metallurgical valve
| structural approach | direct joint type | angle joint type | swing out type | |
| nominal diameter(dn)（mm） | dn250-dn500 | dn150-dn500 | dn250-dn400 | |
| workers said pressure (mpa) | ≤0.3 | ≤0.3 | ≤0.25 | |
| test pressure | case | 1.5 times the working pressure | 1.5 times the working pressure | |
| seal | 1.1 times the working pressure | 1.1 times the working pressure | ||
| sealing rating | a | a | ||
| on/off differential pressure（mpa） | ≤0.3 | ≤0.25 | ||
| applicable temperature（℃） | ≤250 | ≤250 | ≤250 | |
| applicable medium | half net gas, nitrogen | half net gas | gas , smoke | |