Core design and manufacturing standards
ASME B16.34
General basic standard for valves: Provide pressure-temperature ratings, material selection, wall thickness calculation and acceptance conditions for ball valves, covering Class 150~2500 pressure ratings.
Key requirements:
Minimum wall thickness of the valve body to meet the high-pressure fluid impact (such as Class 600 valves need to withstand ≥ 10MPa static pressure);
Sealing surface hardness needs to be higher than the seat material to ensure bi-directional zero leakage.
ASME B16.10
Valve structure length: standardised flanged ball valve end face spacing (such as DN50 ball valve structure length 127mm), to ensure pipeline compatibility.
ASME B16.25
Welding end specification: the bevel angle (37.5 ° ± 2.5 °) and blunt edge size of the butt-welding end of the ball valve, to protect the welding strength.
Pressure rating and size comparison
| Pressure Rating | Nominal pressure (PN) | Applicable working conditions |
|---|---|---|
| Class 150 | PN20 | Low pressure water/steam systems(≤2MPa) |
| Class 300 | PN50 | Medium Pressure Chemical Piping(≤5MPa) |
| Class 600 | PN100 | High temperature oil and gas transport(≤10MPa) |
The key performance test requirements
Shell strength test
Test pressure ≥ 1.5 times the nominal pressure, holding time ≥ 10 minutes without leakage.
Sealing performance test
Low-pressure gas sealing (0.6MPa) and high-pressure water sealing (1.1 times the nominal pressure) double verification.
Fire resistance test
In accordance with API 607/6FA: sealing is maintained after 30 minutes of flame burning at 650°C (mandatory for oil and gas applications).
Other standards of synergistic application
Linkage with API standards: high-pressure ball valves need to meet the requirements of API 6D pipeline valves at the same time (such as full bore design);
Material references ASTM: valve body commonly used ASTM A216 Gr.WCB (carbon steel) or A351 Gr.CF8M (stainless steel);
Flange matching specification: flange interface needs to comply with ASME B16.5/B16.47 size chain.