SCH8O/DIN Pneumatic Flange Ball Valve

Common fault diagnosis and maintenance practices of pneumatic flange ball valves (multi-industry application scenarios)

Pneumatic flange ball valves are widely used in safe drinking water, metallurgy, photovoltaics, nuclear power, electronic semiconductors, medicine, industrial water treatment, industrial wastewater and other fields due to their fast opening and closing, good sealing, and high pressure resistance. However, in long-term operation, failures may occur due to medium characteristics, working conditions or improper operation. The following are common problems and maintenance suggestions, which are analyzed in combination with different industry scenarios:

1. Common fault diagnosis and solutions
Valve internal or external leakage
Possible causes: wear of the sealing ring (such as long-term high temperature aging of PTFE), damage to the valve seat, and loose flange bolts.

Industry application differences:
Medicine/electronic semiconductor: High-purity media require zero leakage, and the valve seat material needs to be checked regularly (such as PPL reinforced polytetrafluoroethylene).
Nuclear power/industrial wastewater: Corrosive media (such as acid and alkali) are easy to corrode the valve body, and Hastelloy or fluorine-lined valves should be used.

Pneumatic actuators are slow or fail
Possible reasons: insufficient air source pressure, solenoid valve failure, water accumulation in the cylinder (compressed air is not dry).

Industry application differences:
Photovoltaic/metallurgy: High temperature environment causes more condensed water in the air source pipeline, and an air dryer needs to be installed.
Safe drinking water: Humid environment may cause actuator corrosion, and IP67 protection level is recommended.

Valve stuck or unable to switch
Possible reasons: medium crystallization (such as salt in industrial wastewater), impurity accumulation (such as silt in water treatment), long-term lack of maintenance.

Industry application differences:
Industrial water treatment: Rinse the valve cavity regularly to prevent particulate matter from blocking.
Electronic semiconductors: Metal ion contamination should be avoided in ultrapure water systems, and fully lined valves are recommended.

2. Targeted maintenance practices
Regular inspection and cleaning
Safe drinking water/pharmaceutical industry: Disassemble and inspect seals every quarter to ensure that there is no biofilm or chemical residue.
Photovoltaic/semiconductor: Use high-purity nitrogen to purge the gas line to prevent particle contamination.

Lubrication and sealing management
Metallurgy/nuclear power: Use high-temperature resistant grease (such as silicone-based grease) under high-temperature conditions to avoid dry friction.
Industrial wastewater: In corrosive media environments, it is recommended to use bellows + graphite packing for double protection of valve stem seals.

Pneumatic system maintenance
Common to all industries:
Check the gas source triplex (filter, pressure reducing valve, oil mist collector) to ensure stable pressure (usually 0.4~0.6MPa).
Solenoid valves and limit switches must be dust-proof and moisture-proof, especially for outdoor environments of photovoltaic plants.

3. Special precautions for the industry
Nuclear power: Must comply with ASME III or RCC-M standards, and the valve body material must be radiation-resistant (such as 316L ultra-low carbon stainless steel).
Electronic semiconductors: Electrolytic polishing (Ra≤0.4μm) of the surface of the valve in contact with the medium to prevent particles from falling off.
Medicine: Under sterilization (SIP/CIP) conditions, the valve must withstand high-temperature steam cycles above 120°C.