Butterfly check valve refers to the valve that automatically opens and closes the valve disc depending on the flow of the medium itself to prevent the backflow of the medium. It is also known as check valve, one-way valve, backflow valve and back pressure valve. The check valve belongs to an automatic valve, which is mainly used to prevent medium backflow, reverse rotation of pump and driving motor, and discharge of container medium. The check valve can also be used on the pipeline to supply the auxiliary system in which the pressure may rise above the system pressure. Check valves can be mainly divided into swing check valve (rotating according to the center of gravity), lift check valve (moving along the axis) and butterfly check valve (rotating along the center).
Design and Manufacture | API 594 |
Face to Face | ASME/ANSI B16.1 |
Flange End | ASME/ANSI B16.5 |
Inspection | API 598 |
DH77X/H-150LB | DH77H/X-300LB | ||||||||
NPS(inch) | L(mm) | D(mm) | D2(mm) | D3(mm) | NPS(inch) | L(mm) | D(mm) | D2(mm) | D3(mm) |
2 | 60 | 103 | 51 | 56 | 2 | 60 | 110 | 51 | 58 |
21/2 | 67 | 122 | 65 | 72 | 21/2 | 67 | 128 | 65 | 73 |
3 | 73 | 135 | 80 | 88 | 3 | 73 | 147 | 80 | 88 |
4 | 73 | 193 | 102 | 108 | 4 | 73 | 179 | 102 | 108 |
5 | 86 | 195 | 127 | 132 | 5 | 86 | 214 | 127 | 132 |
6 | 97 | 220 | 152 | 160 | 6 | 98 | 249 | 152 | 160 |
8 | 127 | 277 | 203 | 210 | 8 | 127 | 305 | 203 | 210 |
10 | 146 | 337 | 254 | 266 | 10 | 146 | 359 | 254 | 266 |
12 | 181 | 407 | 305 | 310 | 12 | 181 | 420 | 305 | 310 |
14 | 184 | 448 | 350 | 355 | 14 | 222 | 483 | 350 | 355 |
16 | 191 | 512 | 400 | 405 | 16 | 232 | 537 | 400 | 405 |
18 | 203 | 547 | 450 | 455 | 18 | 264 | 594 | 450 | 455 |
20 | 219 | 604 | 500 | 505 | 20 | 292 | 652 | 500 | 505 |
24 | 222 | 715 | 600 | 605 | 24 | 318 | 772 | 600 | 608 |
28 | 305 | 773 | 700 | 700 | 30 | 368 | 882 | 735 | 740 |
30 | 305 | 824 | 746 | 750 |
1 both ends of the valve passage must be blocked and there is a dry and ventilated room. If it is stored for a long time, the rust prevention shall be checked frequently.
2 before installation, the valve shall be cleaned and the defects caused during transportation shall be eliminated.
3 during installation, carefully check whether the marks and nameplates on the valve meet the use requirements.
4 the valve is installed on the horizontal pipeline with the valve cover upward.
1. Do not make the check valve bear weight in the pipeline. The large check valve should be supported independently to prevent it from being affected by the pressure generated by the pipe system.
2. During installation, pay attention that the direction of medium flow shall be consistent with the arrow direction of the valve body.
3. Lift type vertical disc check valves shall be installed on vertical pipes.
4. Lift type horizontal disc check valve shall be installed on horizontal pipeline