Double Layer Roll Forming Machine
Double Layer Roll Forming Machine Double Layer Roll Forming Machine, Roof Sheet Forming Machine, Double Layer Sheet Roll Forming Machine, Iron Sheet Making Machine Botou Xianfa Roll Forming Machine Factory , https://www.rollforming.nl
This kind of machine make two types of tile together perfectly, it has reasonable structure, beautiful appearance, with advantage of saving space, easy operate and especially welcomed by the customer with limit area or site
Descriptions of Roll Forming Machine for Roof Panel, Wall Panel:
1.This kind of Cold Roll Forming Machine is widely used for making various metal wall panels and roof panels for steel constructions, steel structure projects and containment systems etc.
2. This production line consists of feeding unit, uncoiler, feeding guide, roll forming machine, cutter, automatic stacker, hydraulic system and electric control system.
3. The line speed of this panel forming machine is 40m/min.
Components of Roll Forming Machine for Roof Panel, Wall Panel:
1) Un-coiler:
Electric un-coiler, with coil-car
Load capacity = Max.10Tons;
2) Roll forming machine:
About 18steps to form;
Material of Roller: 45# steel with chromizing on surface
Voltage:380V/50Hz; Main line speed: 40m/min;
3) Hydraulic cutter:
1) Stop to cut, Post cut,
2) Cutting tool material: Cr12, Heat treatment
4) PLC control system:
Using Mitsubishi PLC Control the quantity, length automatically, LCD screen; remote control available.
Related Products:Roof Sheet Forming Machine,Iron Sheet Making Machine,double layer roof sheet roll forming machine.
Control valve common troubleshooting 60 method
Regulating valve common troubleshooting 60 method in industrial automation instruments, the control valve is heavy, coupled with the simple structure, often not valued by people. However, it is on the process pipeline and its working conditions are complex. Once problems arise, everyone is busy with it. Because of its bulky, hard to find the problem, often thankless, but also involves the system put into operation, the system is complete, adjust the quality, environmental pollution. First, the method of raising life expectancy (8 methods) 1) large opening work to extend the life-span method for the valve to start as far as possible in the maximum opening of work, such as 90%. In this way, cavitation, erosion and other damage occurred in the spool head. With the destruction of the valve, the flow increases, the corresponding valve and then off, so constantly damaged, and gradually closed, so that the entire valve fully utilize until the valve core and sealing surface damage, can not be used so far. At the same time, the opening of large opening throttle gap, erosion weakened, which than the beginning of the valve in the middle of the opening and a small opening work to improve life expectancy of 1 to 5 times. Such as a chemical plant using this method, valve life increased by 2 times. 2) S to increase the work to reduce the opening to increase the life-span method to reduce the S, that is, increase the system in addition to the loss of control valve to reduce the pressure drop assigned to the valve, in order to ensure that the flow through the control valve will inevitably increase the control valve Opening, at the same time, reducing the pressure drop on the valve, cavitation, erosion also weakened. The specific measures are: set the orifice plate after the valve to save consumption pressure drop; close the pipeline on the manual valve in series to the control valve to obtain a more ideal job opening so far. The valve at the beginning of a large opening in the small work, the use of this method is very simple, convenient and effective. 3) to reduce the diameter of the work to improve the life span method by reducing the diameter of the valve to increase the work of the opening, the specific methods are: ①for a smaller size of the valve, such as DN32 into DN25; ② valve body Do not change, replace the small seat diameter valve seat. As an overhaul of a chemical plant will be djl parts dgl0 replacement, life expectancy increased by 1 times. 4) The transfer of damage to the location to improve life expectancy to the place of serious damage to the secondary location to protect the valve seat sealing surface and throttling surface. 5) increase the throttle channel to increase life expectancy Increase the throttle channel is the simplest thickened valve seat, the valve seat hole growth, the formation of a longer throttle passage. On the one hand, it can delay the sudden expansion of the flow-closure type after the throttle, delay the transfer and destroy the position and keep it away from the sealing surface; on the other hand, increase the throttling resistance and reduce the recovery of the pressure, Erosion diminished. Some of the valve seat hole designed to step, wave-type, is to increase the resistance, weaken the cavitation. This method is often used when introducing high-pressure valves in devices and improving older valves and is also very effective. 6) to change the flow direction to improve life Open flow toward the open direction, cavitation, erosion mainly in the sealing surface, so that the valve core and valve seat sealing surface quickly suffered damage; flow closed toward the closed direction flow , Cavitation erosion role in the throttle after the valve seat sealing surface to protect the sealing surface and the valve root, extending the life. Used as open-flow valve, when the problem of extending life expectancy is more prominent, just change the flow direction can extend the life of 1 to 2 times. 7) Use of special materials to improve life expectancy France is anti-cavitation (damage to the shape of small honeycomb dot) and erosion (streamlined small groove), can be replaced by cavitation erosion and erosion of special materials to create throttling pieces. This special materials are 6YC-1, A4 steel, Secretary too Lai, cemented carbide. For anti-corrosion, can use more corrosion-resistant, and have certain mechanical properties, physical properties of the material. This material is divided into two types of non-metallic materials (such as rubber, PTFE, ceramics, etc.) and metal materials (such as Monel, Hastelloy, etc.). 8) to change the valve structure to improve life span method to change the valve structure or choose to have a longer life of the valve approach to achieve the purpose of improving life expectancy, such as the choice of multi-stage valve, anti-cavitation valve, corrosion-resistant valve. Second, the control valve often stuck or blocked anti-blocking (card) method (6 methods) 1) cleaning method pipeline slag, rust, slag and other restrictions in the throttle, the guide position, the lower valve cover balance hole Caused by blockage or stuck so that the valve surface, guide surface strain and scratches, sealing surface indentation and so on. This often occurs in the early delivery of new delivery systems and overhauls. This is the most common failure. In this case, you must uninstall the cleaning, remove the slag material, such as the sealing surface is also damaged should be ground at the same time the bottom plug to open to flush away from the balance hole into the valve cap slag material, and the pipeline Rinse. Put into operation before the valve is fully open, medium flow into the normal operation after a period of time. 2) External scouring method For some easily sedimentation, medium containing solid particles using ordinary valve adjustment, often in the throttle, the guide block, can be flush at the bottom of the valve cover flushing gas and steam. When the valve is clogged or stuck, open the external gas or steam valve, you can complete the flushing work in the case of the valve does not move, so that the valve normal operation. 3) The installation of pipe filter method on the small-caliber control valve, especially the ultra-small flow control valve, the throttle clearance is very small, medium can not have a little slag material. In this case of blockage, it is best to install a filter on the valve before the pipeline to ensure the smooth passage of media. Control valve with locator, locator is not working properly, the air passage choke plug is the most common failure. Therefore, with locator work, you must handle the gas source, the commonly used approach is to install the air filter regulator in front of the gas locator 4) Increase the throttle gap method such as the medium of solid particles or pipes Washes off the welding slag and rust, etc. due to over throttle can cause blockage, stuck and other failures, can be used to throttle large gap throttling pieces - throttle area for the window, the opening of the spool, sleeve Tubes, because of their concentrated throttle area rather than their circumferential distribution, can easily be ruled out. If it is single, two-seater valve plunger can be changed to "V" -shaped spool, or into the sleeve valve. For example, a chemical plant often have a double-seat valve stuck, it is recommended to switch to sleeve valve, the problem was resolved immediately. 5) Medium scouring method uses the scouring energy of the medium itself to scour away and remove the easily sedimentable and clogged things, so as to improve the anti-clogging function of the valve. Common methods are: ①closed for the flow of closed-type use; ② the use of streamlined body; ③ the throttle placed in the erosion of the most powerful, using this method should pay attention to improve the erosion-resistant materials, parts erosion. 6) Straight through to the angle method Straight through the inverted S flow, the flow path is complex, the upper and lower cavity dead zone, provides a place for the precipitation of the medium. Angular connection, like 90 ° elbow flow through the medium, erosion performance, small dead zone, easy to design streamlined. Therefore, the use of straight through the control valve can be slightly blocked when the valve can be changed to use. Third, the control valve leakage solution (6 methods) 1) increase the seal grease method on the unused seal grease valve, consider increasing the seal grease to improve the valve stem seal performance. 2) Increase the packing method To improve the sealing performance of the packing on the valve rod, increase the packing method. Usually double, multi-layer mixed filler, simply increase the number, such as the 3 to 5, the effect is not obvious. 3) The replacement of graphite packing PTFE used in large quantities due to its operating temperature in the range of -20 ~ +200 ℃, when the temperature in the upper and lower limits, when the change is large, the sealing will be significantly reduced, aging fast, life short. Flexible graphite filler can overcome these shortcomings and long service life. Therefore, some factories will be all PTFE filler to graphite packing, and even replaced the new control valve which will be replaced by graphite packing PTFE packing used. However, the use of graphite packing back to the large, sometimes some crawling phenomenon, which must be considered. 4) to change the flow, set P2 in the stem end method when △ P larger, P1 and larger, the seal P1 is obviously more difficult than the seal P2. Therefore, you can take to change the flow of the method, the P1 end of the rod at the end of the P2 in the valve stem, which is high pressure, large pressure valve is more effective. Such as the bellows valve should normally be considered seal P2.5) The use of lens gasket seal method for the upper and lower lid seal, valve seat and the upper and lower valve body seal. If the plane seal, under high temperature and pressure, poor sealing, causing leakage, you can use a lens pad seal, can be satisfied with the results. 6) Replace the gasket So far, most of the gasket is still asbestos board, at high temperatures, poor sealing performance, short life expectancy, causing leakage. Encountered this situation, you can use the spiral wound gasket, "O" ring, and now many factories have adopted. Fourth, the control valve vibration solution (8 methods) 1) Increase the stiffness method of oscillation and slight vibration, increase the stiffness to eliminate or reduce, such as the use of large stiffness of the spring, the use of piston actuators and other options are feasible of. 2) Increase the damping method to increase the damping that is to increase the vibration of the friction, such as sleeve valve spool can be used "O" ring seal, with a larger friction graphite filler, which to eliminate or reduce the slight vibration or Have a role 3) to increase the size of the guide to reduce the gap with the general orientation of the shaft valve size are small, all valves are generally larger with the gap, there are 0.4 ~ lmm, which produces mechanical vibration is helpful. Therefore, when a slight mechanical vibration occurs, the vibration can be weakened by increasing the guide size and reducing the mating clearance. 4) to change the throttle shape, eliminating the resonance method due to the control valve so-called vibration occurred in the high-speed flow, rapid changes in pressure orifice, changing the shape of the throttle can change the vibration source frequency, the resonance is not strong comparison Easy to solve. The specific method is to be within the scope of the opening of the valve core turning 0.5 ~ 1.0mm. For example, a self-operated pressure regulating valve is installed near the factory area of ​​a factory. The whistle of the resonance causes the worker to rest. After the 0.5mm spool surface is dropped, the resonance whistle disappears. 5) replace the throttle pieces eliminate the resonance method of its methods are: ①replace the flow characteristics, logarithm of linearity, linear change logarithm; ② replace the spool form. Such as the shaft plug into a "V" shaped spool, the two-seat valve shaft type into a sleeve-type; will open the window sleeve to play a small hole sleeve. If a nitrogen fertilizer plant a DN25 two-seater valve, the valve stem and spool connections often broken, we confirmed that the resonance, the linear characteristics of the spool to the logarithmic spool, the problem is solved. Another example is an aeronautical institute laboratory with a DN200 sleeve valve, the valve plug can not be cast with a strong rotation, the opening of the sleeve to a small hole to the sleeve, the rotation disappeared immediately. 6) Change the type of control valve to eliminate resonance Resonant valves with different structures naturally have different natural frequencies. Changing the type of control valve is the most effective way to eliminate the resonance fundamentally. A valve resonates very strongly during use - strongly vibrates (can damage the valve in severe cases), rotates strongly (even the valve stem is shaken and broken) and produces strong noise (up to over 100 dB) Valve, as long as it replaced a valve with a large difference in structure, immediate effect, strong resonance miraculously disappear. Such as a vinylon plant expansion project selected a DN200 sleeve valve, the above three phenomena exist, DN300 pipe followed by the valve plug rotation, the noise 100 dB, the resonance opening 20 ~ 70%, consider the resonance open Degree, use a double seat valve, the resonance disappears, put into operation normally. 7) to reduce the cavitation vibration method due to cavitation bubble rupture and cavitation vibration, should naturally reduce cavitation on the way. ①Let the bubble burst impact energy does not act on the solid surface, especially the spool, but to liquid absorption. Sleeve valve has this feature, so you can change the spool plug sleeve type. ② to reduce cavitation all the ways, such as increasing the throttling resistance, increasing the pressure of systolic orifice, grading or series decompression. 8) to avoid the wave wave hit the external source wave vibration caused by the valve vibration, which is obviously the normal operation of the control valve should be avoided, if the vibration, should take appropriate measures Seven, regulating valve noise Solution (8 methods) 1) Eliminate the resonance noise method Only when the control valve resonance, only the energy superposition produces more than 100 dB strong noise. Some manifestations of strong vibration, noise is not large, some weak vibration, but the noise is very large; some vibration and noise are larger. This kind of noise produces a single tone sound, the frequency is generally 3000 ~ 7000 Hz. Obviously, to eliminate the resonance, the noise will naturally disappear. Methods and examples are given in 4.5 above 4), 5), 6). 2) Elimination of cavitation noise method Cavitation is the main source of hydrodynamic noise. Cavitation, the bubble burst to produce high-speed impact, making it a strong local turbulence, cavitation noise. This type of noise has a wide frequency range and produces a treble sound similar to the sound of gravel contained in a fluid. Eliminating and reducing cavitation is an effective way to eliminate and reduce noise. 3) The use of thick-walled pipe method thick-walled pipe is one way to deal with the sound path. The use of thin walls can increase the noise by 5 dB, the use of thick-walled tubes can reduce noise by 0 to 20 dB. The same diameter wall thicker, the same wall thickness greater diameter, the better the noise reduction. Such as DN200 pipe, the wall thickness was 6.25,6.75,8,10,12.5,15,18,20,21.5mm, the noise can be reduced to -3.5, -2 (ie increase), 0,3,6, 8, 11, 13, 14.5 dB. Of course, the thicker the wall the higher the cost. Eight, control valve vibration solution (8 methods) 1) Increase the stiffness method of oscillation and slight vibration, increase the stiffness to eliminate or reduce, such as the use of large stiffness of the spring, the use of piston actuators and other options are feasible of. 2) Increase the damping method to increase the damping that is to increase the vibration of the friction, such as sleeve valve spool can be used "O" ring seal, with a larger friction graphite filler, which to eliminate or reduce the slight vibration or Have a role 3) to increase the size of the guide to reduce the gap with the general orientation of the shaft valve size are small, all valves are generally larger with the gap, there are 0.4 ~ lmm, which produces mechanical vibration is helpful. Therefore, when a slight mechanical vibration occurs, the vibration can be weakened by increasing the guide size and reducing the mating clearance. 4) to change the throttle shape, eliminating the resonance method due to the control valve so-called vibration occurred in the high-speed flow, rapid changes in pressure orifice, changing the shape of the throttle can change the vibration source frequency, the resonance is not strong comparison Easy to solve. The specific method is to be within the scope of the opening of the valve core turning 0.5 ~ 1.0mm. For example, a self-operated pressure regulating valve is installed near the factory area of ​​a factory. The whistle of the resonance causes the worker to rest. After the 0.5mm spool surface is dropped, the resonance whistle disappears. 5) replace the throttling pieces Eliminate the resonance method with 4.5 in 4), but the replacement of throttling pieces. The methods are: ①replacement of flow characteristics, log linear, linear change logarithm; ② replace the spool form. Such as the shaft plug into a "V" shaped spool, the two-seat valve shaft type into a sleeve-type; will open the window sleeve to play a small hole sleeve. If a nitrogen fertilizer plant a DN25 two-seater valve, the valve stem and spool connections often broken, we confirmed that the resonance, the linear characteristics of the spool to the logarithmic spool, the problem is solved. Another example is an aeronautical institute laboratory with a DN200 sleeve valve, the valve plug can not be cast with a strong rotation, the opening of the sleeve to a small hole to the sleeve, the rotation disappeared immediately. 6) Change the type of control valve to eliminate resonance Resonant valves with different structures naturally have different natural frequencies. Changing the type of control valve is the most effective way to eliminate the resonance fundamentally. A valve resonates very strongly during use - strongly vibrates (can damage the valve in severe cases), rotates strongly (even the valve stem is shaken and broken) and produces strong noise (up to over 100 dB) Valve, as long as it replaced a valve with a large difference in structure, immediate effect, strong resonance miraculously disappear. Such as a vinylon plant expansion project selected a DN200 sleeve valve, the above three phenomena exist, DN300 pipe followed by the valve plug rotation, the noise 100 dB, the resonance opening 20 ~ 70%, consider the resonance open Degree, use a double seat valve, the resonance disappears, put into operation normally. 7) to reduce the cavitation vibration method due to cavitation bubble rupture and cavitation vibration, should naturally reduce cavitation on the way. ①Let the bubble burst impact energy does not act on the solid surface, especially the spool, but to liquid absorption. Sleeve valve has this feature, so you can change the spool plug sleeve type. ② to reduce cavitation all the ways, such as increasing the throttling resistance, increasing the pressure of systolic orifice, grading or series decompression. 8) to avoid the wave wave hit the external source wave vibration caused by the valve vibration, which is obviously the normal operation of the control valve should be avoided, if the vibration, it should take appropriate measures nine, regulating valve noise Solution (8 methods) 1) Eliminate the resonance noise method Only when the control valve resonance, only the energy superposition produces more than 100 dB strong noise. Some manifestations of strong vibration, noise is not large, some weak vibration, but the noise is very large; some vibration and noise are larger. This kind of noise produces a single tone sound, the frequency is generally 3000 ~ 7000 Hz. Obviously, to eliminate the resonance, the noise will naturally disappear. Methods and examples are given in 4.5 above 4), 5), 6). 2) Elimination of cavitation noise method Cavitation is the main source of hydrodynamic noise. Cavitation, the bubble burst to produce high-speed impact, making it a strong local turbulence, cavitation noise. This type of noise has a wide frequency range and produces a treble sound similar to the sound of gravel contained in a fluid. Eliminating and reducing cavitation is an effective way to eliminate and reduce noise. 3) The use of thick-walled pipe method thick-walled pipe is one way to deal with the sound path. The use of thin walls can increase the noise by 5 dB, the use of thick-walled tubes can reduce noise by 0 to 20 dB. The same diameter wall thicker, the same wall thickness greater diameter, the better the noise reduction. Such as DN200 pipe, the wall thickness was 6.25,6.75,8,10,12.5,15,18,20,21.5mm, the noise can be reduced to -3.5, -2 (ie increase), 0,3,6, 8, 11, 13, 14.5 dB. Of course, the thicker the wall the higher the cost. 4) The use of sound-absorbing material method This is also a more common and most effective sound path approach. Sound-absorbing material can be used to surround the noise source and the valve after the pipeline. It must be pointed out that because of the long-distance propagation of noise through the fluid flow, where the sound-absorbing material is wrapped and where thick-walled tubes are used, the effectiveness of noise cancellation ends. This approach applies to the noise is not very high, the pipeline is not very long, because this is a more expensive way. 5) Tandem muffler method This method is suitable for silencing as aerodynamic noise, it can effectively eliminate the noise inside the fluid and inhibit the noise level transmitted to the solid boundary layer. This method is most effective and economical for places with high mass flow rate or high pressure drop before and after the valve. The use of absorption series silencer can significantly reduce the noise. However, economically, it is generally limited to decay to about 25 dB. 6) Sound Box Method Sound box, house and building are used to isolate the noise source and reduce the external environment noise to the acceptable range. 7) Series throttling method When the pressure ratio of the regulating valve is high (ΔP / P1≥0.8), the series throttling method is to distribute the total pressure drop to the fixed throttling element after the regulating valve and the valve. Such as the use of diffusers, porous restrictor, which is the most effective way to reduce noise. In order to get the best diffuser efficiency, the diffuser (physical shape, size) must be designed for each piece of installation so that the valve produces the same noise level as the diffuser. 8) Selection of low noise valve Low noise valve According to the fluid through the valve core, the seat of the tortuous flow path (multi-channel, multi-channel) of the gradual deceleration, to avoid any point in the flow path to produce supersonic. A variety of forms, a variety of structures of low-noise valves (designed for specialized systems) for use when used. When the noise is not large, the choice of low noise sleeve valve, can reduce the noise 10 to 20 dB, which is the most economical low noise valve. Ten, the control valve when the poor stability of the solution (5 methods) 1) change the direction of unbalanced force method in the stability analysis, known unbalanced force with the same direction and valve closing, that is, the valve When the trend is closed, the valve stability is poor. Work on the valve in the unbalanced conditions, the choice of changing the direction of its method, the flow is usually closed to open type, generally can easily solve the problem of valve stability. 2) to avoid valve instability zone valve some of its working structure of its own restrictions on the work in certain degree of stability when the poor stability. ①double-seat valve, the opening of less than 10%, due to the ball on the open at the ball Department at the closure, bringing instability; ② unbalanced force change slope near the alternating, its stability is poor. Such as butterfly valve, alternating point at about 70 degrees; double seat valve in the 80 ~ 90% opening. In case of such valve, the inevitable stability in the work of unstable areas, to avoid the work of unstable areas. 3) replace the valve with good stability and good stability of the valve change in its unbalance small, good guidance. Ball valve commonly used, the sleeve valve has this great feature. When a single, double seat valve stability is poor, the replacement of sleeve valve stability will be improved. 4) increase the spring stiffness Act enforcement agencies to resist load changes on the impact of the ability to rely on the spring stiffness, the greater the stiffness, the smaller the impact on the trip, the better valve stability. Increase the spring stiffness is to improve the stability of the valve common simple method, such as the spring range of 20 ~ 100KPa into a 60 ~ 180KPa spring of large stiffness, this method is mainly used with a retainer valve, otherwise, the use of Valve to be additionally equipped with locator. 5) to reduce the response speed method When the system requirements regulator valve response or adjustment speed should not be too fast, the valve response and adjustment speed but fast, such as the flow needs to be fine-tuned, and the control valve flow regulation varies greatly, or The system itself is a quick response system and a regulating valve but with a positioner to speed up the valve action, which are both detrimental. This will produce overshoot, vibration and so on. In this regard, should reduce the response speed. There are ways: ①the linear characteristics of the logarithmic characteristics; ② with the locator can be changed to the converter, the relay. 4) Symmetric tightening of bolts, using a thin gasket sealing method In the "O" ring seal control valve structure, the use of a larger deformation of the gasket (such as winding sheet), if the compression asymmetry, asymmetric stress , Easy to seal damage, tilt and deformation, seriously affecting the sealing performance. Therefore, in this type of valve repair, assembly, the bolts must be symmetrically tightened (note can not be tightened at a time). Thick gaskets can be better turned into thin gaskets, which makes it easy to reduce the slope and ensure a tight seal. 5) Increase the sealing surface width, to prevent the flat spool off and reduce the amount of leakage when the method of flat-shaped spool (such as two-valve, sleeve valve spool), no guidance in the valve seat and the guide surface , Due to the valve at work, the spool by the lateral force from the inflow side to the flow side, the larger the spool with the gap, the more serious this unilateral, coupled with deformation, different heart, or spool sealing surface down Angle is small (usually 30 ° chamfer to guide), so close to close, the spool sealing surface is placed on the valve seat sealing surface, resulting in the closure of the valve core beating, or even not close at all, so that the valve Leakage greatly increased. The simplest and most effective solution is to increase the size of the sealing surface of the valve plug so that the minimum diameter of the valve plug end is 1 to 5 mm smaller than the valve seat diameter so as to guide the valve plug to the valve seat Good sealing surface contact. 6) to change the flow to solve the problem of promoting the Commissioner to eliminate Surge Law two-type valve to improve the shut-off effect, usually used as a closed flow. The liquid medium, due to the role of flow closed unbalanced force is the spool closed, there is the role of promoting the Commissioner, also known as pumping action to speed up the valve spool speed, resulting in a slight water hammer, causing the system surge. The solution to the above phenomenon is that as soon as the flow direction is changed to flow, surge can be eliminated. A similar problem that may affect the valve's inability to work properly may also be considered in this way. 7) The most typical valve to overcome the fluid destructive method is the double-seat valve, the fluid enters from the middle, the spool is perpendicular to the inlet, and the fluid is divided into upper and lower two streams to flow around the spool. The fluid impinges on the spool, causing it to lean toward the outlet side, causing friction and damaging the spool and bush guide surfaces, resulting in maladjustment. High flow rates may also cause the spool to flex, erode, or even rupture in severe cases. The solution: ①improve the hardness of the guide parts of the material; ② increase the spool up and down the middle of the ball size, so that was rough; ③ alternative use of alternative valves. As with the sleeve valve, the flow of fluid around the sleeve, the lateral thrust of the valve plug greatly reduced. 8) to overcome the fluid rotation force to make the valve core rotation method of the "V" -shaped port of the valve spool, due to the media inflow asymmetry, acting on the "V" port on the spool tangential force inconsistencies, resulting in a so that Rotating rotation force. Especially for DN ≥ 100 valve is more intense. As a result, it is possible to cause disengagement of the valve and actuator ram connection, which may cause the diaphragm to distort. The solution is: ①anti-rotation of the spool at an angle to balance the role of the tangential force on the spool; ② further lock the stem and the push rod connection, if necessary, add a piece of anti-rotation of the splint; ③ the "V" -shaped opening of the spool to replace the spool-shaped spool; ④ adopt or change to a sleeve-type structure; ⑤ If the resonance caused by rotation, the elimination of resonance can solve the problem. 9) Adjust the disc valve disc friction to overcome the open beating method using "O" ring, seal ring, liner and other soft-sealed butterfly valve, the valve is closed, due to the deformation of the soft seal, the valve plate in place and wrap valve Board, can achieve very good cut off effect. However, when the valve is to be opened, the actuator's force to open the valve plate increases. When the frictional force of the soft seal to the valve plate increases, the valve plate starts. Once activated, this friction decreases drastically. To achieve the balance of power, the valve plate open violently, this force with the corresponding opening degree of the role of the media unbalanced moment and the opening torque of the actuator balance, the valve stops at this opening. This violent and sudden take-off opening can be as high as 30 to 50%, which will have a series of problems. At the same time, due to the closure of the soft seal to produce greater changes, easy to produce permanent deformation or squeeze the valve plate damage, such as strain, affect life expectancy. The solution is to adjust the soft seal on the valve plate to start the friction, which can not only ensure the required cut off requirements, but also make the valve more normal start. The specific measures are: ①adjust the amount of interference; ② limit or adjust the actuator preload, the output force approach to reduce the valve plate to open over the open to bring the difficulties.