止回阀属于自动阀类，主要用于介质单向流动的管道上，只允许介质向一个方向流动，以防止发生事故。本类阀门在管道中一般应当水平安装.
主要技术参数：
| NO. | Part Name | CS to ASTM | AS to ASTM | SS to ASTM | |
| Type A105 | Type F22 | Type F304(L) | Type F316(L) | ||
| 1 | Body | A105 | A182 F22 | A182 F304(L) | A182 F316(L) |
| 2 | Seat | A276 410 | A276 304 | A276 304(L) | A276 316(L) |
| 3 | Swing Disc | A276 420 | A276 304 | A276 304(L) | A276 316(L) |
| 4 | Nut | A194 2H | A194 4 | A194 8 | A194 8M |
| 5 | Hinge | A105 | A182 F22 | A182 F304 L | A182 F316(L) |
| 6 | Pin | A276 420 | A182 F304 | A182 F316 | |
| 7 | Pontlevis | A105 | A182 F22 | A182 F304 L | A182 F316(L) |
| 8 | Gasket | Corrugated SS + graphite | SS + PTFE | ||
| 9 | Bonnet | A105 | A182 F22 | A182 F304 L | A182 F316(L) |
| 10 | Bolt | A193 B7 | A193 B16 | A193 B8M | A193 B8M |
| Suitable Medium | W.O.G.etc | W.O.G.etc | HNO3,CH3OOH etc | ||
| Suitable Temperature | -29~425 | -29~550 | -29~180 | ||
