Pneumatic diaphragm regulating pneumatic valve failure and solving methods

pneumatic diaphragm regulating pneumatic valve in the running, there will be various kinds of process medium flows through the automatic pneumatic valve, including process raw block material, steam flushing to sand, stone, iron, tin, and the instrument installation and technical improvement of welding, flame cutting off into the pipe welding slag, etc. These foreign bodies and choke material, impact on the normal work and accuracy of automatic pneumatic valve is larger, as time passes, will form the jams, jammed.
field generally take the following measures:
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( Cleaning method. This method is suitable for use in the process when parking overhaul. Need to remove the regulating pneumatic valve cleaning, remove dirt and foreign material. It is worth noting that the disassembly, be sure to turn off the compressed air, lest cause unnecessary damage. Instrument of gasket and seal also had better change at the same time.
( Using the method of scour. This method used more at the scene. When regulating pneumatic valve jam, usually is first inquiry process or OCC, director of the personnel, whether can be repeatedly switch automatic pneumatic valve, the flow of the use of existing technology medium pressure to achieve the purpose of washing. Such as working condition of the existing medium and doesn't fit, can also in the case of a condition is met, with foreign steam or have certain pressure water to wash. Rinse, pay attention to the pneumatic valve opening control in the appropriate position.
( The installed filter. In the process piping installed filters is also a common measure of instrument automatic pneumatic valve maintenance. Especially on craft is very important and the adjustment of smaller diameter pneumatic valve use this method, can ensure the automatic pneumatic valve opening is normal, stable condition.
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regulating pneumatic valve pneumatic seat leakage into smaller, iron slag and hard objects within a long stay cannot eduction, the pneumatic valve cushion, seal and pneumatic valve core will get different degrees of damage effect to adjust the leakage of pneumatic valve. Especially to the reaction kettle of hydrogen production technology of high pressure pipeline automatic pneumatic valve, a little bit of damage even scratches will cause leakage, affect the safety in production.
( Grinding. Choose corresponding coarse sand and fine sand for automatic pneumatic valve pneumatic valve grinding pad and pneumatic valve core, improve the pneumatic valve pad and the smoothness of the sealing contact surface of the pneumatic valve core and mesh. If regulating pneumatic valve used in high pressure system, the need to adjust the pneumatic valve crackdown after test, normal use.
( Enhance actuator seal. By this method can guarantee to adjust the closing of the pneumatic valve, sealing is reliable. Usually adopt mobile spring's scope of work, choose big power source selection of actuators and small stiffness of the spring.
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regulating pneumatic valve leakage of the packing is not timely replacement, automatic pneumatic valve locking device of screw loosening due to vibration, including screw not just the regulating pneumatic valve after the maintenance base school tight or uneven force leads to adjust the leakage of pneumatic valve. Can adopt the following measures:
( Replacement of new packing to enhance pneumatic valve stem seal, also can select sealing grease on pneumatic valve stem seal.
( Can use high sealing metal winding gasket appropriately or ptfe packing, especially steam regulating pneumatic valve, must choose metal winding gasket with graphite.
( The lens gasket to seal the upper and lower cover, if is pneumatic and pneumatic valve seating plane sealing, suggest choose lens gasket seal, effect is remarkable.
and regulating pneumatic valve control instability
some of the reasons for control of instability, such as the selection of design is unreasonable, pneumatic valve diameter chosen too small or too large; OCC process operators use undeserved, instrument and process parameter Settings are unreasonable; No debug configuration error; Process of medium pressure, flow instability, etc. ; Sometimes these factors lead to the result of joint action.
often take the following methods:
( Choose the right pneumatic valve diameter. If considering the economy and time, also can consider to choose the appropriate variable diameter to decrease or increase the adjustment of the pneumatic valve and piping connection pipe diameter.
( To reasonable set of PID value, and through practical test and operation of qualified after put into use.
( Strengthen adjust the stiffness of pneumatic valve movement organizations, to alleviate the vibration of the pneumatic valve adjustment.
( Adjustment to adjust the results of the pneumatic valve type, avoid the happening of resonance phenomena.