How do you repair regulator malfunction?
Regulator directly control medium, and automatic control of the terminal element, so in addition to the valve itself fault happened, all control instrument fault or wrong operation, focuses on the control valve, so how did you know regulator malfunction repair? To introduce the below: when the fault occurs, the performance of the regulating valve repair cannot satisfy the control requirement. Regulator once safety performance out of the problem, or can't normal operation, unable to meet the requirements of automatic control system, then broke down, must be repaired. Chemical plant, power plant of periodic overhaul are classified as this type of repair. : clean pipeline after unloading, cool, remove the valve must be clean. General medium water or water vapor purging, soak. Of acid, alkali, radioactive, or other poisonous and harmful corrosive medium with special craft processing, avoid affecting human health, prevent environmental pollution. Remove valve: the actuator and the valve first open it, open it before hang tags, the joint mark. Then put on the cover removed from the valve body, also want to do in the joint of flange in the tag. Remove the valve core - in the valve body Stem parts, the sleeve and the valve body gasket, double end studs; Unscrew seat, seat cushion ( If there is one) 。 Removed from the valve cover packing flange, gland, hook out of the packing, gasket, etc. ; To be removed after the first wash, focusing on the following several parts: body, the lining damage; Valve core and valve seat, and the throttling face damage degree, decide whether to repair; The valve stem, and loose threads for the connection of valve core, the valve stem is bending, deformation, wear and tear; Packing, whether deformation, aging, generally will not be repeated use; The valve body gasket, seat cushion, generally do not repeat use. Remove the actuator: pneumatic membrane around the head of the bolt down, remove the diaphragm, the spring - Push rod parts, remove the scaffolding of the o-ring, etc. Clean, carefully check. ( Diaphragm, check for ageing, crack, net cloth degumming; Spring, check whether there is any crack on the surface corrosion degree,, with or without permanent deformation; Whether o-ring, aging, wear and fracture; Push rod with and without deformation, rust; Such as piston actuator, check whether there is any wear and tear on the inner wall of the cylinder, hair, piston ring and guide whether aging and wear and tear, piston and piston rod deformation, wear and tear) Reassemble the: after the inspection, parts after repair, exchange can reassemble. Then connect two components into the machine. When assembling, add grease should be paid attention to. With the valve positioner, air filtration pressure reducer etc. The auxiliary instrument repair, testing qualified after the installation in place. Performance testing: assembly of the regulator in accordance with the project test inspection, such as air tightness, sealing, crushing strength, leakage, and basic error, return difference, dead zone, rated travel, always point deviation. On the occasion of special needs and do rated flow, flow characteristics test. Commonly used spare parts, maintenance of the accident before, usually to prepare the following parts: the body parts, packing, valve body gasket, seat cushion, double-headed stud, safety pin, etc. ; Pneumatic actuators parts, O shaped rubber ring, piston ring, membrane cover bolts; Pay a certain percentage of actuators with the specifications and quantity, diaphragm, spring. Other parts, such as valve core, valve seat, valve stem, sleeve, packing flange, etc. , because its price is more expensive, usually not good in advance and stay open after checking decided to need to exchange, to buy from the original factory.