Appearance and marking inspection

Inspection content: whether the appearance of the valve has defects, such as cracks, bubbles, dents, etc.; check the logo, nameplate and surface treatment to meet the requirements.
Standards: International standards include API 598, ASME B16.34, ISO 5208, etc.; China's standards include GB/T 12224 (general requirements for steel valves), GB/T 12237 (steel ball valves for petroleum, petrochemical and related industries) and so on.
Testing method: Through visual inspection and hand inspection, determine whether there are obvious defects on the surface of the valve, and check whether the marking and nameplate information is correct.

Size measurement

Inspection content: Measure the key dimensions of the valve, including connection ports, body length, stem diameter, etc., to ensure that it meets the design drawings and standard requirements.
Standards: international standards including ASME B16.10, ASME B16.5, ISO 5752, etc.; China's standards including GB/T 12221 (valve structure length), GB/T 9112 (flange connection size), etc..
Testing method: Use calipers, micrometers and other measuring tools to measure the key dimensions of the valve to ensure compliance with design requirements.

Sealing performance test

Static pressure test: apply hydrostatic pressure or hydrostatic pressure to the valve, maintain a certain period of time to check the leakage.
Low-pressure gas tightness test: In the case of valve closure, apply low-pressure gas to the inside of the valve, and check the leakage.
Shell strength test: Apply hydrostatic pressure higher than the working pressure to the valve and test its shell strength and pressure resistance.
Stem Strength Test: Evaluate whether the torque or tensile force that the valve stem is subjected to during operation is within safe limits.

Operation performance test

Opening and closing torque and speed test: test the valve's opening and closing torque, opening and closing speed and operating feel to ensure smooth operation and within a reasonable range of torque.
Flow characteristics test: test the flow characteristics of the valve at different openings to assess its ability to regulate the fluid.

Corrosion resistance test

Evaluation content: assess the corrosion resistance of the valve material to the working medium.
Standards: International standards including ISO 9227 (salt spray test), ASTM G85, etc..
Testing method: the valve is placed in a salt spray test chamber to simulate a corrosive environment, testing the durability of the material under corrosive conditions.

Durability and reliability test

Repeated opening and closing cycle test: Repeated opening and closing cycles of the valve to assess its durability and reliability in long-term use.
Temperature stability test: test the stability of the valve's performance in different temperature conditions to ensure that it works properly in extreme temperature environments.
Vibration and shock test: the valve is placed on the vibration table or shock table, simulating the vibration and shock in the working environment, testing the stability and reliability of the valve.

Ieakage detection

Internal leakage test: test the valve in the closed state of the internal sealing performance.
External leakage test: check the external sealing of the valve in use to ensure that no media leakage.

Other tests

Safety valve test: for safety valves, also need to be rectified pressure and return pressure and other tests to ensure that it complies with the instructions and the provisions of the relevant regulations.