Welded check valve has three varieties of valve bonnet designs. The first kind is bolt bonnet, which adopts fillet and groove joint and uses gasket with the material of stainless steel and flexible graphite. It can also adopts ring type joint as required. The second kind is welded bonnet,. It is welded after screw thread sealing. It can also adopt rigid welding as required. The third kind is self-sealing bonnet which connects by thread and pressure seal bonnet.
Introduction
Welded check valve open or close the disc by medium to avoid refluence of medium. It is also called as cut-off valve, one-way valve, reflux valve and back pressure valve.. Welded check valve can be classified into swing check valve (rotating with barycenter) and lift check valve (moving along with axis).
Manufacturing Specifications
Manufacturing: MSS SP-118,BS5352,ANSI/ASME B16.34
Test & Inspection: API 598
Marking: MSS SP-25
Structure
1. Full bore or reduced bore;
2. Lift check valve;
3. Ball check valve;
4. Swing check valve;
5. Using spring to assist reset;
6. Bolt bonnet, welded bonnet and self-sealing bonnet
7. Socket Welding: ANSI/ASME B16.11 8;
8. Thread(NPT): ANSI/ASME B1.20.1.
Materials
| NO. |
Components |
American Standards
Carbon Steel CS to ASTM |
American Standards
Alloy Steel AS to ASTM |
American Standards
Stainless Steel SS to ASTM |
| |
|
Type A 105 |
Type F22 |
Type F304(L) |
Type F316(L) |
| 1 |
Body |
A105 |
A182 F22 |
A182 F304(L) |
A182 F316(L) |
| 2 |
Lift valve disc |
A276 410 |
A276 304 |
A276 F304(L) |
A276 F316(L) |
| 3 |
gasket |
Corrugated SS+graphite |
SS+PTFE |
| 4 |
Bonnet |
A105 |
A182 F22 |
A182 F304(L) |
A182 F316(L) |
| 5 |
Name Plate |
|
| 6 |
Bolt |
A193 B7 |
A193 B16 |
A193 B8M |
A193 B8M |
| Applicable Medium |
Water, oil, gas, etc |
HNO3,CH3OOH, etc |
| Applicable Temperature |
-29℃~425℃ |
-29℃~550℃ |
-29℃~180℃ |
Notes: other materials based on requirements. CS=carbon steel; AS=alloy steel; SS=stainless steel
Dimensions & Weights
| Size Port |
Reduced Bore(RB) |
3/8 |
1/2 |
3/4 |
1 |
1 1/4 |
1 1/2 |
2 |
|
| NPS |
Full Bore(FB) |
|
3/8 |
1/2 |
3/4 |
1 |
1 1/4 |
1 1/2 |
2 |
| L |
150~800Lb |
79 |
79 |
92 |
111 |
120 |
152 |
172 |
200 |
| |
900~1500Lb |
111 |
111 |
111 |
130 |
152 |
172 |
220 |
220 |
| H(OPEN) |
150~800Lb |
61 |
61 |
65 |
79 |
95 |
103 |
118 |
132 |
| |
900~1500Lb |
65 |
79 |
79 |
97 |
104 |
120 |
139 |
215 |
| Weights |
Bolted |
150~800Lb |
1.4 |
1.2 |
1.5 |
3.1 |
3.9 |
5.6 |
8.9 |
12.5 |
| |
|
900~1500Lb |
1.6 |
3.4 |
3.3 |
5.5 |
6.0 |
9.2 |
12.9 |
16.2 |
| |
Welded |
150~800Lb |
1.1 |
1.0 |
1.2 |
2.9 |
3.3 |
4.9 |
8.1 |
10.9 |
| |
|
900~1500Lb |
1.3 |
3.2 |
3.1 |
4.8 |
5.4 |
8.5 |
11.2 |
14.3 |