The Valve,safety Relief, cataloged under National Stock Number 4820-00-273-9757, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 15 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-00-273-9757 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Flange Shape | ROUND WITH HOLES FIRST END |
| Flange Face Design | PLAIN FIRST END |
| Bolt Circle Nominal Diameter | 4.437 INCHES FIRST END IN |
| Connection Type | FLANGE FIRST END |
| Style Designator | ANGLE |
| Bolt Hole Nominal Diameter | 0.562 INCHES FIRST END IN |
| Operating Pressure | 100.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Valve Size | 2.000 INCHES IN |
| Maximum Operating Temp | 425.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Bolt Hole Quantity | 6 FIRST END |
| Media for Which Designed | STEAM SINGLE RESPONSE |
| Material | COPPER ALLOY BODY |
| Opening Pressure Setting | 2.0 POUNDS PER SQUARE INCH LBS |
| Valve Operation Method | AUTOMATIC |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Reference | Meaning |
|---|---|
| 2LP B135(SEC) | C/1 Advisory reference — outside the item-of-supply concept Derbyshire Machine & Tool Co |
| 5S1280ALT4 | 3/2 Design control — primary reference U.S. Government activity |
NSN 4820-00-273-9757 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-00-273-9757: Flow Control Device: DISK; Flange Shape: ROUND WITH HOLES FIRST END; Flange Face Design: PLAIN FIRST END; Bolt Circle Nominal Diameter: 4.437 INCHES FIRST END IN. 15 specifications are documented in the U.S. Government catalog.
No hazard code in the DLA record (HMIC N). Hazard information on this page is shown exactly as it appears in the DLA record.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-16.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.