Dual-Plate Wafer Check Valve -- Alloy 20 Class 150
Technical Datasheet -- Corrosion-Resistant Non-Return Valve for Chemical Service
Document No.SV-DATA-DPCV-AL20-001
RevisionA
DateMay 2026
ManufacturerSupreme Valves India, Ahmedabad, Gujarat, India
Dual-plate wafer check valves in Alloy 20 (UNS N08020) for highly corrosive chemical processing applications. The spring-assisted dual-plate design provides rapid non-slam closure, protecting downstream equipment from backflow and water hammer. Compact wafer face-to-face dimension per API 594 minimises weight and installation space.
Technical Specifications
| Parameter | Specification |
|---|
| Product Type | Dual-Plate Wafer Check Valve |
| Category | Non-Return Valves |
| Size Range | 2" to 24" (DN50 to DN600) -- other sizes on request |
| Pressure Class | Class 150 per ASME B16.5 |
| End Connections | Wafer type -- fits between ASME B16.5 Class 150 flanges |
| Body Material | Alloy 20 (UNS N08020) ASTM A351 CN7M |
| Disc Material | Alloy 20 (UNS N08020) with SS316 spring |
| Seat Material | Alloy 20 integral seat with SS316 spring-assisted closure |
| Spring Material | SS316 Stainless Steel (Inconel X-750 for high temperature) |
| Hinge / Pin | SS316 or Alloy 20 |
| Face-to-Face | API 594 short pattern (compact wafer design) |
| Leakage Class | API 598 / EN 12266-1 -- metal seat standard leakage |
| Temperature Range | -29 deg C to +260 deg C (SS316 spring) -- up to +425 deg C with Inconel spring |
| Non-Slam Feature | Spring-assisted dual-plate closure minimises water hammer and reverse-flow damage |
Materials of Construction
| Component | Material |
|---|
| Alloy 20 | UNS N08020, ASTM A351 CN7M -- excellent resistance to sulphuric acid |
| Stainless Steel | SS316 springs, pins, and hinge components |
| Inconel | X-750 springs for high-temperature service |
Testing & Inspection
| Test | Requirement |
|---|
| Testing | Hydrostatic shell test 1.5 x WP per API 598; Seat leakage test per API 598 / EN 12266-1; Functional test -- spring response, plate swing, non-slam closure |
| Certification | ISO 9001:2015 QMS, EN 10204 3.1 material certificates (with PMI), hydrostatic and seat test reports |
Applicable Standards
| Standard | Description |
|---|
| Design Standard | API 594 Dual-Plate Check Valves, ASME B16.10 face-to-face |
Notes
- All valves are manufactured by Supreme Valves India as per our standard specifications.
- Alloy 20 (UNS N08020) is recommended for sulphuric acid, phosphoric acid, and nitric acid service where SS316 is inadequate.
- Spring material (SS316 vs Inconel X-750) should be selected based on operating temperature.
- For high-temperature service (> 260 deg C), Inconel X-750 springs and graphite packing are required.
- All valves are factory-tested per API 598: hydrostatic shell test 1.5 x design pressure, seat leakage test per API 598 / EN 12266-1, functional test (spring response, plate swing, non-slam closure).
