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Control valve failure
Often with the control valve repair work has a great relationship. Control valve failure varied, and the emergence of a failure may also have different reasons. First, the main fault components of the implementing agencies Different types of control valves and different parts have some key components, these components are also prone to failure components. 1, pneumatic, hydraulic actuator a diaphragm on the film pneumatic actuator, the diaphragm is the most important component in the normal gas supply system, if the actuator does not move, you should think of whether the diaphragm Cracked, is not installed. When the surface of the metal contact surface has sharp corners, burrs and other defects when the diaphragm will be punctured, and the diaphragm must not have a leak. In addition, the diaphragm is used for too long, material aging will also affect the use. b, Piston Pneumatic, hydraulic actuator piston to produce driving force, so the piston damage, wear is absolutely not allowed. c, gas (liquid) pipe This is the input pressure to the implementing agencies access, it should always check whether the prison, airtight. d, putter to check whether the pushrod bending, deformation, fall off. Pusher and valve stem to be firmly connected to the position to be adjusted so as to ensure adequate stroke and close the valve. e, spring to check whether the spring break. Manufacturing, processing, improper heat treatment will make the spring break. Some springs may break under excessive load. 2, the electric actuator a, motor check whether the motor can rotate, whether it is easy to overheat, whether there is enough torque and coupling force. b, servo amplifier check whether there is output, whether to adjust. c, deceleration mechanism The manufacturers of the deceleration mechanism vary. Therefore, to check the transmission parts - shafts, gears, worm gear, etc. are damaged, is worn too large. d, torque controller according to the specific structure to check the cause of failure. Second, the main valve failure components a, the valve body to always check the corrosion of the inner wall and wear and tear, especially for corrosive media and high pressure differential, cavitation and other adverse conditions under the valve, you must ensure that the pressure Strength and corrosion resistance, wear resistance. b, the spool as a valve to play the role of regulation and cut off the fluid is the activities of the intercepting components, so by the media erosion, corrosion, particle collision is the most important in the high pressure differential, cavitation more likely to damage, so Check all parts of it is damaged, worn, corroded, whether to repair or replacement. c, valve seat joint surface is to ensure the closure of the key valve, it is rotten by the rotten situation is more serious. And because of the media infiltration, so that the fixed valve seat thread surface often corroded and loose, to be a special inspection of this site. d, the stem to check the stem and the spool, push rod connection with or without loosening, whether excessive deformation, cracks and corrosion. e, packing Check polytetrafluoroethylene or other filler is aging, lack of oil, deterioration, packing is compressed. f, gaskets and o-ring these fragile parts can not be cracked, aging