止回阀是一种依靠介质本身的流动而自动启闭阀瓣用来阻止介质逆向流动的自动阀门,衬里止回阀基本类型有四种:H41型法兰连接直通升降式止回阀和H42型升降立式止回阀、H44立式止回阀、H76旋启式止回阀。
衬氟升降止回阀主要外形和连接尺寸:
| 公称通径 | 标准值 | 参考值 |
| DN（mm | NPSinch | L | D | D1 | D2 | f | b | Z-φd | B | H | WTkg |
| PN1.0MPa |
| 15 | 1/2 | 130 | 95 | 65 | 45 | 2 | 14 | 4-φ14 | 105 | 55 | 5 |
| 20 | 3/4 | 150 | 105 | 75 | 55 | 2 | 16 | 4-φ14 | 115 | 58 | 7 |
| 25 | 1 | 160 | 115 | 85 | 65 | 2 | 16 | 4-φ14 | 128 | 60 | 9 |
| 32 | 11/4 | 180 | 135 | 100 | 78 | 2 | 18 | 4-φ18 | 145 | 75 | 11 |
| 40 | 11/2 | 200 | 145 | 110 | 85 | 3 | 18 | 4-φ18 | 160 | 82 | 13.5 |
| 50 | 2 | 230 | 160 | 125 | 100 | 3 | 20 | 4-φ18 | 178 | 95 | 18 |
| 65 | 21/2 | 290 | 180 | 145 | 120 | 3 | 20 | 4-φ18 | 205 | 105 | 22 |
| 80 | 3 | 310 | 195 | 160 | 135 | 3 | 22 | 4-φ18 | 230 | 120 | 28 |
| 100 | 4 | 350 | 215 | 180 | 155 | 3 | 22 | 8-φ18 | 255 | 135 | 34 |
| 125 | 5 | 400 | 245 | 210 | 185 | 3 | 24 | 8-φ18 | 305 | 158 | 58 |
| 150 | 6 | 480 | 280 | 240 | 210 | 3 | 24 | 8-φ23 | 345 | 180 | 72 |
| 200 | 8 | 600 | 335 | 295 | 265 | 3 | 26 | 8-φ23 | 415 | 215 | 150 |
| 250 | 10 | 622 | 390 | 350 | 320 | 3 | 28 | 12-φ23 | 490 | 240 | 165 |
| 300 | 12 | 698 | 440 | 400 | 368 | 4 | 28 | 12-φ23 | 540 | 265 | 190 |
| 350 | 14 | 787 | 500 | 460 | 428 | 4 | 30 | 16-φ23 | 585 | 300 | 225 |
| 400 | 16 | 914 | 565 | 515 | 482 | 4 | 32 | 16-φ25 | 635 | 360 | 254 |
| 450 | 18 | 978 | 615 | 565 | 532 | 4 | 32 | 20-φ25 | 680 | 385 | 285 |
| 500 | 20 | 978 | 670 | 620 | 585 | 4 | 34 | 20-φ25 | 740 | 415 | 333 |