Valve Performance Inspection

1. Appearance and Marking Inspection
Inspection Content: Check whether the appearance of the valve has defects, such as cracks, bubbles, dents, etc.; check whether the markings, nameplates and surface treatments meet the requirements.
Standards: International standards include API 598, ASME B16.34, ISO 5208, etc.; Chinese standards include GB/T 12224 (General Requirements for Steel Valves), GB/T 12237 (Steel Ball Valves for Petroleum, Petrochemical and Related Industries), etc.
Detection Method: Determine whether there are obvious defects on the valve surface through visual inspection and hand inspection, and check whether the marking and nameplate information are correct.

2. Dimension Measurement
Inspection Content: Measure the key dimensions of the valve, including the connection port, valve body length, valve stem diameter, etc., to ensure that it meets the design drawings and standard requirements.
Standards: International standards include ASME B16.10, ASME B16.5, ISO 5752, etc.; Chinese standards include GB/T 12221 (valve structure length), GB/T 9112 (flange connection size), etc.
Detection method: Use calipers, micrometers and other measuring tools to measure the key dimensions of the valve to ensure that they meet the design requirements.

3. Sealing performance test
Static pressure test: Apply hydrostatic pressure or air pressure to the valve, and check for leakage after maintaining it for a certain period of time.
Low-pressure air tightness test: When the valve is closed, apply low-pressure gas to the inside of the valve and check for leakage.
Shell strength test: Apply hydrostatic pressure higher than the working pressure to the valve to test its shell strength and pressure resistance.
Valve stem strength test: Evaluate whether the torque or tensile force borne by the valve stem during operation is within the safe range.

4. Operational performance test
Opening and closing torque and speed test: Test the opening and closing torque, opening and closing speed and operating feel of the valve to ensure smooth operation and within a reasonable torque range.
Flow characteristic test: Test the flow characteristics of the valve at different openings to evaluate its ability to regulate the fluid.

5. Corrosion resistance test
Evaluation content: Evaluate the corrosion resistance of the valve material to the working medium.
Standards: International standards include ISO 9227 (salt spray test), ASTM G85, etc.
Detection method: Place the valve in a salt spray test chamber to simulate the corrosive environment and test the durability of the material under corrosive conditions.

6. Durability and reliability test
Repeated opening and closing cycle test: Repeated opening and closing cycles of the valve to evaluate its durability and reliability in long-term use.
Temperature stability test: Test the performance stability of the valve under different temperature conditions to ensure its normal operation under extreme temperature environments.
Vibration and shock test: Place the valve on a vibration table or shock table to simulate the vibration and shock in the working environment and test the stability and reliability of the valve.

7. Leakage detection
Internal leakage detection: Test the internal sealing performance of the valve in the closed state.
External leakage detection: Check the external sealing of the valve in use to ensure that there is no leakage of the medium.

8. Other tests
Safety valve test: For safety valves, set pressure and return seat pressure tests are also required to ensure that they comply with the instructions and relevant regulations.