旋启式止回阀的采用内装摇臂旋启式结构，阀门的所有启闭件都装于阀体内部，不穿透阀体，除了中法兰部位用密封垫片和密封环外，整体没有外漏点，杜绝阀门外泄的可能。 旋启式止回阀摇臂和阀瓣连接处采用球面连接的结构，使得阀瓣在360度范围内有一定的自由度，有适当的微量位置补偿。适用于清净介质，不宜用于含有固体颗粒和粘度较大的介质。
旋启式止回阀结构与特点
1、选材考究，符合国内、外相关标准，材料的全面质量高。
2、密封副配对先进合理，阀瓣、阀座密封面采用铁基合金或司太立（Stellite）钴基硬质合金堆焊面成，耐磨、耐高温、耐腐蚀、抗擦伤性能好，使用寿命长。
3、可采用各种配管法兰标准及法兰密封型式，满足各种工程需要及用户要求。
4、阀体材料品种齐全，垫片可根据实际工况或用户要求合理选配，能适用于各种压力、温度及介质工况。
应用规范
1、设计制造按ASME B16.34
2、结构长度按ASME B16.10
3、法兰型式及尺寸ASME B16.5
4、阀门检查和试验按API 598
| 美标旋启式法兰止回阀 | ||||||||||
| 主体外形和连接尺寸Main External and Connection Dimension | ||||||||||
| 公称压力Nominal Pressure | Size | Dimension(mm) | ||||||||
| in | d | L | D | C | g | T | t | H | n-Ø | |
| Class150Lb | 1/2" | 15 | 108 | 89 | 60.5 | 35 | 12 | 1.6 | ˉ | 4-15 |
| 3/4" | 20 | 117 | 98 | 70.0 | 43 | 12 | 1.6 | ˉ | 4-15 | |
| 1" | 25 | 127 | 108 | 79.5 | 51 | 12 | 1.6 | ˉ | 4-15 | |
| 1-1/4" | 32 | 140 | 117 | 89 | 64 | 13 | 1.6 | ˉ | 4-15 | |
| 1-1/2" | 40 | 165 | 127 | 98.5 | 73 | 15 | 1.6 | ˉ | 4-15 | |
| 2" | 50 | 203 | 152 | 120.5 | 92 | 16 | 1.6 | 161 | 4-19 | |
| 2-1/2" | 65 | 216 | 178 | 139.5 | 105 | 18 | 1.6 | 180 | 4-19 | |
| 3" | 80 | 241 | 190 | 152.5 | 127 | 19 | 1.6 | 190 | 4-19 | |
| 4" | 100 | 292 | 229 | 190.5 | 157 | 24 | 1.6 | 203 | 8-19 | |
| 5" | 125 | 330 | 254 | 216 | 186 | 24 | 1.6 | 229 | 8-22 | |
| 6" | 150 | 356 | 279 | 241.5 | 216 | 26 | 1.6 | 257 | 8-22 | |
| 8" | 200 | 495 | 343 | 298.5 | 270 | 29 | 1.6 | 292 | 8-22 | |
| 10" | 250 | 622 | 406 | 362 | 324 | 31 | 1.6 | 355 | 12-25 | |
| 12" | 300 | 698 | 483 | 432 | 381 | 32 | 1.6 | 396 | 12-25 | |
| 14" | 350 | 787 | 533 | 476 | 413 | 35 | 1.6 | 445 | 12-29 | |
| 16" | 400 | 864 | 597 | 540 | 470 | 37 | 1.6 | 490 | 16-29 | |
| 18" | 450 | 978 | 635 | 578 | 533 | 40 | 1.6 | 520 | 16-32 | |
| 20" | 500 | 978 | 698 | 635 | 584 | 43 | 1.6 | 546 | 20-32 | |
| 24" | 600 | 1295 | 813 | 749.5 | 692 | 49 | 1.6 | 880 | 20-35 | |
| 26" | 650 | 1295 | 789 | 744.5 | 711 | 41 | 1.6 | 910 | 36-22 | |
| 28" | 700 | 1448 | 837 | 795.5 | 762 | 44 | 1.6 | 935 | 40-22 | |
| 30" | 750 | 1524 | 887 | 846.0 | 813 | 44 | 1.6 | 970 | 44-22 | |
| 主要尺寸Dimensions of Flanged End | ||||||||||
| 公称压力Nominal Pressure | Size | Dimension(mm) | ||||||||
| in | d | L | D | C | g | T | t | H | n-Ø | |
| Class300Lb | 1/2" | 15 | 152 | 95 | 66.5 | 35 | 15 | 1.6 | ˉ | 4-15 |
| 3/4" | 20 | 178 | 117 | 82.5 | 43 | 16 | 1.6 | ˉ | 4-19 | |
| 1" | 25 | 203 | 124 | 89 | 51 | 18 | 1.6 | ˉ | 4-19 | |
| 1-1/4" | 32 | 216 | 133 | 98.5 | 63 | 19 | 1.6 | ˉ | 4-19 | |
| 1-1/2" | 40 | 229 | 156 | 114.5 | 73 | 21 | 1.6 | ˉ | 4-22 | |
| 2" | 50 | 267 | 165 | 127 | 92 | 22 | 1.6 | 178 | 8-19 | |
| 2-1/2" | 65 | 292 | 190 | 149 | 105 | 25 | 1.6 | 190 | 8-22 | |
| 3" | 80 | 318 | 210 | 168 | 127 | 29 | 1.6 | 216 | 8-22 | |
| 4" | 100 | 356 | 254 | 200 | 157 | 32 | 1.6 | 241 | 8-22 | |
| 5" | 125 | 400 | 279 | 235 | 186 | 35 | 1.6 | 267 | 8-22 | |
| 6" | 150 | 444 | 318 | 270 | 216 | 37 | 1.6 | 305 | 12-22 | |
| 8" | 200 | 533 | 381 | 330 | 270 | 41 | 1.6 | 368 | 12-25 | |
| 10" | 250 | 622 | 444 | 387.5 | 324 | 48 | 1.6 | 394 | 16-29 | |
| 12" | 300 | 711 | 521 | 451 | 381 | 51 | 1.6 | 445 | 16-32 | |
| 14" | 350 | 838 | 584 | 514.5 | 413 | 54 | 1.6 | 470 | 20-32 | |
| 16" | 400 | 864 | 648 | 571.5 | 470 | 57 | 1.6 | 533 | 20-35 | |
| 18" | 450 | 978 | 711 | 628.5 | 533 | 60 | 1.6 | 584 | 24-35 | |
| 20" | 500 | 1016 | 775 | 686 | 584 | 64 | 1.6 | 610 | 24-35 | |
| 24" | 600 | 1346 | 914 | 813 | 692 | 70 | 1.6 | 900 | 24-41 | |
| Class600Lb | 2" | 50 | 292 | 165 | 127 | 92 | 33 | 6.4 | 203 | 8-19 |
| 2-1/2" | 65 | 330 | 190 | 149 | 105 | 36 | 6.4 | 229 | 8-22 | |
| 3" | 80 | 356 | 210 | 168 | 127 | 39 | 6.4 | 235 | 8-22 | |
| 4" | 100 | 432 | 273 | 216 | 157 | 45 | 6.4 | 286 | 8-25 | |
| 5" | 125 | 508 | 330 | 266.5 | 186 | 52 | 6.4 | 292 | 8-29 | |
| 6" | 150 | 559 | 356 | 292 | 216 | 55 | 6.4 | 330 | 12-29 | |
| 8" | 200 | 660 | 419 | 349 | 270 | 63 | 6.4 | 381 | 12-32 | |
| 10" | 250 | 787 | 508 | 432 | 324 | 71 | 6.4 | 457 | 16-35 | |
| 12" | 300 | 838 | 559 | 489 | 381 | 74 | 6.4 | 584 | 20-35 | |
| 14" | 350 | 889 | 603 | 527 | 413 | 77 | 6.4 | 635 | 20-38 | |
| 16" | 400 | 991 | 686 | 603 | 470 | 84 | 6.4 | 684 | 20-41 | |
| 18" | 450 | 1092 | 743 | 654 | 533 | 90 | 6.4 | 752 | 20-44 | |
| 20" | 500 | 1194 | 813 | 724 | 584 | 96 | 6.4 | 975 | 24-44 | |
