Materials of Construction (MOC)
| Component / Part Name | Material Specification (ASTM / Wrought Designation) |
|---|---|
| Valve Body | Alloy 20 (ASTM A351 Grade CN7M) - Cast Super Stainless Steel |
| Plates / Discs (Dual-Plate) | Alloy 20 (ASTM A351 Grade CN7M) or ASTM B473 (UNS N08020) |
| Hinge Pin & Stop Pin | Alloy 20 (ASTM B473 / UNS N08020) |
| Spring (Severe Service) | Hastelloy C276 (UNS N10276) / Alloy 20 (UNS N08020) |
| Body Seat Face | Integral Alloy 20 (Metal-to-Metal) or Teflon (PTFE) / Viton-B Insert |
| Body Gasket & Washers | PTFE (Teflon) / Alloy 20 |
Technical Specifications
| Design Parameter | Specification / International Standard |
|---|---|
| Manufacturing / Design Standard | API 594 (Wafer Check Valves) / ASME B16.34 (Pressure-Temperature Ratings) |
| Inspection & Testing Standard | API 598 (Hydrostatic shell/seat testing & Pneumatic low-pressure seat test) |
| Nominal Sizing Range | NPS 2" to 24" (DN 50 to DN 600) |
| Pressure Rating Class | ASME Class 150 lbs, Class 300 lbs, Class 600 lbs |
| End Connection Type | Wafer, Lugged, or Double Flanged (to fit ASME B16.5 RF flanges) |
| Sulfide Stress Cracking Standard | Fully compliant with NACE MR0175 / ISO 15156 metallurgy criteria |
Features & Benefits
Alloy 20 Construction
UNS N08020 (Alloy 20) body and discs provide exceptional resistance to sulphuric acid, phosphoric acid, and other highly corrosive media where SS316 is inadequate.
Dual-Plate Spring-Assisted Closure
Two semi-circular plates close rapidly with spring assistance, preventing backflow and minimising water hammer compared to swing check valves.
Compact Wafer Design
Short face-to-face dimension per API 594 wafer pattern saves weight, space, and cost compared to flanged swing check or globe-type stop-check valves.
Non-Slam Operation
Rapid spring-assisted closure eliminates the slamming and vibration common in swing check valves, protecting downstream piping and equipment.
Bi-Directional Installation
Wafer design allows installation between flanges in either flow direction (note: spring direction must be correctly oriented).
US Mining & Acid Process Support Hub
This Alloy 20 dual-plate check valve is actively supplied to copper hydrometallurgy facilities and sulfuric acid dilution loops in Utah and Arizona. For specialized local engineering guides, SWIFT payment pathways, and direct DAP air-freight terms to US sites, visit our dedicated regional hub.