Slam-Shut Valve (SSV) -- Natural Gas Emergency Safety Shut-Off
Technical Datasheet -- Over-Pressure and Under-Pressure Safety Shut-Off Device
Document No.SV-DATA-SSV-001
RevisionA
DateMay 2026
ManufacturerSupreme Valves India, Ahmedabad, Gujarat, India
Slam-shut valves (SSV) are emergency safety shut-off devices for natural gas distribution and transmission pipelines. They automatically close the gas flow upon detection of over-pressure or under-pressure conditions, protecting downstream equipment and personnel. The self-contained mechanical trip mechanism requires no external power, instrument air, or control system.
Technical Specifications
| Parameter | Specification |
|---|
| Product Type | Slam-Shut Valve (SSV) -- Emergency Safety Shut-Off |
| Category | Gas Safety Valves |
| Size Range | 4" to 6" (DN100 to DN150) -- other sizes on request |
| Pressure Class | Class 150 RF / Class 300 RF / Class 600 RF per ASME B16.5 |
| End Connections | Raised Face (RF) Flanged per ASME B16.5 -- RTJ available on request for Class 600 |
| Flow Rating | 5 / 25 / 40 MMSCFD (size and pressure class dependent) |
| Body Material | ASTM A216 WCB (Class 150/300) -- ASTM A217 WC6 (Class 600 high temp) |
| Trim Material | SS316 Stainless Steel |
| Seat Material | PTFE / SS316 Soft Seat -- bubble-tight shutoff |
| Trip Mechanism | SS316 / Alloy Steel mechanical trip, self-contained, no external power |
| Trip Function | Over-pressure trip + Under-pressure trip (settings factory-set per purchaser spec) |
| Reset | Manual lever / handwheel after trip event |
| Response Time | < 1 second for full closure from trip signal |
Materials of Construction
| Component | Material |
|---|
| Carbon Steel | ASTM A216 WCB, A105 |
| Alloy Steel | ASTM A217 WC6, WC9 (high pressure / high temp) |
| Stainless Steel | SS304, SS316, SS316L trim |
| Seat | PTFE / RPTFE / SS316 soft seat with metal backup |
Testing & Inspection
| Test | Requirement |
|---|
| Testing | Hydrostatic shell test 1.5 x WP per API 598 / EN 12266-1; Seat leakage test 1.1 x WP -- zero visible leakage; Functional test -- full stroke, trip test, reset test; Set pressure verification -- each valve individually tested and certified |
| Certification | ISO 9001:2015 QMS, EN 10204 3.1 material certificates, functional test reports, set pressure verification certificates |
Applicable Standards
| Standard | Description |
|---|
| Design Standard | ISO 23555 Safety Shut-Off Devices for Gas Burners and Gas Appliances |
| 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.
- Over-pressure trip setting and under-pressure trip setting must be specified by the purchaser prior to order for factory-setting and mechanical locking.
- Response time (< 1 second for full closure) is verified during factory functional testing.
- For sour gas service (H2S > 50 ppm), material upgrade to NACE MR0175 compliant materials is required.
- For high-temperature service (> 200 deg C), material upgrade to ASTM A217 WC6/WC9 body 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), functional test (full stroke, trip test, reset test).
- Each valve is individually set-pressure tested and certified. Test certificate issued per EN 10204 3.1.
