The methods of dealing with the electric control valve closed lax
Electric control valve is the special valve regulating medium flow, valves according to the measured parameters ( Such as temperature, pressure, flow rate, etc. ) , at a constant parameter being measured, for the purpose of automatic control valve opening. Because of electric regulator precision regulating function, make the valve leakage soft rib of such products. Here introduce a few kinds of regulator of leakage treatment. 1, the executing agency zero set is not accurate, not reached the seated position of the valve. Adjust way: 1) Closing the valve manually ( Must be confirmed completely shut down) ; 2) Reoccupy force close the valve manually, but use a strength twist fixed shall prevail; 3) Turn back again, Open valve direction) Half a circle; 4) And then adjust the limit. 2, the valves are pushed down closed type, thrust of the actuator is not big enough, in the absence of pressure debugging is easy to achieve, fitted with thrust, cannot overcome liquid upward thrust, so does not reach the designated position. Solution: replace the big thrust actuator, or type instead of the balance valve core to reduce the unbalanced force of medium. 3, electric control valve manufacturing quality caused by the leakage, the valve manufacturer in the process of production of material, processing technology and assembly process control valve is lax, the sealing surface grinding is unqualified, the pitting, products are not completely eliminate defects such as trachoma, caused the electric regulating valve leakage. Solution: reprocessed seal face. 4, electric regulating valve control part affect the internal leakage of the valve, electric control valve of the traditional control method is through the valve and mechanical limit switch, a torque switch control mode, because the control element is affected by environmental temperature, pressure, humidity, causing the valve positioning, spring fatigue, thermal expansion coefficient of inhomogeneous objective factors, such as electric control valve leakage. Solution: adjust the limit again. 5, electric regulator debugging problems caused by leakage, affected by the processing, the assembly process, electric regulator are widespread manually locked after electric wouldn't open. Such as motion through the upper and lower limit switch position of the electric control valve stroke adjustment, electric regulating valve in closed lax or valve open exhibition is not ideal; The electric control valve stroke adjustment a few bigger, the cause of torque switch protection action; If the adjustment of torque switch action value, reduction drive crashed in institutions or damaged valve, even to the motor burned accident. In order to solve this problem, usually, the electric control valve when debugging manual electric regulator shake, shake a circle towards the direction to open again, set the lower limit of the electric door switch position, and then puts the electric control valve to full open position limit switch position, won't appear such electric regulator manually locked after electric wouldn't open phenomenon, to make the electric door open and close operation freely, but virtually caused the electric gate leakage. Even electric regulator adjusting ideal, because of the limit switch action position is relatively fixed, in the operation of the valve control the media in the valve of scour, wear, also can cause leakage phenomenon caused by valve closing is lax. Solution: adjust the limit again. 6, selection error caused by valve cavitation electric control valve leakage caused by corrosion, cavitation is related to pressure difference, when the actual pressure differential valve delta P is greater than produce cavitation critical pressure differential delta Pc, will produce cavitation, in the process of cavitation bubbles burst release enormous energy, the valve seat, valve core has great damage, the throttling components such as general valve under the condition of cavitation run no more than three months, or even shorter time, the valves are subjected to severe cavitation corrosion, the high seat leakage can reach more than 30% of the rated flow, this is irreparable, therefore, different USES have different specific technical requirements of electric valve, according to system process to choose reasonable electric regulating valve is very important. Solution: process improvement, choose multi-stage decompression or sleeve regulator. 7, medium scour, electric control valve leakage caused by aging, electric regulator to adjust after a certain time after the operation, due to the cavitation of the valve and the medium of scour, valve core and valve seat wear, internal components aging causes, electric regulator slants big, will appear the phenomenon of electric control valve closed lax, electric control valve leakage caused by quantitative change is big, with the passage of time, the electric control valve leakage phenomenon will be more and more serious. Solution: adjust the actuators, and regular maintenance, calibration.