Service life and troubleshooting of soft sealed gate valves
Soft sealed gate valves have been widely used in the water supply industry due to their characteristics such as zero leakage, low slag accumulation and no grooves, functional anti-corrosion properties such as epoxy coating, good interchangeability, and long service life. The connection between the gate plate and the valve stem nut of a soft sealed gate valve can be divided into two types: T-nut type and fully embedded. The T-nut type structure is complex, and there is an adjustment gap between the nut and the gate plate, which can simplify the gate plate manufacturing process and reduce requirements. However, temporary use may cause the T-nut to wear out the rubber layer of the gate plate, expose the iron core, and cause rust. AWWAC509 and AWWAC515 recommend this structure. The entire embedded structure is complex, with no adjustment gap between the nut and the gate. The manufacturing process of the gate is complex, and high precision is required for the processing and assembly of each component. However, the structure is reliable and there will be no rubber layer wear. The CJ/T216 standard recommends using this structure.
Soft seal gate valves are divided into two types: open stem soft seal gate valves and concealed stem soft seal gate valves. Usually, there is a trapezoidal thread on the lifting rod, which passes through the nut in the middle of the gate and the guide groove on the valve body, transforming the rotational motion into linear motion, that is, transforming the operating torque into the operating thrust. The soft sealed gate valve is powered by compressed air, and the ball rod drives the ball to rotate 90 degrees to complete the fully open to fully closed action. Valve seat type: T, F, C type. The accessories used in conjunction with it include air filter pressure reducing valve, limit switch, and solenoid valve. The main function of the air filtration pressure reducing valve is to firmly pressure and filter out impurities and water vapor in the air.
Corresponding disposal methods for soft sealed gate valves:
1. Replace the sealing ring of the actuator.
2. Replace the sealing ring at the cylinder.
3. Adjust the pressure of the pressure reducing valve to 3-5 kilograms, perhaps by removing the old gas from the lower part of the solenoid valve several times, or sometimes replacing the solenoid valve.
4. Replace the spring in the cylinder.
