Electric control pneumatic valve leakage reason and solution

Electric control pneumatic valve with its advantages of high control precision, easy installation and debugging in a variety of industrial control system has been more and more widely used, its stability is more and more important, its working condition is good or bad will directly affect the automatic control process. However, in use process, there are also some problems with the field instruments, pneumatic valve leakage problem is. Here we will discuss within the common electric regulating pneumatic valve leakage causes and solutions, hoping to on-site maintenance personnel to the factory have a little help.

1, the executing agency zero set is not accurate, not reached the seated position of pneumatic valve.

adjustment methods: 1) Closing the pneumatic valve manually ( Must be confirmed completely shut down) ； 2) Reoccupy force close the pneumatic valve manually, but use a strength twist fixed shall prevail; 3) Turn back again, Pneumatic valve direction) Half a circle; 4) And then adjust the limit.

2, pneumatic valves are pushed down closed type, the 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.

the solution: replace the big thrust actuator, or the balanced pneumatic valve core to reduce the unbalanced force of medium.

3, electric control in pneumatic valve manufacturing quality caused by the leak valve manufacturers in the process of production of pneumatic valve materials, processing technology and assembly process control is lax, the sealing surface grinding is unqualified, the pitting, products are not completely eliminate defects such as trachoma, caused the electric regulating pneumatic valve leakage.

the solution: reprocessed seal face.

4, electric pneumatic valve control part pneumatic valve leakage electric adjusting the traditional control mode of the pneumatic valve is through the pneumatic valve machinery, limit switch, a torque switch control mode, because the control element is affected by environmental temperature, pressure, humidity, causing pneumatic valve positioning, spring fatigue, thermal expansion coefficient of inhomogeneous objective factors, such as electric regulating pneumatic valve leakage.

the solution: to adjust the limit.

5, electric pneumatic valve debugging problems caused by the leakage because of the influence of processing and assembly process, is common electric regulating pneumatic valve manually locked after electric wouldn't open phenomenon, such as through the action of upper and lower limit switch position adjust electric pneumatic valve stroke adjustment, appear electric regulating pneumatic valve clearance is lax or pneumatic valve open exhibition is not ideal; Adjust electric pneumatic valve stroke adjustment is bigger, the cause of torque switch protection action; If the adjustment of torque switch action value, reduction drive crashed in institutions or pneumatic valve, crashed to motor burned even accidents. In order to solve this problem, usually, the electric control pneumatic valve commissioning, manual electric regulating pneumatic valve swing open direction again shake a circle, set the lower limit of the electric door switch position, then regulate electric pneumatic valve to open to the full open position limit switch position, won't appear such electric pneumatic valve 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 adjust the ideal of pneumatic valve adjustment, because of the limit switch action position is relatively fixed, pneumatic control valve of the medium in the operation of pneumatic valve constantly scour, wear, also causes the pneumatic valve closed lax and cause of leakage phenomenon.

the solution: to adjust the limit.

6, selection error caused by the cavitation corrosion of the pneumatic valve electric to adjust the internal leakage of pneumatic valve cavitation related to pressure difference, when the actual differential pressure delta P is greater than the pneumatic valve produce cavitation critical pressure differential delta Pc, produce cavitation and cavitation bubble burst in the process of releasing vast amounts of energy, such as pneumatic valve seat, pneumatic valve core throttling element generated enormous damage, the general pneumatic valve under the condition of cavitation run no more than three months, or even shorter time, the pneumatic valves are subjected to severe cavitation corrosion, the pneumatic valve seat leakage up to more than 30% of the rated flow, this is irreparable, therefore, different USES electric door has different specific technical requirements, according to system process to choose reasonable electric regulating pneumatic valve is very important.

the solution: process improvement, selection of multi-stage decompression or regulate pneumatic valve socket.

7, medium scour, electric regulating pneumatic valve leakage caused by aging electric pneumatic valve adjust after a certain time after operation, the pneumatic valve cavitation and medium scour, pneumatic valve core and valve seat wear, internal components aging causes, regulated electric pneumatic valve stroke will appear larger, electric regulating pneumatic valve closed lax phenomenon, caused by electric adjustment pneumatic valve leakage quantity is big, with the passage of time, the electric control pneumatic valve leakage phenomenon will be more and more serious.

the solution: to adjust the actuators, and regular maintenance and calibration.