Swing check valve consists of a circular disc which swings on a hinge pin. This check valve can be mounted horizontally as well as vertically. Preferred orientation is horizontal as there is tendency for disc to stay open if flow reversal occurs very slowly.
Parts of a Swing Check Valve
Typical materials of construction for each part
| Sr. | Description | Material |
| 01 | Body | ASTM A216 Gr. WCB |
| 02 | Body Seat Ring | ASTM A105 +HF* |
| 03 | Disc | ASTM A216 Gr. WCB + 13% Cr. Steel |
| 04 | Hinge | ASTM A216 Gr. WCB |
| 05 | Disc Washer | 13% Cr. Steel |
| 06 | Disc Nut | SS 304 |
| 07 | Disc Nut Pin | 13% Cr. Steel |
| 08 | Hinge Pin | 13% Cr. Steel |
| 09 | Gasket | ASTM A308 |
| 10 | Cover | ASTM A216 Gr. WCB |
| 11 | Stud | ASTM A193 Gr. B7 |
| 12 | Stud Nut | ASTM A194 Gr. 2H |
| Hinge Pin Cover | ASTM A105 | |
| Hing Pin Cover Bolt | ASTM A193 Gr. B7 | |
| Name Plate | SS 304 |
Regular swing check valve is not suitable if flow reversal is frequent as it can cause pounding and wear of disc. A composition disc is used for gritty liquids to reduce damage to the seat. An optional lever and outside weight may be offered either to assist closing or to counterbalance the disc in part, and allow opening by low-pressure fluid.
Applicable Codes and Standards
- BS1868 :
- ASME B16.34 : Pressure Temperature Ratings.
- ASME B16.10 : Face to face and end to end dimensions of valves.
- ASME B16.5 : End Flange Dimensions.
- ASME B16.47 : Flange dimensions for flanges larger than 24″ Series A and B.
- ASME B16.25 : Butt weld end dimensions.
- BS 6755 Part I : Valve inspection and testing.
- API 598 : Valve Inspection and Testing.
Body and Bonnet Materials Based on Temperature and Fluid
| Material Classification | ASTM Specification | Working Temperature |
| Carbon Teel | ASTM A216 Gr. WCB | -29 deg C to 427 deg C (-20 deg F to 800 deg F) |
| 1-1/4 Cr – 1/2 mo | ASTM A217 Gr. WC6 | -29 deg C to 593 deg C (-20 deg F to 1100 deg F) |
| 2-1/4 Cr – 1 mo | ASTM A217 Gr. WC9 | -29 deg C to 593 deg C (-20 deg F to 1100 deg F) |
| 5 Cr – 1/2 mo | ASTM A217 Gr. C5 | -29 deg C to 649 deg C (-20 deg F to 1200 deg F) |
| 9 Cr – 1 mo | ASTM A217 Gr. C12 | -29 deg C to 649 deg C (-20 deg F to 1200 deg F) |
| 9 Cr – 1 mo – 1/4 V | ASTM A217 Gr. C12A | -29 deg C to 649 deg C (-20 deg F to 1200 deg F) |
| Low-temperature Steel | ASTM A352 Gr. LCB/LCC | -46 deg C to 343 deg C (-50 deg F to 650 deg F) |
| Austenitic Stainless Steel / 18-8 (Type-304) | ASTM A351 Gr. CF8 | -196 deg C to 649 deg C (-320 deg F to 1200 deg F) |
| Austenitic Stainless Steel / 16Cr – 12ni – 2 mo (Type 316) | ASTM A351 Gr. CF8M | -196 deg C to 649 deg C (-320 deg F to 1200 deg F) |
Body Gasket Materials / Type based on Rating
| Rating | Typical | Optional |
| 150 | Spirally-wound SS 304 with Graphite filler | Spirally Wond SS 316 with Graphite Filler / Spirally wound SS 304/SS 316 with PTFE filler |
| 300 | Spirally-wound SS 304 with Graphite filler | Spirally Wond SS 316 with Graphite Filler / Spirally wound SS 304/SS 316 with PTFE filler |
| 600 | Spirally-wound SS 304 with Graphite filler | Octagonal Ring Type (RTJ) metal gasket in soft iron / Octagonal Ring Type (RTJ) metal gasket in SS 304 / SS 316 |
| 900 | Octagonal Ring Type (RTJ) metal gasket in soft iron | Octagonal Ring Type (RTJ) metal gasket in SS 304 / SS 316 |
| 1500 | Octagonal Ring Type (RTJ) metal gasket in soft iron | Octagonal Ring Type (RTJ) metal gasket in SS 304 / SS 316 |
Photos
Swing Check Valve
Swing Check Valve
