Pressure Relief Valve, Pilot-Operated, 3 in × 300# RF, 740 psi, Sour Service
3 in × 300# RF pilot-operated PRV, 740 psi sour-service per API 526. Tight-setpoint protection for sour-gas processing systems.
Key features
- Valve Type: Pressure Relief
- Nominal Size: 3 in
- Working Pressure: 740 psi
- End Connection (Inlet): 3 in 300# ANSI Raised-Face Flange
- Service Class: Sour (NACE MR0175)
- Valve Type
- Pressure Relief
- Nominal Size
- 3 in
- Working Pressure
- 740 psi
- Pressure Class
- ANSI 300
- End Connection (Inlet)
- 3 in 300# ANSI Raised-Face Flange
- Service Class
- Sour (NACE MR0175)
Product description
The Pressure Relief Valve, Pilot-Operated, 3 in × 300# RF, 740 psi, Sour Service is a pilot-operated pressure relief valve rated for 740 psi working pressure (ANSI 300 class), 3 in 300# ANSI Raised-Face Flange. NACE MR0175 / ISO 15156 sour-service compliant.
Pilot-operated relief design — a pilot valve senses line pressure and modulates the dome pressure on the main valve. Modulating action gives a tighter setpoint band (within 3-5% of set) and chatter-free operation across the full discharge range. Suitable for tight-shutoff service on gas / vapour lines and for installations where multiple relief valves operate in parallel.
Set pressure is made-to-order. Specify the required set pressure on the RFQ — typical setpoints range from 50% to 100% of the body pressure rating. Indus calibrates and seals the valve at the spec'd setpoint with a witness-test certificate.
Construction
- Type: Pressure Relief — Pilot-Operated
- Nominal size: 3 in
- Body material: Cast WCB carbon steel — NACE MR0175 compliant
- Trim (disc + seat + nozzle): 316SS disc + nozzle, NACE-compliant Inconel X-750 spring
- Seal / soft goods: PEEK back-up + HNBR primary seals
- Inlet: 3 in 300# ANSI Raised-Face Flange
- Outlet: 4 in 150# ANSI Raised-Face Flange
Performance
Working pressure 740 psi. Set pressure factory-calibrated and witness-tested per API 526. NACE MR0175 / ISO 15156 sour-service compliant — material class EE.
Applications
- Sour-gas processing equipment protection
- Amine treatment plant relief
- Acid-gas separator over-pressure
- API 526 stamped relief installations
Compliance
- API 526 (steel pressure relief valves) and / or ASME Section VIII Division 1
- NACE MR0175 / ISO 15156 (sour-service)
- Calibration and witness-test certificate at specified set pressure
- Mill test reports per EN 10204 3.1 / 3.2
How to order
Confirm (a) line operating pressure (typically 90% of set pressure), (b) required set pressure (the over-pressure protection threshold), (c) line fluid and temperature (affects orifice sizing per API 520), (d) discharge routing (atmosphere / relief header / closed flare), (e) service class (standard vs sour), (f) any required certifications (ASME UV stamp, API monogram, witness-test attendance). Indus quotes ex-works OEM with calibration and pre-shipment test certificates.
Companion products
Pair with a matched-rated isolation valve upstream (typically a manual gate or ball valve, locked-open) and a manual block valve on the discharge line for service / maintenance access. For relief headers handling H₂S, ensure the discharge piping is also NACE MR0175 compliant. Indus also supplies relief-system engineering services (orifice sizing per API 520, blowdown / over-pressure analysis) on request.
Identification
| Parameter | Value |
|---|---|
| Valve Type | Pressure Relief |
Dimensions
| Parameter | Value |
|---|---|
| Nominal Size | 3 in |
| End Connection (Inlet) | 3 in 300# ANSI Raised-Face Flange |
| End Connection (Outlet) | 4 in 150# ANSI Raised-Face Flange |
| Bore Type | Standard |
Performance
| Parameter | Value |
|---|---|
| Working Pressure | 740 psi |
| Pressure Class | ANSI 300 |
| Service Class | Sour (NACE MR0175) |
Compliance
| Parameter | Value |
|---|---|
| API Specification | API 526 |
| PSL Class | N/A |
| PR Class | N/A |
| Material Class (API 6A) | EE |
Construction
| Parameter | Value |
|---|---|
| Body Material | Cast WCB carbon steel — NACE MR0175 compliant |
| Trim Material | 316SS disc + nozzle, NACE-compliant Inconel X-750 spring |
| Seal / Elastomer Material | PEEK back-up + HNBR primary seals |
Shipping & lead time
What is the working pressure rating?▾
How is the set pressure configured?▾
What is the difference between spring-loaded and pilot-operated PRVs?▾
What end connections does this valve use?▾
Is this valve suitable for sour-service (H₂S) wells?▾
What standards does this PRV comply with?▾
How is this PRV sized for my line?▾
What is the lead time?▾
Shipped worldwide from our Dubai warehouse. Transit, routes and documentation for 126 destinations