to the grinding wheel to remove a thorough clean-up parts of 20 mm surfacing within the nitrided layer, grinding depth should be larger than 0.4 mm, measurement of grinding parts of the hardness value, and to ensure that welding area to achieve the requirements of HB185 ~ 321 . According to JB4730-94 testing standards, check the orientation convex polished surface quality of the shoulder should not have cracks, defects such as slag, reaching the standard for qualified Grade Ⅰ.
And then cleaned with acetone valve plate weld and the surrounding area within 50 mm to ensure that water and oil; argon arc welding wire with sandpaper remove surface oil and rust spots and other dirt.
3.3 welding process and parameters of
Using oxyacetylene flame heating method of preheating before welding, preheating temperature of 350 ~ 400 ℃, with the thermometer measurement of preheating temperature. Valve plate welded parts exposed, other parts of cotton coated with stone to avoid arc burn. Parameters I = 80 ~ 90 A, argon gas flow rate 8 ~ 10L/min, DCEN voltage range 10 ~ 15 V, welding speed 30 ~ 45 mm / min, Every swing width ≤ 10 mm, the thickness of each layer surfacing ≤ 4 mm. Preheat temperatures after welding, the temperature control between layers 300 ~ 400 ℃, the welding process does not allow any defects, focusing on inspection cited, to close arc Office, found flaws with the angle grinder to remove immediately. To ensure the machining allowance, according to Figure surfacing size, diameter increased 5 mm, diameter reduction of 5 mm, piled high 13 mm. Side of the surfacing after the completion of surfacing on the other side.
Welding is complete, fire-resistant cotton coated with silicate slow cooling, welding parts of the cold to 100 ~ 150 ℃, local heat treatment immediately after welding. Heat treatment using flame heated to 640 ~ 660 ℃, heat 30 min, with the thermometer monitoring, heating rate and cooling rate were <300 ℃ / h, cooling to below 300 ℃ may from time to control, cooling blanket coated with aluminum silicate fiber slow cooling.
4 weld inspection
In accordance with process route to complete the surfacing and mechanical disc valves processed by penetrant inspection and ultrasonic testing inspection, there is no weld cracks, slag, porosity and other defects in the quality of welding quality has reached JB4730-94 standard grade Ⅰ requirements; in the processing surface hardness testing, the average hardness value of HB241, the original parent material hardness values similar to the use of performance to meet the workpiece.
5 Conclusion
2, Unit 1, the main steam pressure regulating valve repair welding and running nearly a year after the dissolution of the unit when the overhaul inspection, welding of the valve disc convex shoulders run through the 5 616 h did not find any problems. Can be seen with the TIG-R34 argon arc welding wire welding material used 20Cr3MoWVA preheated 350 ~ 400 ℃, after welding, 640 ~ 650 ℃, heat welding process 30 min treatment is reasonable and feasible. It not only solves the main steam pressure regulating valve to adjust the normal pairs of steam, while also saving money on the yuan.
ball valve Trunnion Mounted Ball Valve Floating Ball Valve Top Entry Ball Valve ball valve V Type Ball Valve
We can offer more Knife Gate Valve Information.If you need us according your spcification to produce the Knife Gate Valve .
Need, please e-mail to valve401@gmail.com
A high-pressure main steam valve repair program
1.1 The valve disc-oriented working mechanism of convex shoulder
Unit No. 2 for the manufacture of Dongfang Steam Turbine Works (N300-16.7/537/537-3 type) steam turbine, and its main steam pressure regulating valve is a main steam valves and 2 control valve composed of high-pressure regulating valve is used to regulate the amount of high-pressure steam into the cylinder. Unit run-time, the oil motive for mechanical lifting equipment, so that valve disc oriented convex shoulders move up and down along the guide slot, the control valve disc opening. Unit run-time, high-temperature steam control valve 16.7 MPa, 537 ℃, oriented primarily to withstand thermal stress convex shoulders and some weeks to shear stress.
No. 1 high-pressure regulating valve with the valve disc and valve seat diameter of 170 mm, the valve plate structure shown in Figure 1, oriented convex shoulder size 55 mm × 30 mm × 10 mm (H × W × thickness). Valve disc material used 20Cr3MoWVA alloy steel, in order to improve the resistance to cavitation valve disc performance, its surface temperature nitriding treatment conducted.
1.2 surfacing materials and welding equipment selection
According to the working conditions of control valve, the valve plate oriented convex shoulder it is necessary to ensure that there are sufficient high-temperature strength, but also to meet some wear. In view of crew repairs, and can not be procured to the best matching materials, taking into account the principles of the choice of surfacing materials, as well as the mechanical properties of various surfacing materials, analysis, materials selection and parent material similar to TIG-R34 (12Cr2MoWVTIB, Φ2.5 mm) wire. Using welding equipment
Lincoln V300-1, and arc welding supporting tools; temperature monitor the use of the United States MX2 infrared thermometer.
2 Welding Performance Analysis
According to carbon equivalent formula, the material 20Cr3MoWVA the main characteristics of carbon and alloy elements in more, welding and heat treatment weld areas prone to hardening body rigidity and joints while welding pieces of the stress is large, easily lead to cold cracking.
After nitriding treatment of the valve plate, the surface hardness up to HV900, welding cracks easily.
3 Welding Technology
3.1 Process Route
Welding pre-polishing cleaning - preheat - surfacing - post weld heat treatment - after welding turning.
3.2 The pre-welding
First, with the angle to the grinding wheel to remove a thorough clean-up parts of 20 mm surfacing within the nitrided layer, grinding depth should be larger than 0.4 mm, measurement of grinding parts of the hardness value, and to ensure that welding area to achieve the requirements of HB185 ~ 321 . According to JB4730-94 testing standards, check the orientation convex polished surface quality of the shoulder should not have cracks, defects such as slag, reaching the standard for qualified Grade Ⅰ.
And then cleaned with acetone valve plate weld and the surrounding area within 50 mm to ensure that water and oil; argon arc welding wire with sandpaper remove surface oil and rust spots and other dirt.
3.3 welding process and parameters of
Using oxyacetylene flame heating method of preheating before welding, preheating temperature of 350 ~ 400 ℃, with the thermometer measurement of preheating temperature. Valve plate welded parts exposed, other parts of cotton coated with stone to avoid arc burn. Parameters I = 80 ~ 90 A, argon gas flow rate 8 ~ 10L/min, DCEN voltage range 10 ~ 15 V, welding speed 30 ~ 45 mm / min, Every swing width ≤ 10 mm, the thickness of each layer surfacing ≤ 4 mm. Preheat temperatures after welding, the temperature control between layers 300 ~ 400 ℃, the welding process does not allow any defects, focusing on inspection cited, to close arc Office, found flaws with the angle grinder to remove immediately. To ensure the machining allowance, according to Figure surfacing size, diameter increased 5 mm, diameter reduction of 5 mm, piled high 13 mm. Side of the surfacing after the completion of surfacing on the other side.
Welding is complete, fire-resistant cotton coated with silicate slow cooling, welding parts of the cold to 100 ~ 150 ℃, local heat treatment immediately after welding. Heat treatment using flame heated to 640 ~ 660 ℃, heat 30 min, with the thermometer monitoring, heating rate and cooling rate were <300 ℃ / h, cooling to below 300 ℃ may from time to control, cooling blanket coated with aluminum silicate fiber slow cooling.
4 weld inspection
In accordance with process route to complete the surfacing and mechanical disc valves processed by penetrant inspection and ultrasonic testing inspection, there is no weld cracks, slag, porosity and other defects in the quality of welding quality has reached JB4730-94 standard grade Ⅰ requirements; in the processing surface hardness testing, the average hardness value of HB241, the original parent material hardness values similar to the use of performance to meet the workpiece.
5 Conclusion
2, Unit 1, the main steam pressure regulating valve repair welding and running nearly a year after the dissolution of the unit when the overhaul inspection, welding of the valve disc convex shoulders run through the 5 616 h did not find any problems. Can be seen with the TIG-R34 argon arc welding wire welding material used 20Cr3MoWVA preheated 350 ~ 400 ℃, after welding, 640 ~ 650 ℃, heat welding process 30 min treatment is reasonable and feasible. It not only solves the main steam pressure regulating valve to adjust the normal pairs of steam, while also saving money on the yuan.
ball valve Trunnion Mounted Ball Valve Floating Ball Valve Top Entry Ball Valve ball valve V Type Ball Valve
We can offer more Knife Gate Valve Information.If you need us according your spcification to produce the Knife Gate Valve .
Need, please e-mail to valve401@gmail.com
Traps Selection Guide
Traps must use the best quality products, limited funds should be used in the knife's edge. The use of high-quality trap of saving energy and increasing production efficiency of the capital investment than the purchase of the trap a few times higher. Use good quality trap can provide a huge economic benefits. The use of a wide range of trap a large amount of 10 million can not be ignored, competent leaders at all levels should attach great importance.
Select steam traps require an accurate and precise blocking drainage, high sensitivity, can improve the utilization of steam is not leaking steam, work performance, reliable, high back pressure, long service life, easy maintenance is the preferred condition.
1. In the production process of heat transfer equipment, drying room, fast heat exchangers, distillation equipment, such as the need for fast heat up, there does not allow the production of condensed water heating equipment, we should use mechanical-type traps.
Mechanical-type traps are not working temperature and pressure changes, water that is Pai, undercooling is small, do not water in heating devices, can make heating equipment to achieve optimum operating temperature. Free float steam trap in which the structure of the most advanced, very sensitive, the smallest undercooling 0 ° C, condensing water saturation temperature can be ranked, no steam leakage, merits the highest heating equipment can achieve the best efficiency. Production process heating equipment is the best trap.
2. In steam pipe, with heat pipes, small heating equipment, heating equipment, temperature less demanding steam equipment, we should use static-type traps heat.
Static thermal cooling degree-type traps, Pai condensing water temperature is low, you can take full advantage of high-temperature sensible heat of condensation of water, energy-saving effect is good. Bellows steam trap in which the structure of the most advanced, no manual adjustment is very sensitive, maximum cooling rate has been 15 ℃ and 30 ℃ for the selection of two kinds of film boxes, not afraid of cold, small size, any position can be installed, in the pipeline repair and replacement of the valve core can save money and labor, long life and broad scope of application is static-type traps heat boutique.
3. In the high temperature and pressure superheated steam piping and equipment, should use special trap superheated steam.
Superheated steam traps in high-temperature, high pressure, low load operating conditions to isolate the bad disappear superheated steam produced by high-temperature condensate. One disc-type steam trap to use pipe insulation on the steam trap of the main steam rooms insulation, advanced structure, in the absence of condensate case, trap firmly closed, the work of high quality, long life, is a high-pressure hot special trap steam.
ball valve Trunnion Mounted Ball Valve Floating Ball Valve Top Entry Ball Valve ball valve V Type Ball Valve
We can offer more Knife Gate Valve Information.If you need us according your spcification to produce the Knife Gate Valve .
Need, please e-mail to valve401@gmail.com
Select steam traps require an accurate and precise blocking drainage, high sensitivity, can improve the utilization of steam is not leaking steam, work performance, reliable, high back pressure, long service life, easy maintenance is the preferred condition.
1. In the production process of heat transfer equipment, drying room, fast heat exchangers, distillation equipment, such as the need for fast heat up, there does not allow the production of condensed water heating equipment, we should use mechanical-type traps.
Mechanical-type traps are not working temperature and pressure changes, water that is Pai, undercooling is small, do not water in heating devices, can make heating equipment to achieve optimum operating temperature. Free float steam trap in which the structure of the most advanced, very sensitive, the smallest undercooling 0 ° C, condensing water saturation temperature can be ranked, no steam leakage, merits the highest heating equipment can achieve the best efficiency. Production process heating equipment is the best trap.
2. In steam pipe, with heat pipes, small heating equipment, heating equipment, temperature less demanding steam equipment, we should use static-type traps heat.
Static thermal cooling degree-type traps, Pai condensing water temperature is low, you can take full advantage of high-temperature sensible heat of condensation of water, energy-saving effect is good. Bellows steam trap in which the structure of the most advanced, no manual adjustment is very sensitive, maximum cooling rate has been 15 ℃ and 30 ℃ for the selection of two kinds of film boxes, not afraid of cold, small size, any position can be installed, in the pipeline repair and replacement of the valve core can save money and labor, long life and broad scope of application is static-type traps heat boutique.
3. In the high temperature and pressure superheated steam piping and equipment, should use special trap superheated steam.
Superheated steam traps in high-temperature, high pressure, low load operating conditions to isolate the bad disappear superheated steam produced by high-temperature condensate. One disc-type steam trap to use pipe insulation on the steam trap of the main steam rooms insulation, advanced structure, in the absence of condensate case, trap firmly closed, the work of high quality, long life, is a high-pressure hot special trap steam.
ball valve Trunnion Mounted Ball Valve Floating Ball Valve Top Entry Ball Valve ball valve V Type Ball Valve
We can offer more Knife Gate Valve Information.If you need us according your spcification to produce the Knife Gate Valve .
Need, please e-mail to valve401@gmail.com
Sunday, September 26, 2010
Temperature Control Valve Selection
With the heating system reform, household heat metering and sub-room temperature control has entered the implementation stage, the temperature control valve is installed in the radiator is already very popular, and with the temperature control valve to achieve sub-room temperature control, both the maximum energy conservation, but also satisfy different user needs for indoor temperature regulation is a good thing benefits the country, but how to select temperature control valve did not fully allow users to grasp, if not the right choice of products, not only to can not meet demand, and may give users an unnecessary economic losses, for which the author according to their own application experience, in which published some of my views, designed to give colleagues and users some useful help.
Temperature control valve is installed on the water pipes in the radiator temperature regulation (actually flow regulation) of a device. Manual and automatic temperature control valve is divided into two kinds of temperature control valve, automatic temperature control valve is also called Self-operated temperature control valve or automatic thermostat valve, are also referred to as the thermostat valve. Automatic temperature control valve is a temperature sensor Self-executing agencies and special supporting temperature control valve body composition
Thermostatic valve valve's structure often straight, angle valve two of the most common two-way valve. Two-way valve is mainly used for two-pipe system or a specially designed a new single-pipe system. In recent years, according to single and double pipe system differences, but also post-graduate output of a single-pipe system specifically applicable to the three links-style temperature control valve and the use of covert installation of suitable single-, double-tube system, a special four-way valve. The four-way valve is currently more common in imported products, such as Italy Jiekemini (GIACOMI-NI) of the four-way valve, which applies not only to all kinds of radiators, and it applies to single and double control systems, but also the ability to to meet the dark filled with a variety of pipe connections.
Thermostatic valve usually have manual, automatic two kinds, the principle of the valve movements are very different. Manual temperature control valve usually spiral lift spool, rotating handle designed a straight line through the spiral into a spool displacement. And automatic temperature control valve in order to meet the temperature sensor specific self-implementing agency of the straight-line moves, spool movement is usually designed to automatically reset the direct linear displacement, therefore the body under normal circumstances are not interchangeable. But there are also interchangeable, a specially designed valve can be generic, that is, automatic temperature control valve of the valve, attach a suitable manual screw lifting mechanism, can be realized manually, automatic common exchange between the two. This is particularly suitable to improve the situation in China have great practical value, in the present, many projects, developers in order to save the initial investment, first install a valve with automatic temperature control feature along with the spiral movements with special handles, so that both the achieved with 1 / 3 the cost of automatic temperature control valve (the price of basic equivalent to manual temperature control valve) for a manual temperature control valve, and gave the user automatic temperature control in the future to upgrade the space left behind. Even in the imports of this product is also rare in this area of Italy Jiekemini walk in front of the market provides such a range of manual, automatic temperature control valve between a known pairs adjustable temperature control valve, eight stalls setting, the indoor temperature as you set up, extremely convenient. Worthy of the world's larger HVAC valve suppliers. It is this range of manual and automatic temperature control valve of the valve between the particularity of, so choice will be complex, this complexity is not fine for some business people and caused speculation salesman "fish in" The opportunities. In this I remind that, in the current market there are a lot of automatic temperature control valve suppliers salesman will carry a simple adjustment handle automatic temperature control valve body of the net charge as a dual regulatory function of the temperature control valve to the user recommended, and some users to use such a temperature control valve, which is not very appropriate, there are great risks, so that although the automatic temperature control valve body with a simple adjustment on the handle, but the handle design idea of the automatic temperature control valve in order to meet the valve before the first installation of temporary works for the system adjusted to meet the test of water pressure test only, test the water pressure in the test process is completed, be replaced by automatic temperature control valve valve head, because it temporary, so the easy adjustment of the valve handle on the original loan for a fixed temperature control valve head for helical screw lifting the ordinary use. We all know that simple adjustment handle because of its temporary, one-time, generally use plastic, if used as the final frequency adjustment, the thread wear is very fast, not to mention working in the heating system, the spool up and down movements where there is a certain pressure circumstances, even in the absence of pressure systems, the spool itself alone will greatly speed up the spring pressure on the thread handle wear and tear, so use this product as can be upgraded to automatic temperature control valve of the Manual temperature control valve is not appropriate.
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Temperature control valve is installed on the water pipes in the radiator temperature regulation (actually flow regulation) of a device. Manual and automatic temperature control valve is divided into two kinds of temperature control valve, automatic temperature control valve is also called Self-operated temperature control valve or automatic thermostat valve, are also referred to as the thermostat valve. Automatic temperature control valve is a temperature sensor Self-executing agencies and special supporting temperature control valve body composition
Thermostatic valve valve's structure often straight, angle valve two of the most common two-way valve. Two-way valve is mainly used for two-pipe system or a specially designed a new single-pipe system. In recent years, according to single and double pipe system differences, but also post-graduate output of a single-pipe system specifically applicable to the three links-style temperature control valve and the use of covert installation of suitable single-, double-tube system, a special four-way valve. The four-way valve is currently more common in imported products, such as Italy Jiekemini (GIACOMI-NI) of the four-way valve, which applies not only to all kinds of radiators, and it applies to single and double control systems, but also the ability to to meet the dark filled with a variety of pipe connections.
Thermostatic valve usually have manual, automatic two kinds, the principle of the valve movements are very different. Manual temperature control valve usually spiral lift spool, rotating handle designed a straight line through the spiral into a spool displacement. And automatic temperature control valve in order to meet the temperature sensor specific self-implementing agency of the straight-line moves, spool movement is usually designed to automatically reset the direct linear displacement, therefore the body under normal circumstances are not interchangeable. But there are also interchangeable, a specially designed valve can be generic, that is, automatic temperature control valve of the valve, attach a suitable manual screw lifting mechanism, can be realized manually, automatic common exchange between the two. This is particularly suitable to improve the situation in China have great practical value, in the present, many projects, developers in order to save the initial investment, first install a valve with automatic temperature control feature along with the spiral movements with special handles, so that both the achieved with 1 / 3 the cost of automatic temperature control valve (the price of basic equivalent to manual temperature control valve) for a manual temperature control valve, and gave the user automatic temperature control in the future to upgrade the space left behind. Even in the imports of this product is also rare in this area of Italy Jiekemini walk in front of the market provides such a range of manual, automatic temperature control valve between a known pairs adjustable temperature control valve, eight stalls setting, the indoor temperature as you set up, extremely convenient. Worthy of the world's larger HVAC valve suppliers. It is this range of manual and automatic temperature control valve of the valve between the particularity of, so choice will be complex, this complexity is not fine for some business people and caused speculation salesman "fish in" The opportunities. In this I remind that, in the current market there are a lot of automatic temperature control valve suppliers salesman will carry a simple adjustment handle automatic temperature control valve body of the net charge as a dual regulatory function of the temperature control valve to the user recommended, and some users to use such a temperature control valve, which is not very appropriate, there are great risks, so that although the automatic temperature control valve body with a simple adjustment on the handle, but the handle design idea of the automatic temperature control valve in order to meet the valve before the first installation of temporary works for the system adjusted to meet the test of water pressure test only, test the water pressure in the test process is completed, be replaced by automatic temperature control valve valve head, because it temporary, so the easy adjustment of the valve handle on the original loan for a fixed temperature control valve head for helical screw lifting the ordinary use. We all know that simple adjustment handle because of its temporary, one-time, generally use plastic, if used as the final frequency adjustment, the thread wear is very fast, not to mention working in the heating system, the spool up and down movements where there is a certain pressure circumstances, even in the absence of pressure systems, the spool itself alone will greatly speed up the spring pressure on the thread handle wear and tear, so use this product as can be upgraded to automatic temperature control valve of the Manual temperature control valve is not appropriate.
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Experts teach you how to properly use the valve (I)
Medium used as a cut-off valve in the full-time through the entire flow, this time the pressure medium to run minimal loss. Valve is usually applied to less frequent open and close, but also to maintain full-or full-closed gate of the working conditions. Does not apply to the use of a regulator or throttling. For high-speed flow of medium, open the gate in local conditions can cause the vibration of the gate, but they may damage the vibration damper and the valve seat sealing surface, while the throttling damper will suffer erosion of the medium. From a structural form, the main difference is that the sealing component used in the form of. According to the form of sealed components, often divided into several different types of valve, such as: wedge gate valve, parallel-type valve, parallel Shuangzha plate gate valve, wedge gate, etc. Shuangzha board. The most common form of wedge gate valves and parallel-type valve. Valve
As the valve stem and valve seat sealing surface perpendicular to the axis. Valve stem to open or close the trip is relatively short, and has very reliable cutting action, makes this valve ideally suited as a medium and cutting off or regulate the use of. Cut-off valve when the valve flap in the open position, and its valve seat and valve sealing surface is no longer between the contacts and has a very reliable cutting action, and combine this valve is suitable as a medium to cut off or adjust and cutting use.
Once the cut-off valve is turned on, its seat and the valve between the valve sealing surface is no longer in contact, so it's a smaller sealing surface mechanical wear, as most of the cut-off valve seat and valve flap is easier to repair or replace When sealing element is not required to remove the entire valve from the pipeline to which the valve and pipeline welding for the occasion into one is very applicable. Medium through such valve when the flow direction changed, so a higher cut-off valve of the flow resistance in other valves. |
Commonly used cut-off valves are the following: 1) Angle type globe valve; in angle-type stop valve, the fluid simply by changing a direction, so that through this valve on the pressure drop than the conventional structure of small cut-off valve. 2) DC-type cut-off valve; in the DC-type or Y-shaped cut-off valve, the valve of the flow channel and mainstream Road into a slash, so that movement of the state extent of the damage is smaller than the conventional cut-off valve, so the pressure loss through the valve is also the corresponding smaller. 3) The plunger-type valve: This form of cut-off valve is a variant of conventional cut-off valve. In the valve, the valve flap and valve seats are usually based on the plunger principle of design. Polished into a flap valve stem is connected with the plunger, the plunger seal is on the two sets of flexible seals achieved. Two elastic rings separated by a ring, and through a valve cover nut the load exerted on the valve cover seals around the plunger pressure prison. Elastic ring can be replaced, you can use a variety of material, the valve is mainly used for "open" or "off", but with a special form of plunger or special rings can also be used to adjust flow.
Butterfly
Butterfly valve butterfly plate installed in the direction of the pipe diameter. Cylindrical channel in the valve body, the disc-shaped butterfly plate around the axis of rotation, rotation angle of 0 ° ~ 90 ° between the rotation to 90 ° when the valve is fully open state license.
Butterfly simple structure, small size, light weight, only by a small number of parts. And just rotate 90 ° to quickly open and close, easy to operate, while the flow control valve has a good feature. Butterfly in the fully open position, the butterfly plate thickness is only when the medium flows through the valve body resistance through the valve so the pressure drop generated by small, it has good flow control characteristics. There are shells and metal sealing butterfly valve seal two kinds of sealed type. Elastic sealing valves, seals can be mounted on the body or attached to the butterfly board peripheral.
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As the valve stem and valve seat sealing surface perpendicular to the axis. Valve stem to open or close the trip is relatively short, and has very reliable cutting action, makes this valve ideally suited as a medium and cutting off or regulate the use of. Cut-off valve when the valve flap in the open position, and its valve seat and valve sealing surface is no longer between the contacts and has a very reliable cutting action, and combine this valve is suitable as a medium to cut off or adjust and cutting use.
Once the cut-off valve is turned on, its seat and the valve between the valve sealing surface is no longer in contact, so it's a smaller sealing surface mechanical wear, as most of the cut-off valve seat and valve flap is easier to repair or replace When sealing element is not required to remove the entire valve from the pipeline to which the valve and pipeline welding for the occasion into one is very applicable. Medium through such valve when the flow direction changed, so a higher cut-off valve of the flow resistance in other valves. |
Commonly used cut-off valves are the following: 1) Angle type globe valve; in angle-type stop valve, the fluid simply by changing a direction, so that through this valve on the pressure drop than the conventional structure of small cut-off valve. 2) DC-type cut-off valve; in the DC-type or Y-shaped cut-off valve, the valve of the flow channel and mainstream Road into a slash, so that movement of the state extent of the damage is smaller than the conventional cut-off valve, so the pressure loss through the valve is also the corresponding smaller. 3) The plunger-type valve: This form of cut-off valve is a variant of conventional cut-off valve. In the valve, the valve flap and valve seats are usually based on the plunger principle of design. Polished into a flap valve stem is connected with the plunger, the plunger seal is on the two sets of flexible seals achieved. Two elastic rings separated by a ring, and through a valve cover nut the load exerted on the valve cover seals around the plunger pressure prison. Elastic ring can be replaced, you can use a variety of material, the valve is mainly used for "open" or "off", but with a special form of plunger or special rings can also be used to adjust flow.
Butterfly
Butterfly valve butterfly plate installed in the direction of the pipe diameter. Cylindrical channel in the valve body, the disc-shaped butterfly plate around the axis of rotation, rotation angle of 0 ° ~ 90 ° between the rotation to 90 ° when the valve is fully open state license.
Butterfly simple structure, small size, light weight, only by a small number of parts. And just rotate 90 ° to quickly open and close, easy to operate, while the flow control valve has a good feature. Butterfly in the fully open position, the butterfly plate thickness is only when the medium flows through the valve body resistance through the valve so the pressure drop generated by small, it has good flow control characteristics. There are shells and metal sealing butterfly valve seal two kinds of sealed type. Elastic sealing valves, seals can be mounted on the body or attached to the butterfly board peripheral.
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Different characteristics of the valve connection and application
(1) thread connection valve. This connection is usually processed ends of the valve and out into the cone tube or straight pipe thread which allows it to connect to the tapered pipe thread joint or possession of the road. Because of this connection may have been a leak channel, it can be used sealants, sealing tape or filler to plug the channel. If the valve body material can be welded, but the very different expansion coefficients, or the rate of temperature change in the scope of a larger thread junction honey must be welded.
Thread connecting the valve is mainly Nominal been in 50mm below the valve. If the diameter size is too large, the Ministry of the installation and sealing connection very difficult.
For ease of installation and removal of threaded connection of valves in the piping system, the appropriate position is available fittings. Nominal diameter 50mm below the valve in the tube section can be used as pipe joints, pipe thread socket will connect the two parts together.
(2) The flange valve. Flange valve, its installation and removal are more convenient. However, bulky than the thread to connect the valve, the corresponding prices higher value. Therefore, it applies to a variety of diameter and pressure pipe connection. However, when the temperature over 350 degrees, due to bolts, gaskets and flange a variable relaxation, but also significantly reduce the load on bolts on the flange force likely to produce significant leakage.
(3) Welding connection valve. This connection applies to all kinds of pressure and temperature, in the more Dutch engraved under the conditions of use, more reliable than the flange connection. However, the valve welded connections dismantling and re-install it rather difficult, so its use is usually limited to long-term reliable operation, or use Dutch engraving, higher temperatures occasions. Such as thermal power stations, nuclear power engineering, the ethylene project pipeline.
Nominal diameter in 50mm below the welding socket weld valves usually have to take over Dutch side of the channel plane. As in the socket and the pipe socket weld formed between the cracks, and thus has the potential to crevice corrosion by certain media, while the vibration of pipeline will connect parts of fatigue, so the use of socket welding subject to certain restrictions.
In the nominal diameter greater use Dutch engraving, high temperature of the occasion, valve often used for welding groove, while the original mesh welding seam has to be sought for selection of technically proficient welders to complete this work. ball valve Trunnion Mounted Ball Valve Floating Ball Valve Top Entry Ball Valve ball valve V Type Ball Valve
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Thread connecting the valve is mainly Nominal been in 50mm below the valve. If the diameter size is too large, the Ministry of the installation and sealing connection very difficult.
For ease of installation and removal of threaded connection of valves in the piping system, the appropriate position is available fittings. Nominal diameter 50mm below the valve in the tube section can be used as pipe joints, pipe thread socket will connect the two parts together.
(2) The flange valve. Flange valve, its installation and removal are more convenient. However, bulky than the thread to connect the valve, the corresponding prices higher value. Therefore, it applies to a variety of diameter and pressure pipe connection. However, when the temperature over 350 degrees, due to bolts, gaskets and flange a variable relaxation, but also significantly reduce the load on bolts on the flange force likely to produce significant leakage.
(3) Welding connection valve. This connection applies to all kinds of pressure and temperature, in the more Dutch engraved under the conditions of use, more reliable than the flange connection. However, the valve welded connections dismantling and re-install it rather difficult, so its use is usually limited to long-term reliable operation, or use Dutch engraving, higher temperatures occasions. Such as thermal power stations, nuclear power engineering, the ethylene project pipeline.
Nominal diameter in 50mm below the welding socket weld valves usually have to take over Dutch side of the channel plane. As in the socket and the pipe socket weld formed between the cracks, and thus has the potential to crevice corrosion by certain media, while the vibration of pipeline will connect parts of fatigue, so the use of socket welding subject to certain restrictions.
In the nominal diameter greater use Dutch engraving, high temperature of the occasion, valve often used for welding groove, while the original mesh welding seam has to be sought for selection of technically proficient welders to complete this work. ball valve Trunnion Mounted Ball Valve Floating Ball Valve Top Entry Ball Valve ball valve V Type Ball Valve
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Pneumatic control valve maintenance method and cause of the malfunction
Pneumatic control valve is widely used in petroleum chemical industry is one of the instrument. It is precisely to work properly in ensuring the normal operation of process plants and production safety have an important significance. Therefore, strengthening the pneumatic valve repair is necessary.
First, repair parts, when the focus of inspection
Check between the body wall: In high-pressure differential and corrosive media of the occasion, body wall, diaphragm of the diaphragm often media impact and corrosion, we must focus on examination of pressure decay;
Check Seat: Due to the work of media penetration, fixed seat screw used in the inner surface susceptible to corrosion Ershi seat relaxation;
Check spool: spool valve to regulate one of movable parts, subject to more severe erosion of the medium, repair should be careful when you check the valve core ministries is corrosion, wear and tear, especially in the case of high-pressure differential, spool of wear due to cavitation caused by cavitation phenomenon is even more serious. Were seriously damaged valve core should be replaced; check Filler: Check the packing asbestos rope is dry, such as the use of PTFE packing, should pay attention to check whether the aging and its mating surface is damaged;
Check the executive body of the rubber membrane is aging, whether the cracking phenomenon.
2, pneumatic control valve with daily maintenance
When the control valve using graphite asbestos as a filler, the filler should be about three months to add a lubricant to ensure the control valve and flexible easy to use. Found filling pressure cap low, should be added fillers, such as found in the dry filler PTFE B sclerosis, should be promptly replaced; should pay attention to inspection tour of the operation of control valve, check valve position indicator and regulator the output is consistent; to have locator control valve should always check the gas source, identify problems and timely treatment; should always maintain a control valve components of health as well as a complete easy to use.
3, common faults and their causes
(A) the control valve does not move. Phenomenon and the reasons for failure are as follows:
1. No signal, no gas source. ① gas source is not open, ② gas supply due to water freezing in the winter, leading to blocked ducts or filters, valve block failure, ③ compressor failure; ④ source of mains gas leak.
2. There is gas source, no signal. ① regulator failure, ② the signal tube leakage; ③ bellows leak locator; ④ regulate film damaged retina.
3. Locator without gas supply. ① filter plugging; ② valve failure I ③ pipeline leak or blockage.
4. Locator has gas supply, no output. Locator orifice plug.
5. There is signal, no action. Spool off ①, ② spool with the social or stuck with the valve seat; ③ stem bending or breakage; ④ spool seat block of frozen or coke dirt; ⑤ implementing agencies do not have the spring due to the long-term rust die.
(B) the control valve moves instability. Phenomenon and the reasons for failure are as follows:
1. The pressure gas source of instability. ① compressor capacity is too small; ② valve failure.
2. Signal pressure instability. ① control system time constant (T = RC) inappropriate; ② regulator output instability.
3. Gas source pressure stable, the signal pressure is stable, but still stable valve action. ① Locator amplifier ball wear off by the dirt loose, especially with increasing gas consumption will produce the output shock; ② Locator amplifier nozzle baffle is not parallel to baffle nozzle cover not live; ③ Output Pipe, line leak; ④ executive body rigidity is too small; ⑤ stem movement friction large parts of a block in contact with the phenomenon.
(C) regulating valve vibration. Phenomenon and the reasons for failure are as follows:
1. Regulating valve opening at any vibration at all times. ① supporting instability; ② near the source of vibration; ③ spool and bushing wear serious.
2. Regulating valve near the fully closed position vibration. ① big selection valve, often used in small openings; ② single-seat valve media flow on and off in the opposite direction.
(D) regulating valve movements slow. Slow phenomenon, and the following reasons:
1. Stem moves in one direction only when the slow. ① pneumatic membrane leakage of the implementing agencies in the membrane damage; ② implementing agencies in the "O" type seal leakage.
2. Stem at reciprocating movements are slow, when the phenomenon. ① valve body with sticky material to plug; ② sclerosis or graphite PTFE packing deterioration of asbestos packing a dry lubricant; ③ packing too tightly increases, friction increases; ④ stem not directly lead to friction due to large; ⑤ No The pneumatic control valve positioner can lead to slow movement.
(E) increase the amount of valve leakage. Leakage of the following reasons:
1. Valve fully closed when the leakage of large quantities. ① spool is worn to a serious internal leakage, ② strictly off valve is not a good tune.
2. Valve fail to fully closed position. ① medium pressure too great, the executing agency rigidity is small, loose valve closed; ② of a foreign body within the valve; ③ sintered bushing.
(F) adjustable flow range becomes smaller. The main reason is corrosion smaller spool, so that the minimum flow rate adjustable larger.
Pneumatic control valve failure to understand the phenomenon and the reasons to be symptomatic to take measures to resolve it.
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Sunday, September 19, 2010
Affect the safe operation of the factors regulating valve and Countermeasures (Part Two)
3.3 spool, valve leakage deformation
Valve core, valve leakage was mainly caused by the production process control valve in the casting or forging defects can lead to corrosion strengthened. The corrosive medium through the fluid medium can also result in erosion control valve leakage. Erosion or corrosion mainly exists in the form of cavitation. When the corrosive medium through the valve, it will give rise to spool, valve seat materials, erosion and impact so that valve core, valve seat into an oval or other shape, as time goes on, leading to valve core, valve seat is not matching, there is clearance, Guan lax leak. | MechNet | more knowledge, please visit the China National Machinery and network of experts, http://www.mechnet.com.cn/
Solution: The key to a good valve core, valve seat material selection customs, quality. Select corrosion-resistant materials, Ma points, trachoma and other defective products and resolutely removed. If the valve core, valve seat deformation is not serious, can grind through the fine sandpaper to remove traces, improve sealing finish to improve sealing performance. If serious damage, it should be re-replaced with new valves. | MechNet | more knowledge, please visit the China National Machinery and network of experts, http://www.mechnet.com.cn/
4, oscillation
Control valve spring stiffness of inadequate control valve output signal instability could easily cause a drastic change in valve oscillation. Also that the election of the frequency of the system valve or pipe the same frequency, base severe vibration, so that control valve resulting vibrations. Selection of improper valve working in a small opening there is a violent flow resistance, velocity, pressure changes, when more than valve stiffness, stability deteriorated, severe oscillation.
Solutions: As the oscillation are many reasons, so the concrete analysis of specific problems. A slight vibration vibration, can increase the stiffness to eliminate. Chooses to use the large stiffness of spring, use piston implementation structures. Pipeline, the base support by increasing the elimination of severe shock vibration interference; selected valve the same as the frequency and system frequency, then switch to a different structure of the valve; work in the small openings caused by the oscillation, it is improper selection of flow capacity of C values of selected large, Selection of capacity C must be re-circulation of the value of the smaller or using sub-process control valves, or Picture-regulating valve in order to overcome the work of a small opening.
5, valve positioner faults
5.1 Common locator using mechanical force balance principle, namely nozzle baffle technology, mainly in the following fault types:
1) the use of mechanical force balance principle of work and its moving parts are more susceptible to temperature, vibration, resulting in control valve fluctuations;
2) The nozzle shield technology, due to the nozzle hole is very small, prone to dust or clean gas source block is the locator does not work;
3) Use of force balance principle, elasticity of the spring occurs in adverse changes in the scene, resulting in non-linear lead to the control valve decline in the quality.
5.2 Smart Positioning is controlled by the microprocessor (cpu), A / D, D / A converter and other components, whose working principle and common Locator different. For a given value and actual value comparison of purely electric signal, is no longer a force balance. Therefore, to overcome the conventional force balance locator shortcomings. However, for emergency parking lot timely, such as emergency shut-off valves, emergency venting valve. These valves require stationary at a certain location, only an emergency occurs, it requires good movement. Prolonged stay in a location easy for the electric converter small-signal does not cause uncontrolled movements of hazardous situations. In addition, the valve position sensor for the potentiometer as a result of on-site, easy to change in resistance value caused by the small-signal non-action, large-signal full-hazards. Therefore, in order to ensure the reliability and intelligent positioning device availability, they must be frequently tested.
6, Conclusion
By regulating valve failure cause analysis and take appropriate treatment, improved methods will greatly enhance the utilization of regulating valve to reduce instrument failure rate, the process technology to improve production efficiency and cost-effective and energy consumption all have an important role in reducing can effectively improve the quality of conditioning systems, thereby ensuring long-cycle production plants running.
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Valve core, valve leakage was mainly caused by the production process control valve in the casting or forging defects can lead to corrosion strengthened. The corrosive medium through the fluid medium can also result in erosion control valve leakage. Erosion or corrosion mainly exists in the form of cavitation. When the corrosive medium through the valve, it will give rise to spool, valve seat materials, erosion and impact so that valve core, valve seat into an oval or other shape, as time goes on, leading to valve core, valve seat is not matching, there is clearance, Guan lax leak. | MechNet | more knowledge, please visit the China National Machinery and network of experts, http://www.mechnet.com.cn/
Solution: The key to a good valve core, valve seat material selection customs, quality. Select corrosion-resistant materials, Ma points, trachoma and other defective products and resolutely removed. If the valve core, valve seat deformation is not serious, can grind through the fine sandpaper to remove traces, improve sealing finish to improve sealing performance. If serious damage, it should be re-replaced with new valves. | MechNet | more knowledge, please visit the China National Machinery and network of experts, http://www.mechnet.com.cn/
4, oscillation
Control valve spring stiffness of inadequate control valve output signal instability could easily cause a drastic change in valve oscillation. Also that the election of the frequency of the system valve or pipe the same frequency, base severe vibration, so that control valve resulting vibrations. Selection of improper valve working in a small opening there is a violent flow resistance, velocity, pressure changes, when more than valve stiffness, stability deteriorated, severe oscillation.
Solutions: As the oscillation are many reasons, so the concrete analysis of specific problems. A slight vibration vibration, can increase the stiffness to eliminate. Chooses to use the large stiffness of spring, use piston implementation structures. Pipeline, the base support by increasing the elimination of severe shock vibration interference; selected valve the same as the frequency and system frequency, then switch to a different structure of the valve; work in the small openings caused by the oscillation, it is improper selection of flow capacity of C values of selected large, Selection of capacity C must be re-circulation of the value of the smaller or using sub-process control valves, or Picture-regulating valve in order to overcome the work of a small opening.
5, valve positioner faults
5.1 Common locator using mechanical force balance principle, namely nozzle baffle technology, mainly in the following fault types:
1) the use of mechanical force balance principle of work and its moving parts are more susceptible to temperature, vibration, resulting in control valve fluctuations;
2) The nozzle shield technology, due to the nozzle hole is very small, prone to dust or clean gas source block is the locator does not work;
3) Use of force balance principle, elasticity of the spring occurs in adverse changes in the scene, resulting in non-linear lead to the control valve decline in the quality.
5.2 Smart Positioning is controlled by the microprocessor (cpu), A / D, D / A converter and other components, whose working principle and common Locator different. For a given value and actual value comparison of purely electric signal, is no longer a force balance. Therefore, to overcome the conventional force balance locator shortcomings. However, for emergency parking lot timely, such as emergency shut-off valves, emergency venting valve. These valves require stationary at a certain location, only an emergency occurs, it requires good movement. Prolonged stay in a location easy for the electric converter small-signal does not cause uncontrolled movements of hazardous situations. In addition, the valve position sensor for the potentiometer as a result of on-site, easy to change in resistance value caused by the small-signal non-action, large-signal full-hazards. Therefore, in order to ensure the reliability and intelligent positioning device availability, they must be frequently tested.
6, Conclusion
By regulating valve failure cause analysis and take appropriate treatment, improved methods will greatly enhance the utilization of regulating valve to reduce instrument failure rate, the process technology to improve production efficiency and cost-effective and energy consumption all have an important role in reducing can effectively improve the quality of conditioning systems, thereby ensuring long-cycle production plants running.
ball valve Trunnion Mounted Ball Valve Floating Ball Valve Top Entry Ball Valve Three way ball valve V Type Ball Valve
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Multifunctional Pump Control Valve technical requirements
The standard applies to nominal pressure for PN1.0MPa-PN4.0MPa, nominal diameter of DN50mm-DN1200mm multifunctional pump control valve.
Now the standard technical requirements described below:
1 Pressure - temperature degree-level
Multifunctional Pump Control Valve Pressure - temperature rating from the shell, inner parts and control of materials management system, the pressure - temperature rating determined. Multifunctional Pump Control Valve at a temperature of the maximum allowable working pressure to take the shell, internal parts and control tube system materials in the temperature value of the maximum allowable working pressure in the small value.
1.1 The iron shell pressure - temperature rating should be consistent with GB/T17241.7 requirements.
1.2 steel shell of the pressure - temperature rating should be consistent with GB/T9124 requirements.
1.3 For the GB/T17241.7, GB/T9124 does not provide the pressure - temperature rating of the material, according to the relevant standards or design requirements.
2 Body
2.1 Body Flange
Flange shall be cast with the body as a whole. Iron flange type and dimensions should be consistent with the provisions of GB/T17241.6 technical conditions should be consistent GB/T17241.7 requirements; steel flange type and dimensions should be consistent with the provisions of GB/T9113.1 and technological conditions should be consistent with GB/T9124 requirements.
2.2 The length of the valve structure.
2.3 The minimum wall thickness of valve
The minimum wall thickness of cast iron valve body GB/T13932-1992 Table 3 should be consistent with the provisions of the minimum wall thickness of steel body parts should be consistent with the provisions of JB/T8937-1999 Table 1.
3 piece tectorial membrane valve seat
3.1 valve cover and the diaphragm seat, diaphragm valve seat and the connection type should be used flange.
3.2 diaphragm and valve seat shall not be less than the number of connecting bolts 4.
3.3 valve cover and the diaphragm seat a minimum wall thickness according to the requirements of 2.3.
3.4 valve cover flange and the diaphragm seat should be rounded. Flange sealing surface of the planar pattern can be used, sudden surface-type or concave-convex type.
4 Stem, slow-closing valve plate, the main valve plate | MechNet | welcome to visit the China National Machinery network of experts www.MechNet.com.cn
4.1 slow-closing valve plate and valve stem should be connected fastening and reliable.
4.2 slow-closing valve plate with the main valve plate sealing type metal seal pattern should be used.
4.3 The main valve plate and valve stem must slide a flexible and reliable.
4.4 the main valve plate and the main valve seat seal plate can be used two kinds of metal sealing and non-metallic sealing type.
5 Diaphragm
5.1 patch performance should conform to Table 2 (see next page) requirements. | MechNet | welcome to visit the China National Machinery network of experts www.MechNet.com.cn
5.2 Diaphragm appearance quality should be consistent with HG/T3090 requirements.
5.3 when applied to drinking water, the diaphragm material should be consistent with GB/T17219 security requirements.
6 Control Management Information System
Control systems control the various components should be able to withstand the maximum working pressure valve, the parts can not leak.
7 Materials
7.1 The main parts of the selection of appropriate materials, according to JB/T5300 requirements.
7.2 Copper alloy castings shall comply with the provisions of GB/T12225; GB/T12226 gray iron castings shall comply with the provisions of its tensile strength shall be not less than 200MPa; ductile iron castings shall comply with the provisions of GB/T12227; carbon steel castings shall comply with GB/T12229 requirements; GB/T12230 austenitic steel castings shall comply with requirements.
7.3 Multifunctional Pump Control Valve Steel Casting JB/T7927 appearance quality should meet the provisions of multifunctional pump control valve cast iron appearance quality reference JB/T7927 requirements.
8 shell strength
Multifunctional Pump Control Valve shell strength should be consistent with GB/T13927 requirements.
9 sealing performance
Multifunctional pump control valve sealing performance should be consistent with GB/T13927 requirements.
10 Cleanliness
Multifunctional Pump Control Valve JB/T7748 cleanliness should meet the requirements.
11 Painting
When applied to drinking water, the multifunctional pump control valve cavity coating material should be consistent with GB/T17219 security requirements. Outer surface of the coating is not provided for, the special requirements specified in the order in the contract. ball valve Trunnion Mounted Ball Valve Floating Ball Valve Top Entry Ball Valve Three way ball valve V Type Ball Valve
We can offer more Knife Gate Valve Information.If you need us according your spcification to produce the Knife Gate Valve .
Need, please e-mail to valve401@gmail.com
Now the standard technical requirements described below:
1 Pressure - temperature degree-level
Multifunctional Pump Control Valve Pressure - temperature rating from the shell, inner parts and control of materials management system, the pressure - temperature rating determined. Multifunctional Pump Control Valve at a temperature of the maximum allowable working pressure to take the shell, internal parts and control tube system materials in the temperature value of the maximum allowable working pressure in the small value.
1.1 The iron shell pressure - temperature rating should be consistent with GB/T17241.7 requirements.
1.2 steel shell of the pressure - temperature rating should be consistent with GB/T9124 requirements.
1.3 For the GB/T17241.7, GB/T9124 does not provide the pressure - temperature rating of the material, according to the relevant standards or design requirements.
2 Body
2.1 Body Flange
Flange shall be cast with the body as a whole. Iron flange type and dimensions should be consistent with the provisions of GB/T17241.6 technical conditions should be consistent GB/T17241.7 requirements; steel flange type and dimensions should be consistent with the provisions of GB/T9113.1 and technological conditions should be consistent with GB/T9124 requirements.
2.2 The length of the valve structure.
2.3 The minimum wall thickness of valve
The minimum wall thickness of cast iron valve body GB/T13932-1992 Table 3 should be consistent with the provisions of the minimum wall thickness of steel body parts should be consistent with the provisions of JB/T8937-1999 Table 1.
3 piece tectorial membrane valve seat
3.1 valve cover and the diaphragm seat, diaphragm valve seat and the connection type should be used flange.
3.2 diaphragm and valve seat shall not be less than the number of connecting bolts 4.
3.3 valve cover and the diaphragm seat a minimum wall thickness according to the requirements of 2.3.
3.4 valve cover flange and the diaphragm seat should be rounded. Flange sealing surface of the planar pattern can be used, sudden surface-type or concave-convex type.
4 Stem, slow-closing valve plate, the main valve plate | MechNet | welcome to visit the China National Machinery network of experts www.MechNet.com.cn
4.1 slow-closing valve plate and valve stem should be connected fastening and reliable.
4.2 slow-closing valve plate with the main valve plate sealing type metal seal pattern should be used.
4.3 The main valve plate and valve stem must slide a flexible and reliable.
4.4 the main valve plate and the main valve seat seal plate can be used two kinds of metal sealing and non-metallic sealing type.
5 Diaphragm
5.1 patch performance should conform to Table 2 (see next page) requirements. | MechNet | welcome to visit the China National Machinery network of experts www.MechNet.com.cn
5.2 Diaphragm appearance quality should be consistent with HG/T3090 requirements.
5.3 when applied to drinking water, the diaphragm material should be consistent with GB/T17219 security requirements.
6 Control Management Information System
Control systems control the various components should be able to withstand the maximum working pressure valve, the parts can not leak.
7 Materials
7.1 The main parts of the selection of appropriate materials, according to JB/T5300 requirements.
7.2 Copper alloy castings shall comply with the provisions of GB/T12225; GB/T12226 gray iron castings shall comply with the provisions of its tensile strength shall be not less than 200MPa; ductile iron castings shall comply with the provisions of GB/T12227; carbon steel castings shall comply with GB/T12229 requirements; GB/T12230 austenitic steel castings shall comply with requirements.
7.3 Multifunctional Pump Control Valve Steel Casting JB/T7927 appearance quality should meet the provisions of multifunctional pump control valve cast iron appearance quality reference JB/T7927 requirements.
8 shell strength
Multifunctional Pump Control Valve shell strength should be consistent with GB/T13927 requirements.
9 sealing performance
Multifunctional pump control valve sealing performance should be consistent with GB/T13927 requirements.
10 Cleanliness
Multifunctional Pump Control Valve JB/T7748 cleanliness should meet the requirements.
11 Painting
When applied to drinking water, the multifunctional pump control valve cavity coating material should be consistent with GB/T17219 security requirements. Outer surface of the coating is not provided for, the special requirements specified in the order in the contract. ball valve Trunnion Mounted Ball Valve Floating Ball Valve Top Entry Ball Valve Three way ball valve V Type Ball Valve
We can offer more Knife Gate Valve Information.If you need us according your spcification to produce the Knife Gate Valve .
Need, please e-mail to valve401@gmail.com
What are the common valve failure?
1, packing leak letter
This is a running, take, dripping, leaking main areas, in factories often seen.
Produced stuffing leaking because of the following points:
① filler and work of the corrosive medium, temperature, pressure, incompatible; ② filling wrong way, especially on the whole circle into the root filling, the most easy to produce leakage; ③ stem or surface finish machining accuracy is not enough, or have an oval degrees, or a notch; ④ stem pitting has occurred, or the lack of protection due to open rust; ⑤ stem bending; ⑥ filling materials used for too long, have become obsolete; ⑦ operating too fast.
Eliminating packing leakage is: ① the correct selection of filler; ② the proper conduct of filling; ③ stem processing failed, to repair or replace, the surface finish to achieve a minimum � 5, more important, to achieve � 8 above, and no other defects; ④ to take protective measures to prevent corrosion, has corroded to be replaced; ⑤ stem bending to straightening or update; ⑥ filling materials used by a certain time, to be replaced; ⑦ operator should pay attention to steady, slow to open slowly off, to prevent drastic changes in temperature or medium impact.
2, close the piece leak
Usually called the leak leak stuffing to close the piece is called in to vent. Off pieces of leakage, the valve inside, not easy to find.
Off pieces of leakage, can be divided into two categories: one is sealing surface leakage, the other is the root of leaking seals.
Caused by leakage of reasons: ① poorly sealing surface grinding; ② seal with the valve seat, valve flaps do not meet the stringent; ③ flap valve connected with the stem is not strong *; ④ stem bending and torsion, so that the upper and lower off pieces of misalignment ; ⑤ off too fast, bad, or had contact with sealing surface damage; ⑥ choice of materials properly, unable to withstand the corrosive medium; ⑦ will be cut-off valve, gate valve for regulating the use of. Sealing surface being unable to withstand the assault of high-speed flow of medium; ⑧ certain media, a gradual cooling in the valve closed, so that there slit sealing surface, there would be erosion phenomena; ⑨ some sealing surface and the valve seat, valve flap between the use of threaded connections, easy to produce oxygen concentration cell corrosion loose; ⑩ because of welding slag, rust, dust and other impurities embedded in, or production system has mechanical parts off block valve core, so that the valve could not close Yan.
Precautionary approach are:
① pressure test prior to use must be carefully leak testing and found that the root ring sealing surface spills or leaks, properly handle and then use; ② To check beforehand whether the various components of the valve intact, can not use the stem bending and torsion or valve flap and valve connection is not * the valve rod; ③ valve is crucial to stability strong, and not to Meng Jin, if found good contact between the sealing surface obstruct or block should be immediately opened a little bit, so that debris flow, and then carefully closed tightly; ④ selection valve, not only to consider the body's resistance to corrosion, but also to consider closing parts of the resistance to corrosion; ⑤ accordance with the structural characteristics of the valve, the proper use of the components necessary to readjust the flow control valve should be used; ⑥ for After the medium cooled off valve and a larger temperature difference between the situation, to cool and then look at the valve tightly closed; ⑦ seat, the valve flap and seal with screw connection, you can use Teflon tape for threaded between the filler, so there is no gap; ⑧ likely to fall into the impurities of the valve, the valve should be added before the filter.
3, stem lift failure
Stem lift failure reasons: ① operate too fast to thread damage; ② a lack of lubrication or lubricant failure; ③ stem bending and torsion; ④ surface finish is not enough; ⑤ tolerances allowed, gets the tight; ⑥ stem nut tilt; ⑦ improper choice of materials, such as the stem and stem nut for the same material, easy to bite; ⑧ thread is medium corrosion (refer to the dark bar at the bottom of the valve or the valve stem nut); ⑨ lack of protection for open-air valve , stem thread covered with dust and sand, or being corroded by frost and rain.
Prevention methods:
① meticulous operation, closed, not to Meng Jin, Do not turn to top dead center, open-hand wheel will be enough to reverse a couple of laps, so that screw on the side close together so as to avoid the impact of media to promote stem upward; ② regular checks of lubrication conditions, to maintain normal lubrication; ③ Do not use a long lever opening and closing valves, the workers used to a short lever to strictly control the force measured, to prevent torsional bending stem (referring to the hand wheel and stem directly connected to the valve); ④ increase processing or repair quality, and meet regulatory requirements; ⑤ corrosion-resistant materials to meet the working temperature and other working conditions; ⑥ stem and stem nut not to use the same material; ⑦ plastic to make stem nut, make checking intensity can not be only considered a good corrosion resistance and friction coefficient is small, must consider the intensity of the problem, the intensity is not enough, do not use; ⑧ open the valve stem to increase the protection cover; ⑨ normally open valve handwheel should be on a regular basis in order to avoid stem rust live.
4, other
Washer leak: The main reason is impatience corrosion is not suitable for working temperature and working pressure; there is high temperature valves. Prevention Methods: The working conditions compatible with the gasket on the new valve to check the suitability of gasket material, such as unsuitable to be replaced. For the high-temperature valve, to use it again another tight bolts.
Body cracking: General frozen making. Cold weather, the valve must be accompanied by thermal insulation measures, otherwise the valve should be halted and the connecting pipe clean water in the row (if any valve at the end of wire blocking, open wire blocking drainage).
Hand wheel damage: impact due to operation or long-lever vigorously. As long as operators and other relevant officers that could have been avoided.
Packing Gland Rupture: when pressed fill uneven force, or gland (usually cast iron) was flawed. Pressed fillers, to symmetrically rotating screws, non-skew. The time of manufacture not only pay attention to large and critical parts and pay attention to the Class of gland elements, or affect the use.
Stem and the valve plate connections failed: valve using stem rectangular head and the damper in the form of T-shaped slot to connect more, T-shaped slots are not always processed, thus allowing stem rectangular head wear faster. Mainly from manufacturing to resolve. However, units can also use the T-shaped slot to fill processing, it has a certain degree of finish.
Shuangzha pressure plate of the valve gate can not close the cover: Shuangzha plate tension is * generated by the top wedge, some valve, the top wedge material poor (low-grade cast iron), using the soon wear or break. The top wedge is a small pieces of materials used much, and use their own can be carbon steel production, replaced the original cast iron pieces. ball valve Trunnion Mounted Ball Valve Floating Ball Valve Top Entry Ball Valve ball valve V Type Ball Valve
We can offer more Knife Gate Valve Information.If you need us according your spcification to produce the Knife Gate Valve .
Need, please e-mail to valve401@gmail.com
This is a running, take, dripping, leaking main areas, in factories often seen.
Produced stuffing leaking because of the following points:
① filler and work of the corrosive medium, temperature, pressure, incompatible; ② filling wrong way, especially on the whole circle into the root filling, the most easy to produce leakage; ③ stem or surface finish machining accuracy is not enough, or have an oval degrees, or a notch; ④ stem pitting has occurred, or the lack of protection due to open rust; ⑤ stem bending; ⑥ filling materials used for too long, have become obsolete; ⑦ operating too fast.
Eliminating packing leakage is: ① the correct selection of filler; ② the proper conduct of filling; ③ stem processing failed, to repair or replace, the surface finish to achieve a minimum � 5, more important, to achieve � 8 above, and no other defects; ④ to take protective measures to prevent corrosion, has corroded to be replaced; ⑤ stem bending to straightening or update; ⑥ filling materials used by a certain time, to be replaced; ⑦ operator should pay attention to steady, slow to open slowly off, to prevent drastic changes in temperature or medium impact.
2, close the piece leak
Usually called the leak leak stuffing to close the piece is called in to vent. Off pieces of leakage, the valve inside, not easy to find.
Off pieces of leakage, can be divided into two categories: one is sealing surface leakage, the other is the root of leaking seals.
Caused by leakage of reasons: ① poorly sealing surface grinding; ② seal with the valve seat, valve flaps do not meet the stringent; ③ flap valve connected with the stem is not strong *; ④ stem bending and torsion, so that the upper and lower off pieces of misalignment ; ⑤ off too fast, bad, or had contact with sealing surface damage; ⑥ choice of materials properly, unable to withstand the corrosive medium; ⑦ will be cut-off valve, gate valve for regulating the use of. Sealing surface being unable to withstand the assault of high-speed flow of medium; ⑧ certain media, a gradual cooling in the valve closed, so that there slit sealing surface, there would be erosion phenomena; ⑨ some sealing surface and the valve seat, valve flap between the use of threaded connections, easy to produce oxygen concentration cell corrosion loose; ⑩ because of welding slag, rust, dust and other impurities embedded in, or production system has mechanical parts off block valve core, so that the valve could not close Yan.
Precautionary approach are:
① pressure test prior to use must be carefully leak testing and found that the root ring sealing surface spills or leaks, properly handle and then use; ② To check beforehand whether the various components of the valve intact, can not use the stem bending and torsion or valve flap and valve connection is not * the valve rod; ③ valve is crucial to stability strong, and not to Meng Jin, if found good contact between the sealing surface obstruct or block should be immediately opened a little bit, so that debris flow, and then carefully closed tightly; ④ selection valve, not only to consider the body's resistance to corrosion, but also to consider closing parts of the resistance to corrosion; ⑤ accordance with the structural characteristics of the valve, the proper use of the components necessary to readjust the flow control valve should be used; ⑥ for After the medium cooled off valve and a larger temperature difference between the situation, to cool and then look at the valve tightly closed; ⑦ seat, the valve flap and seal with screw connection, you can use Teflon tape for threaded between the filler, so there is no gap; ⑧ likely to fall into the impurities of the valve, the valve should be added before the filter.
3, stem lift failure
Stem lift failure reasons: ① operate too fast to thread damage; ② a lack of lubrication or lubricant failure; ③ stem bending and torsion; ④ surface finish is not enough; ⑤ tolerances allowed, gets the tight; ⑥ stem nut tilt; ⑦ improper choice of materials, such as the stem and stem nut for the same material, easy to bite; ⑧ thread is medium corrosion (refer to the dark bar at the bottom of the valve or the valve stem nut); ⑨ lack of protection for open-air valve , stem thread covered with dust and sand, or being corroded by frost and rain.
Prevention methods:
① meticulous operation, closed, not to Meng Jin, Do not turn to top dead center, open-hand wheel will be enough to reverse a couple of laps, so that screw on the side close together so as to avoid the impact of media to promote stem upward; ② regular checks of lubrication conditions, to maintain normal lubrication; ③ Do not use a long lever opening and closing valves, the workers used to a short lever to strictly control the force measured, to prevent torsional bending stem (referring to the hand wheel and stem directly connected to the valve); ④ increase processing or repair quality, and meet regulatory requirements; ⑤ corrosion-resistant materials to meet the working temperature and other working conditions; ⑥ stem and stem nut not to use the same material; ⑦ plastic to make stem nut, make checking intensity can not be only considered a good corrosion resistance and friction coefficient is small, must consider the intensity of the problem, the intensity is not enough, do not use; ⑧ open the valve stem to increase the protection cover; ⑨ normally open valve handwheel should be on a regular basis in order to avoid stem rust live.
4, other
Washer leak: The main reason is impatience corrosion is not suitable for working temperature and working pressure; there is high temperature valves. Prevention Methods: The working conditions compatible with the gasket on the new valve to check the suitability of gasket material, such as unsuitable to be replaced. For the high-temperature valve, to use it again another tight bolts.
Body cracking: General frozen making. Cold weather, the valve must be accompanied by thermal insulation measures, otherwise the valve should be halted and the connecting pipe clean water in the row (if any valve at the end of wire blocking, open wire blocking drainage).
Hand wheel damage: impact due to operation or long-lever vigorously. As long as operators and other relevant officers that could have been avoided.
Packing Gland Rupture: when pressed fill uneven force, or gland (usually cast iron) was flawed. Pressed fillers, to symmetrically rotating screws, non-skew. The time of manufacture not only pay attention to large and critical parts and pay attention to the Class of gland elements, or affect the use.
Stem and the valve plate connections failed: valve using stem rectangular head and the damper in the form of T-shaped slot to connect more, T-shaped slots are not always processed, thus allowing stem rectangular head wear faster. Mainly from manufacturing to resolve. However, units can also use the T-shaped slot to fill processing, it has a certain degree of finish.
Shuangzha pressure plate of the valve gate can not close the cover: Shuangzha plate tension is * generated by the top wedge, some valve, the top wedge material poor (low-grade cast iron), using the soon wear or break. The top wedge is a small pieces of materials used much, and use their own can be carbon steel production, replaced the original cast iron pieces. ball valve Trunnion Mounted Ball Valve Floating Ball Valve Top Entry Ball Valve ball valve V Type Ball Valve
We can offer more Knife Gate Valve Information.If you need us according your spcification to produce the Knife Gate Valve .
Need, please e-mail to valve401@gmail.com
Common valve of heating engineering
Many different types of valves, using a wide range. Sometimes it is in the pipeline is the main device for control purposes; Sometimes it is a secondary device, play a supporting role. If used improperly, we will have "run the risk, dripping, and drain" phenomenon, light those affecting the production, in serious cases lead to accidents. Therefore, understanding and correct use of the valve is a very important issue.
1, valve Categories
In the heating system, use the valve there are many. Such as gate valve, globe valve, ball valve, butterfly valve, check valve, safety valve, regulating valve, balance valve, Self-balancing valve and so on. The following elaborate.
1.1 Gate
Also known as gate valve, gate valve, is widely used as a valve.
How it works: gate valve seat sealing surface with a high degree of sealing surface clean, smooth, consistent, processed into a fit, tight seal pair. Gate through the upper valve stem put down pressure on the media to form turn-on and turn-off. It is played in the pipeline shutdown role.
Benefits: fluid resistance is small; full-time sealing surface from erosion; can be a two-way flow of media use, there is no direction; strong and durable; is not only suitable for small valves, and can be bigger valves.
Disadvantages: high large; open and close a long time; heavy; repair is difficult; if it is large-diameter valve, manual operation is relatively more laborious.
Valve stem according to the different distinct rod and dark rod; by gate construct different sub-parallel and wedge-type; there is a single gate, Shuangzha divided board. Heating engineering, commonly used in the Ming-style single-pole wedge gate valve (Z41H-16C) and dark pole wedge single-gate valve (Z45T-10), the former station installed on the primary side of heat, which is loaded thermal stations in the secondary side. It generally play two roles: as a master switch from the role; as an auxiliary equipment for maintenance before and after the main device used.
Valve installation, not to hand wheel in a horizontal line below (flip), otherwise it would be medium in the long-term retention in the valve cover, easy to stem erosion. In the heat supply project, the gate was once the main force of the valve. Now, with the widespread adoption of butterfly valves, gate valve butterfly valve has been replaced.
1.2 cut-off valve
Is also widely used as a valve. General caliber of 100 mm below. It works closely with the gate, but shut down parts (flap valve) the valve seat along the center line of movement. It is played in the pipeline shutdown, and may regulate flow of crude.
Advantages: create easy, easy maintenance, strong and durable.
Disadvantages: only allows one-way media flow direction when installing. Flow resistance big, bad seal.
Points according to different structures of straight-through type, rectangular type, DC type, balanced. Projects generally used straight-through flange (J41H) and internal thread straight through processing (J11H). Directional valve can not be under the anti-. We should not down-an.
In our production, life, in the past used straight-through processing, small-diameter cut-off valve, ball valve is now gradually being replaced.
1.3 Ball
Compared with gate valve, globe valve, ball valve is a kind of new, increasingly widely used valve. It works are: valve core cavity for a ball pass through the control spool valve stem for 90 ° rotation, so that the valve flow or occlusion. It is played in the pipeline shutdown role.
Benefits: In addition to a gate valve, globe valve advantages, there are small, sealed good (zero leakage), the advantages of easy to operate. Currently in the petrochemical, electric power, nuclear power, aviation and aerospace sectors such as widely used.
Disadvantages: repairs difficult.
Valve has two forms: floating ball and fixed ball type. In the heating project, a number of key positions, such as the important branch of the then population of thermal stations, DN250 below, often imported ball. Domestic ball with a different structure: Domestic valve in the valve body is generally two type, 3 type, flange connection;, while import valve in the valve body are one type, welded connections, less the point of failure. It is the Nordic country of origin, such as Finland, Denmark, heating technology, the more developed countries. Such as Finland, NAVAL, VEXVE, Denmark DAFOSS so. Because of its excellent sealing and operating reliability, long popular users of all ages. No directional valve can be installed at any angle. The level of welding ball valve installation, the valve must be open, to avoid the welding of the EDM hurt ball surface; When the vertical pipe installed, if the welding on the interface, the valve must be opened, if soldering the next interface, the valve must be closed in order to avoid valve internally heat burns.
1.4 Butterfly
In the heating system, is currently the most widely used, type is also up to a valve.
How it works: valve flap is a disc, through the stem rotation, valve flap in the seat for 90 ℃ within the rotation, to achieve the valve switch. It is played in the pipeline shutdown role.
Advantages: simple structure, is lightweight, easy to operate and good sealing.
Disadvantages: full-time, valve plate (seal) by the media erosion.
In the heating project, there are three eccentric butterfly valves used metal sealing butterfly valve, rubber soft sealing butterfly valve.
1.5 Check Valve
Also known as check valve, single-stream door. Play a supporting role of a common valve.
How it works: to rely on its own strength as well as the fluid valve weight valve, automatic open and close the valve. As the name suggests, its role is to prevent the media back. Usually installed in the pump exit to prevent water hammer damage to the pump.
Heating projects are commonly used in the level of lift (H41H), Rosa xanthina Swing (H44H), double valve butterfly (H77H).
Directional valve, absolutely can not hold against. Different forms of check valve, according to their structure, have a fixed installation, must not be installed wrong. The level of lift can only be installed in a horizontal tube on the road, and ensure the valve flap in a vertical state; Rosa xanthina Swing can only be installed in a horizontal tube on the road, and ensure the valve flap shaft at the level of state; pairs of butterfly valve can be any installation.
1.6 Control Valve
Also called the throttle. Secondary heating system is a network of commonly used valves.
How it works: form, structure and similar cut-off valve. Sealing is only different from control valve valve seat valve and vacuum bottle like a cork and the bottle, through the valve flap movement changed to regulate the traffic flow area. In the valve axis, said there is a corresponding flow of the ruler.
Role: regulating pipe flow distribution between the media in order to achieve thermal equilibrium.
Heating projects have been using a straight-through (T41H), but it has some drawbacks: large flow resistance, not vertical installation. So as technology advances, balancing valve (PH45F) instead of the control valve.
1.7 Valves
Improved control valve. Flow channel using DC type, PTFE valve seat changed;
Overcome the shortcomings of a large flow resistance, while two additional advantages: seal more reasonable, both cut-off function.
Heating project in the second-line use of thermal stations, with excellent flow regulating characteristics, especially suitable for variable flow systems.
Directional and can be installed level can also be installed vertically.
1.8 Self-balancing valve
Also known as flow control valves. Its working principle is: there is a valve spring and the rubber membrane formed by the body, it is connected with the stem. If the flow rate increases, would generate an unbalanced force on it, making valve flap to close the move to reduce the flow area, reduce traffic, so that return flow settings. And vice versa. After the flow of this valve has always been to maintain the same, to control flow purposes.
Installed in the heating system, hot people, the branch point. Automatic elimination of hydraulic imbalance, improve system performance and achieve economic operation. Self-balancing valve directional, do not install anti-.
In addition, there is the use of environment on corrosion and protection of valve problems, media on the valve's internal corrosion and protection problems, temperature and pressure sealing and leakage problems and so on. In short, the valve is small, learning a great, yet we go to continuous learning summary.
ball valve Trunnion Mounted Ball Valve Floating Ball Valve Top Entry Ball Valve ball valve V Type Ball Valve
We can offer more Knife Gate Valve Information.If you need us according your spcification to produce the Knife Gate Valve .
Need, please e-mail to valve401@gmail.com
Saturday, September 18, 2010
numerical simulation technology
Finite element analysis using the numerical simulation technology as a secondary pipeline ball valve design is necessary for the complex stress state, the complex process of welding technology for the design and optimization of welding process to provide a strong argument, the following parts of the design and manufacture can be Numerical simulation:
1, split body ball valve and connecting pipe stress analysis of bolt;
2, the whole pipeline welding ball valve body valve stress analysis;
3, the whole body welding process of welding temperature field distribution, the distribution of welding residual stress, welding axial deformation and radial deformation prediction, in Figure (11) below;
(A) axial deformation of the valve (b) radial deformation of the valve
Figure (k) the inherent strain method of welding deformation
4, the welding process on the support plate by the impact of state power, in Figure (12) below;
Figure (12) stress distribution of support board
5, the deformation of spherical projections, particularly for large diameter, high-pressure-level force in the media sphere that may occur under the deformation, such deformation should be controlled in the processing of roundness tolerance, Figure (13) below;
Figure (13) rated sphere elastic deformation under pressure
6, full-strength analysis of welded ball valve body, Figure (14) below;
(A) tube-type valves welded intensity (b) welded ball valves like intensity
Figure (14) Strength analysis of valve
7, the whole ball of welding the upper and lower body structure supported by the bending moment and torque bearing composite load should be stress analysis;
8, torque transmission system design failure analysis and fault;
9, ball valve gate for the rapid (<0.5 seconds) of the dynamic stress analysis of shaft; valve ball valve gate valve check valve globe valve butterfly valve
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1, split body ball valve and connecting pipe stress analysis of bolt;
2, the whole pipeline welding ball valve body valve stress analysis;
3, the whole body welding process of welding temperature field distribution, the distribution of welding residual stress, welding axial deformation and radial deformation prediction, in Figure (11) below;
(A) axial deformation of the valve (b) radial deformation of the valve
Figure (k) the inherent strain method of welding deformation
4, the welding process on the support plate by the impact of state power, in Figure (12) below;
Figure (12) stress distribution of support board
5, the deformation of spherical projections, particularly for large diameter, high-pressure-level force in the media sphere that may occur under the deformation, such deformation should be controlled in the processing of roundness tolerance, Figure (13) below;
Figure (13) rated sphere elastic deformation under pressure
6, full-strength analysis of welded ball valve body, Figure (14) below;
(A) tube-type valves welded intensity (b) welded ball valves like intensity
Figure (14) Strength analysis of valve
7, the whole ball of welding the upper and lower body structure supported by the bending moment and torque bearing composite load should be stress analysis;
8, torque transmission system design failure analysis and fault;
9, ball valve gate for the rapid (<0.5 seconds) of the dynamic stress analysis of shaft; valve ball valve gate valve check valve globe valve butterfly valve
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Need, please e-mail to valve401@gmail.com
Experts teach you how to properly use the valve (Part Two)
Metal sealed valves generally higher than those elastic sealing valve long life, but it is difficult to achieve completely sealed. Metal seal can adapt to a higher operating temperature, flexible seal is affected by temperature limit has flaws.
If you require the use of flow control valve as the main choice is the right size and type of valve. Butterfly structure principle is particularly suitable for production of large-diameter valves. Butterfly not only in oil, gas, chemicals, water treatment, etc. are widely used in general industry, but also applied to thermal power plant cooling water systems.
Commonly used in butterfly valves are wafer type butterfly valve and flange type butterfly valve two kinds. Right clip-on butterfly is double-headed bolts to connect the valve between the two pipe flanges, flange type butterfly valve is a valve with a flange on, with bolts at both ends of the valve on the pipe flange connection method Lan on.
Evolved from the stopcock valve. It has the same movement rotated 90 degrees to mention only difference is that cock body is a sphere, a circular through-hole or channel through its axis. The sphere and the ratio of openings should be such that when the ball rotated 90 degrees, in the import and export of office should be fully rendered sphere, thus cutting off the flow.
Just use the rotary valve 90-degree rotation of the operation and a small torque can be closed tightly. The body cavity of full equality for the media to provide a little resistance, through the flow channel. Generally considered the most suitable valve opening and closing done directly used, but the recent development has been designed to give it a throttle valve and control the flow purposes. The main features of valve is its own compact, easy operation and maintenance for water, solvents, acids, and natural gas work in general media, but also applies to poor working conditions of media, such as oxygen, hydrogen peroxide, methane and ethylene and so on. Ball valve can be integral, it can be modular.
Selection of valves to prevent backflow by media
This type of valve is the role of media in one direction only allows movement, but also to prevent the direction of flow. Usually the valve is automatically work, the fluid flow in one direction under pressure, valve flap open; fluid flow in the opposite direction from the fluid pressure and valve flap valve flap from the coincidence of acting on the valve seat and thus cut off the flow. Check them belonging to this type of valve, which includes Swing check valve and lift check valve. Swing Check Valve with ordinary hinge, there is a door the same as the free flap valve leaning tilt seat surface. In order to ensure that the flap valve seat face every time to reach a suitable position, the valve flap design in the hinge body to valve flap has enough to swing space, and make a real flap valve, comprehensive engagement with the valve seat. Valve flap can all be made of metal can also be embedded in the metal on leather, rubber, or synthetic coverage, depending on the use of performance requirements. Swing check valve in the fully open position, the fluid pressure virtually unimpeded, so the pressure drop through the valve is relatively small. Check the valve lift valve is located in the valve body on the valve seat sealing surface. In addition to this valve flap valve is free to lift, the other part of the same as the cut-off valve, the fluid pressure valve from the valve seat sealing surface of valve lift, medium return valve flap led to a seat on the back, and cut off the flow. According to conditions of use, the valve flap can be all-metal structure can also be rack mounted in the valve flap rubber mat or rubber ring form. The same as the cut-off valves, fluid channels through the lift valve is narrow, so that by elevating the pressure drop valve Swing check valve than the bigger, and the flow of Swing Check Valve restrictions on rarely.
Medium parameters chosen by regulating valve
In the production process, in order to make media pressure, flow and other parameters meet the process requirements, need to install the adjusting mechanism to adjust these parameters. Regulating the organization's main working principle is to change the valve by valve flap and valve seat between the flap and the circulation area, to achieve the purpose of regulating the above parameters. Such valves are referred to as control valves, which are divided into relying on power-driven media itself is called self-drive-type control valve such as valves, regulator valve, all leading up power-driven (such as electricity, compressed air and fluid power) as he was driving control valve, such as the electric control valve, pneumatic control valve and hydraulic control valve and so on.
ball valve Trunnion Mounted Ball Valve Floating Ball Valve Top Entry Ball Valve Three way ball valve V Type Ball Valve
We can offer more Knife Gate Valve Information.If you need us according your spcification to produce the Knife Gate Valve .
Need, please e-mail to valve401@gmail.com
If you require the use of flow control valve as the main choice is the right size and type of valve. Butterfly structure principle is particularly suitable for production of large-diameter valves. Butterfly not only in oil, gas, chemicals, water treatment, etc. are widely used in general industry, but also applied to thermal power plant cooling water systems.
Commonly used in butterfly valves are wafer type butterfly valve and flange type butterfly valve two kinds. Right clip-on butterfly is double-headed bolts to connect the valve between the two pipe flanges, flange type butterfly valve is a valve with a flange on, with bolts at both ends of the valve on the pipe flange connection method Lan on.
Evolved from the stopcock valve. It has the same movement rotated 90 degrees to mention only difference is that cock body is a sphere, a circular through-hole or channel through its axis. The sphere and the ratio of openings should be such that when the ball rotated 90 degrees, in the import and export of office should be fully rendered sphere, thus cutting off the flow.
Just use the rotary valve 90-degree rotation of the operation and a small torque can be closed tightly. The body cavity of full equality for the media to provide a little resistance, through the flow channel. Generally considered the most suitable valve opening and closing done directly used, but the recent development has been designed to give it a throttle valve and control the flow purposes. The main features of valve is its own compact, easy operation and maintenance for water, solvents, acids, and natural gas work in general media, but also applies to poor working conditions of media, such as oxygen, hydrogen peroxide, methane and ethylene and so on. Ball valve can be integral, it can be modular.
Selection of valves to prevent backflow by media
This type of valve is the role of media in one direction only allows movement, but also to prevent the direction of flow. Usually the valve is automatically work, the fluid flow in one direction under pressure, valve flap open; fluid flow in the opposite direction from the fluid pressure and valve flap valve flap from the coincidence of acting on the valve seat and thus cut off the flow. Check them belonging to this type of valve, which includes Swing check valve and lift check valve. Swing Check Valve with ordinary hinge, there is a door the same as the free flap valve leaning tilt seat surface. In order to ensure that the flap valve seat face every time to reach a suitable position, the valve flap design in the hinge body to valve flap has enough to swing space, and make a real flap valve, comprehensive engagement with the valve seat. Valve flap can all be made of metal can also be embedded in the metal on leather, rubber, or synthetic coverage, depending on the use of performance requirements. Swing check valve in the fully open position, the fluid pressure virtually unimpeded, so the pressure drop through the valve is relatively small. Check the valve lift valve is located in the valve body on the valve seat sealing surface. In addition to this valve flap valve is free to lift, the other part of the same as the cut-off valve, the fluid pressure valve from the valve seat sealing surface of valve lift, medium return valve flap led to a seat on the back, and cut off the flow. According to conditions of use, the valve flap can be all-metal structure can also be rack mounted in the valve flap rubber mat or rubber ring form. The same as the cut-off valves, fluid channels through the lift valve is narrow, so that by elevating the pressure drop valve Swing check valve than the bigger, and the flow of Swing Check Valve restrictions on rarely.
Medium parameters chosen by regulating valve
In the production process, in order to make media pressure, flow and other parameters meet the process requirements, need to install the adjusting mechanism to adjust these parameters. Regulating the organization's main working principle is to change the valve by valve flap and valve seat between the flap and the circulation area, to achieve the purpose of regulating the above parameters. Such valves are referred to as control valves, which are divided into relying on power-driven media itself is called self-drive-type control valve such as valves, regulator valve, all leading up power-driven (such as electricity, compressed air and fluid power) as he was driving control valve, such as the electric control valve, pneumatic control valve and hydraulic control valve and so on.
ball valve Trunnion Mounted Ball Valve Floating Ball Valve Top Entry Ball Valve Three way ball valve V Type Ball Valve
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Need, please e-mail to valve401@gmail.com
HPLC 6-way valve injector use and maintenance instructions
Six-way valve injector is a high performance liquid chromatography system, the ideal injector, which is sealed by a circular pad (rotor) and fixed-base (stator) component. The U.S. company's six-way Rheodyne valve injector of the most common, major manufacturers of HPLC instruments are this product as the instrument into the injector.
How it works:
1, handle-bit sample (Load) position, samples were micro-injection needle from the injection hole injection into the quantitative aspect of quantitative ring filled, the excess sample from the exhaust venting holes;
2, will rotate the handle to the injection (Inject) position, the valve connected with the liquid flow path from the pump delivered the mobile phase washed quantitative aspect of promoting the liquid sample into the analytical column for analysis.
Although the six-way valve injector with a simple structure, easy to use, long life, routine maintenance without the need characteristics, but the correct use and maintenance will be able to increase the service life and protect peripheral equipment, while increasing the analysis accuracy. If used properly, then the six-way valve injector generally continuous nebulization 30000 times without the need for maintenance.
The following six-way valve of the injector of the use and maintenance matters (for reference only)
1, the handle is between Load and Inject, due to a temporary blocking of the flow path, flow path in the pressure surge, and then go into the kind of place, high pressure caused damage to the stigma, it should be as soon as possible turn valves, can not be stay in the middle. In the HPLC system used syringe needles are different from gas chromatography, is a flat head injector. On the one hand, the outer needle injector sealing tube close to the inside, seal performance, no leakage, without introducing air; the other hand, it prevents a needle stab the bad seal components and stator.
2, the six-way valve into the sample injection device fitted methods are part of the solution method and full of liquid and French. France to use part of liquid into the sample, the sample size up to 75% of the volume of quantitative ring, such as the quantitative ring up 20gL sample 15p, L of the sample, and requires an accurate volume of each sample, the same; the use of fully loaded liquid sampling method when the sample size of at least quantitative ring size 3 to 5 times, that is, 20gL quantitative ring 60 to at least sample 1001aL samples, so as to completely replace the sample quantitative ring residual solution, to achieve the required precision degree and reproducibility. Recommended 100ul flat-head injection needle filled with 20ul sample loop.
3, injection volume according to the needs of their own making quantitative ring, generally does not require the accurate calculation of quantitative ring size, for example, a nominal 10gL quantitative ring, is actually 9gL or 1lgL not important, because the tested samples and calibration sample injection volume consistent errors in the calculation of the results have been offset.
4, injection sample particles and energy demands without resistance death of needles and injection valve material, the sample solution were to use 0.45 ~ tm of the membrane filter. To prevent particles blocking injection valve and reduce the wear and tear on injection valves. In order to prevent the buffer salts and other residual materials remain in the injection system, should be washed after each injection device, usually do not saline diluent, water or saline washing mobile phase, in the injection valve Load Inject position, and repeated washing, and then non-fiber paper to wipe the outside of syringe needles. ball valve Trunnion Mounted Ball Valve Floating Ball Valve Top Entry Ball Valve ball valve V Type Ball Valve
We can offer more Knife Gate Valve Information.If you need us according your spcification to produce the Knife Gate Valve .
Need, please e-mail to valve401@gmail.com
How it works:
1, handle-bit sample (Load) position, samples were micro-injection needle from the injection hole injection into the quantitative aspect of quantitative ring filled, the excess sample from the exhaust venting holes;
2, will rotate the handle to the injection (Inject) position, the valve connected with the liquid flow path from the pump delivered the mobile phase washed quantitative aspect of promoting the liquid sample into the analytical column for analysis.
Although the six-way valve injector with a simple structure, easy to use, long life, routine maintenance without the need characteristics, but the correct use and maintenance will be able to increase the service life and protect peripheral equipment, while increasing the analysis accuracy. If used properly, then the six-way valve injector generally continuous nebulization 30000 times without the need for maintenance.
The following six-way valve of the injector of the use and maintenance matters (for reference only)
1, the handle is between Load and Inject, due to a temporary blocking of the flow path, flow path in the pressure surge, and then go into the kind of place, high pressure caused damage to the stigma, it should be as soon as possible turn valves, can not be stay in the middle. In the HPLC system used syringe needles are different from gas chromatography, is a flat head injector. On the one hand, the outer needle injector sealing tube close to the inside, seal performance, no leakage, without introducing air; the other hand, it prevents a needle stab the bad seal components and stator.
2, the six-way valve into the sample injection device fitted methods are part of the solution method and full of liquid and French. France to use part of liquid into the sample, the sample size up to 75% of the volume of quantitative ring, such as the quantitative ring up 20gL sample 15p, L of the sample, and requires an accurate volume of each sample, the same; the use of fully loaded liquid sampling method when the sample size of at least quantitative ring size 3 to 5 times, that is, 20gL quantitative ring 60 to at least sample 1001aL samples, so as to completely replace the sample quantitative ring residual solution, to achieve the required precision degree and reproducibility. Recommended 100ul flat-head injection needle filled with 20ul sample loop.
3, injection volume according to the needs of their own making quantitative ring, generally does not require the accurate calculation of quantitative ring size, for example, a nominal 10gL quantitative ring, is actually 9gL or 1lgL not important, because the tested samples and calibration sample injection volume consistent errors in the calculation of the results have been offset.
4, injection sample particles and energy demands without resistance death of needles and injection valve material, the sample solution were to use 0.45 ~ tm of the membrane filter. To prevent particles blocking injection valve and reduce the wear and tear on injection valves. In order to prevent the buffer salts and other residual materials remain in the injection system, should be washed after each injection device, usually do not saline diluent, water or saline washing mobile phase, in the injection valve Load Inject position, and repeated washing, and then non-fiber paper to wipe the outside of syringe needles. ball valve Trunnion Mounted Ball Valve Floating Ball Valve Top Entry Ball Valve ball valve V Type Ball Valve
We can offer more Knife Gate Valve Information.If you need us according your spcification to produce the Knife Gate Valve .
Need, please e-mail to valve401@gmail.com
Wednesday, September 15, 2010
Bimetallic Steam Traps
Bimetallic steam trap is to trap heat in the structure of the static type of the most solid trap. Its advantages are: afraid of water hammer, high voltage, small size, light weight, not afraid of cold, can be automatically scheduled air, can be installed at any position; back-pressure rate of more than 80%.
The trap for the steam pipes in charge of Road, pipe network tracing, instrument tracing, life there are high-temperature heating and allow the condensation of water heating equipment hydrophobic, the use of a wide range.
Bimetallic steam trap is a bimetal temperature sensing element driving the valve core to switch the valve. When the device just starting when the low-temperature condensed water pipe occurs, double metal film is flat, the spool in the spring in the open position under the elastic. When the condensate water temperature gradually increased, bimetal temperature sensing element began to bend, and to heart valve into the closed position. In the condensate to saturation temperature before the trap completely shut down. Valve is always there before the high-temperature condensation of water, no steam leakage, energy-saving effect is good.
ball valve Trunnion Mounted Ball Valve Floating Ball Valve Top Entry Ball Valve ball valve V Type Ball Valve
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Need, please e-mail to valve401@gmail.com
The trap for the steam pipes in charge of Road, pipe network tracing, instrument tracing, life there are high-temperature heating and allow the condensation of water heating equipment hydrophobic, the use of a wide range.
Bimetallic steam trap is a bimetal temperature sensing element driving the valve core to switch the valve. When the device just starting when the low-temperature condensed water pipe occurs, double metal film is flat, the spool in the spring in the open position under the elastic. When the condensate water temperature gradually increased, bimetal temperature sensing element began to bend, and to heart valve into the closed position. In the condensate to saturation temperature before the trap completely shut down. Valve is always there before the high-temperature condensation of water, no steam leakage, energy-saving effect is good.
ball valve Trunnion Mounted Ball Valve Floating Ball Valve Top Entry Ball Valve ball valve V Type Ball Valve
We can offer more Knife Gate Valve Information.If you need us according your spcification to produce the Knife Gate Valve .
Need, please e-mail to valve401@gmail.com
Monday, September 13, 2010
DBB dual relief valve plug the dual-parameter
Model: DBB
Product diameter: DN15-DN300
Product pressure :1.0-6 .4 MPA
Product Material: 304,316,316 L
DBB double dual relief valve plug detail
DBB double plug for double relief valve: aviation kerosene, crude oil, light oil, natural gas, liquefied petroleum gas, pipeline gas, chemicals and other media channels, as the ideal medium cut-off device.
DBB dual relief valve plug double double blockage of the overall exhaust manifold for the primary isolation and is responsible for liquid or gas services. Designed to save weight and installation space, they can in a wide range of materials, sizes and combinations to the head unit to meet all requirements.
Connection:
1. Flange to flange
2, the flange of the screw
3, thread on thread ball valve Trunnion Mounted Ball Valve Floating Ball Valve Top Entry Ball Valve Three way ball valve V Type Ball Valve
We can offer more Knife Gate Valve Information.If you need us according your spcification to produce the Knife Gate Valve .
Need, please e-mail to valve401@gmail.com
Product diameter: DN15-DN300
Product pressure :1.0-6 .4 MPA
Product Material: 304,316,316 L
DBB double dual relief valve plug detail
DBB double plug for double relief valve: aviation kerosene, crude oil, light oil, natural gas, liquefied petroleum gas, pipeline gas, chemicals and other media channels, as the ideal medium cut-off device.
DBB dual relief valve plug double double blockage of the overall exhaust manifold for the primary isolation and is responsible for liquid or gas services. Designed to save weight and installation space, they can in a wide range of materials, sizes and combinations to the head unit to meet all requirements.
Connection:
1. Flange to flange
2, the flange of the screw
3, thread on thread ball valve Trunnion Mounted Ball Valve Floating Ball Valve Top Entry Ball Valve Three way ball valve V Type Ball Valve
We can offer more Knife Gate Valve Information.If you need us according your spcification to produce the Knife Gate Valve .
Need, please e-mail to valve401@gmail.com
Thursday, September 9, 2010
V-ball valve adjustment parameters
Model: Qv347H-16C Qv347Y-16P
Product Diameter: 40 ~ 1000mm
Product pressure: 1.6MPa
Product Material: stainless steel casting
Ball valve V-regulation details
◆ product use
Ball valve V-regulation as a result of the ball with the V-core structure, with the shearing of the valve seat. It is applied to paper making, chemical industry, metallurgical industry contains small solid particles or fibers of the suspension medium on the control of process parameters, especially for pulp, paper pulp production processes, white, black liquor , white liquid, such as suspended particles and the concentration of the fluid, turbid fluid medium paste the automatic adjustment
◆ Features
1, a flexible load to guarantee the pressure-assisted sealing seat and ball valve seat since the hard core in close contact to the end
2, with the overall style of the body structure, there is no possibility of leakage potential
3, the percentage with such characteristics, there is a wide range of control and stability control in particular, can be widely used in a variety of process
4, stem and ball core using involute spline connection, when the loaded tooth profile, the teeth have a radial force can play the role of auto-centering and uniformity of the teeth to force the high-intensity, long life
◆ Model performance parameters Qv347H-16C Qv347Y-16P
Working pressure (MPa) 1.6
The application of temperature (℃) -29 ~ 180 -29 ~ 425
Control the application of medium paper pulp, sewage, solid and with small solid particles
Steel casting steel casting stainless steel materials
Chromium stainless steel stem
Sealing surface of chromium carbide steel reactor
Flexible graphite packing ball valve Trunnion Mounted Ball Valve Floating Ball Valve Top Entry Ball Valve Three way ball valve V Type Ball Valve
We can offer more Knife Gate Valve Information.If you need us according your spcification to produce the Knife Gate Valve .
Need, please e-mail to valve401@gmail.com
Product Diameter: 40 ~ 1000mm
Product pressure: 1.6MPa
Product Material: stainless steel casting
Ball valve V-regulation details
◆ product use
Ball valve V-regulation as a result of the ball with the V-core structure, with the shearing of the valve seat. It is applied to paper making, chemical industry, metallurgical industry contains small solid particles or fibers of the suspension medium on the control of process parameters, especially for pulp, paper pulp production processes, white, black liquor , white liquid, such as suspended particles and the concentration of the fluid, turbid fluid medium paste the automatic adjustment
◆ Features
1, a flexible load to guarantee the pressure-assisted sealing seat and ball valve seat since the hard core in close contact to the end
2, with the overall style of the body structure, there is no possibility of leakage potential
3, the percentage with such characteristics, there is a wide range of control and stability control in particular, can be widely used in a variety of process
4, stem and ball core using involute spline connection, when the loaded tooth profile, the teeth have a radial force can play the role of auto-centering and uniformity of the teeth to force the high-intensity, long life
◆ Model performance parameters Qv347H-16C Qv347Y-16P
Working pressure (MPa) 1.6
The application of temperature (℃) -29 ~ 180 -29 ~ 425
Control the application of medium paper pulp, sewage, solid and with small solid particles
Steel casting steel casting stainless steel materials
Chromium stainless steel stem
Sealing surface of chromium carbide steel reactor
Flexible graphite packing ball valve Trunnion Mounted Ball Valve Floating Ball Valve Top Entry Ball Valve Three way ball valve V Type Ball Valve
We can offer more Knife Gate Valve Information.If you need us according your spcification to produce the Knife Gate Valve .
Need, please e-mail to valve401@gmail.com
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