Pilot-Operated Relief Valve -- API 526/527 Natural Gas Service
Technical Datasheet -- PORV for Gas Pipeline Overpressure Protection
Document No.SV-DATA-PORV-001
RevisionA
DateMay 2026
ManufacturerSupreme Valves India, Ahmedabad, Gujarat, India
Pilot-operated relief valves (PORV) for natural gas pipeline overpressure protection. Spring-loaded main valve with external pilot control provides precise pressure sensing, fast response, and bubble-tight shutoff. Compliant with API 526 (flanged steel pressure relief valves) and API 527 (seat tightness).
Technical Specifications
| Parameter | Specification |
|---|
| Product Type | Pilot-Operated Relief Valve (PORV) |
| Category | Safety & Relief Valves |
| Size Range | 2" (DN50) -- other sizes on request |
| Pressure Class | Class 150 RF per ASME B16.5 |
| End Connections | Raised Face (RF) Flanged per ASME B16.5 |
| Flow Rating | Up to 1 MMSCFD (customisable per orifice size) |
| Body Material | ASTM A216 WCB Carbon Steel Casting |
| Trim Material | SS316 Stainless Steel |
| Seat Material | PTFE / SS316 Soft Seat -- bubble-tight shutoff |
| Pilot Material | SS316 Stainless Steel |
| Spring Material | Alloy Steel / Chrome-Silicon (set to purchaser specification) |
| Seat Leakage | Class VI (bubble-tight) per API 527 / ANSI/FCI 70-2 |
| Set Pressure | Factory-set and sealed per purchaser specification (typical 10--50 barg for gas distribution) |
| Blowdown | Adjustable per API 526 -- typically 4% to 7% of set pressure |
| Overpressure | 10% maximum accumulation per API 526 |
Materials of Construction
| Component | Material |
|---|
| Carbon Steel | ASTM A216 WCB, A105, A350 LF2 |
| Stainless Steel | SS304, SS316, SS316L, SS321 |
| Alloy Steel | ASTM A217 WC6, WC9, C5, C12 |
| Spring Steel | Chrome-Silicon, Inconel X-750 (high temperature) |
Testing & Inspection
| Test | Requirement |
|---|
| Testing | Hydrostatic shell test 1.5 x design pressure per API 598 / EN 12266-1; Seat leakage test 1.1 x design pressure -- zero visible leakage; Set pressure verification -- each valve individually tested and certified |
| Certification | ISO 9001:2015 QMS, EN 10204 3.1 material certificates, hydrostatic and seat test reports, set pressure verification certificate |
Applicable Standards
| Standard | Description |
|---|
| Design Standard | API 526 Flanged Steel Pressure Relief Valves, API 527 Seat Tightness |
| Service Standard | ASME B31.8 Gas Transmission and Distribution Piping Systems |
Notes
- All valves are manufactured by Supreme Valves India as per our standard specifications.
- Set pressure, blowdown, and pilot orifice size must be specified by the purchaser prior to order for factory-setting and sealing.
- Field adjustment capability is provided; however, breaking the factory seal voids the set-pressure certification.
- For sour gas service (H2S > 50 ppm), material upgrade to NACE MR0175 compliant materials (SS316L body, Inconel trim) is required.
- For high-temperature service (> 200 deg C), material upgrade to ASTM A217 WC6/WC9 body and Inconel X-750 spring is required.
- All valves are factory-tested per API 598 / EN 12266-1: hydrostatic shell test 1.5 x design pressure, seat leakage test 1.1 x design pressure (zero visible leakage for soft-seated valves).
- Each valve is individually set-pressure tested and certified. Test certificate issued per EN 10204 3.1.
