How to Check the Condition of a Gas Pressure Reducer/Regulator?

I. Visual and Installation Inspection

1. Identification and Completeness of Components

• Check if the valve body has clear brand markings, model parameters (such as inlet/outlet pressure ranges), and whether it is within the valid period (some regulators have service life limits).
• Verify that components are complete (e.g., pressure gauges, safety shut-off valves, bypass valves, etc.), and ensure connection interfaces are not loose, deformed, or corroded.

2. Installation Direction and Sealing

• Confirm that the regulator’s installation direction aligns with the gas flow direction (indicated by an arrow on the valve body) to avoid failure due to reverse installation.
• Apply soapy water to interface points (e.g., inlet/outlet flanges, threaded connections) and observe for bubbles. If bubbles appear, it indicates a leak, requiring immediate repair or replacement.
   

II. Pressure Testing (Requires Professional Tools)

1. Static Pressure Test (Closed State)

• Procedure:
  1. Close the inlet and outlet valves of the regulator and disconnect the downstream pipeline (or ensure no gas appliances are in operation downstream).
  2. Connect a precision pressure gauge to the regulator’s inlet and slowly introduce nitrogen or compressed air (pressure should not exceed the regulator’s maximum allowable inlet pressure).
  3. After stabilizing the pressure, observe whether the pressure gauge reading drops by more than 1% within 30 minutes (standards may vary; refer to the product manual).
• Judgment Criteria: Significant pressure drop may indicate aging of valve body seals, valve core wear, or diaphragm damage, requiring disassembly for inspection or replacement.

2. Dynamic Pressure Test (Operating State)

• Procedure:
  1. Keep the regulator normally connected, open the inlet and outlet valves, and allow gas to flow normally.
  2. Install pressure gauges at both the inlet and outlet of the regulator to check if the operating pressure matches the design values (e.g., the outlet pressure of household reducers is typically around 2.8 kPa; industrial regulators should be adjusted according to design parameters).
  3. Simulate load changes: Slowly open or close downstream gas appliances (e.g., gas stoves, water heaters) and observe whether the outlet pressure fluctuation remains within the allowable range (generally no more than ±10%).
• Judgment Criteria:
  • If the outlet pressure consistently exceeds or falls below the set value, the spring may be 失效 (failed), the diaphragm deformed, or the valve core stuck.
  • Severe pressure fluctuations during load changes indicate insufficient regulatory sensitivity, requiring adjustment of spring preload or replacement of components.
     

III. Functional and Safety Performance Verification

1. Safety Shut-Off Valve Test

• Some regulators are equipped with safety shut-off valves (automatically close during overpressure or underpressure), which can be tested as follows:
  • Overpressure Shut-Off: Gradually increase the inlet pressure until the shut-off valve triggers closure, and record whether the shut-off pressure falls within the set range (e.g., the set shut-off pressure is 1.5 times the outlet pressure).
  • Underpressure Shut-Off: Reduce the inlet pressure or artificially create a downstream leak, then observe if the shut-off valve automatically closes during underpressure.
• If the shut-off valve fails to trigger or the trigger pressure deviates from the set value, recalibrate or replace the shut-off device.

2. Relief Valve Test (if applicable)

• For regulators with relief valves, gradually increase the outlet pressure to the relief valve’s opening pressure and observe if it vents pressure normally and whether the valve can automatically close after pressure stabilization.
• If the relief valve does not activate or leaks after closure, inspect the valve core seal or spring performance.

3. Noise and Vibration Inspection

• The regulator should operate without abnormal noise (e.g., whistling, vibrating sounds) under normal conditions. Sharp noises or severe vibrations may indicate gas flow erosion of the valve core, valve body resonance, or loose internal components, requiring disassembly for inspection.

IV. Common Faults and Solutions

V. Precautions

1. Safety First: (Strictly prohibit) open flames during testing, ensure good ventilation, and wear protective equipment in industrial environments.
2. Professional Operation: For pressure testing and disassembly repairs, household regulators should be handled by professional personnel from gas companies, while industrial regulators must be operated by certified personnel following standard procedures.
3. Regular Maintenance: Household regulators are recommended to be inspected annually, while industrial regulators require increased inspection frequency based on usage (e.g., quarterly) and detailed maintenance records.