Maintenance of Pneumatic Flanged Ball Valves

Routine and periodic maintenance includes flushing the pipeline and the valve's flow path before use to remove residual debris; ensure the pipeline and valve have been flushed prior to operation. Regularly check that the air supply pressure is adequate, inspect the positioner for abnormalities, and verify the condition of actuator accessories.
Before cleaning or servicing, close the upstream isolation valve and fully depressurize the valve body; for electric or pneumatic ball valves, disconnect the power and air supplies first. Soft-seated ball valves utilize PTFE for sealing, while hard-seated valves feature metal-overlay sealing surfaces; exercise caution during cleaning to avoid damaging the seal rings. Secure flange bolts and nuts by tightening them lightly at first, then fully tightening them with the required torque. Cleaning solvents must be compatible with the components and non-corrosive; gasoline may be used for gas-service ball valves, while other parts are typically cleaned with water or alcohol.
When troubleshooting malfunctions-such as the valve failing to open or close fully-check the air supply pressure and the positioner, and inspect sealing surfaces for trapped debris; adjust pressure, repair or replace the positioner, or disassemble the valve to clear debris and replace the seat as necessary. Common leakage points include the air service unit (FRL), cylinder exhaust ports, solenoid valves, and the upper and lower sections of the cylinder shaft.
For long-term outdoor storage, protect the valve from rain and moisture, and ensure flange covers are securely fastened; valves stored for more than 12 months should undergo re-testing before use to ensure stable performance.