The Valve,safety Relief, cataloged under National Stock Number 4820-00-477-1774, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 20 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-00-477-1774 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Connection Style | PLAIN,OPTIONAL END(PIPE) FIRST END |
| Connection Style | PLAIN (PIPE) SECOND END |
| Connection Type | THREADED INTERNAL PIPE FIRST END |
| Connection Type | THREADED EXTERNAL PIPE SECOND END |
| Style Designator | ANGLE |
| Features Provided | PRESSURE TIGHT OUTLET SIDE |
| Bonnet Type | INSIDE SCREW |
| Thread Direction | RIGHT-HAND SECOND END |
| Thread Direction | RIGHT-HAND FIRST END |
| Nominal Thread Size | 1.500 INCHES FIRST END IN |
| Nominal Thread Size | 1.500 INCHES SECOND END IN |
| Disk Loading Method | SPRING |
| Bonnet Attachment Method | THREADED |
| Material | COPPER ALLOY OVERALL |
| Thread Series Designator | NPT SECOND END |
| Thread Series Designator | NPT FIRST END |
| Opening Pressure Setting | 15.0 POUNDS PER SQUARE INCH LBS |
| Valve Discharge Flow Rate | 1036.0 POUNDS PER HOUR 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 |
|---|---|
| 4699N28 | 3/9 Design control — primary reference Mcmaster-Carr Supply Co |
NSN 4820-00-477-1774 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-00-477-1774: Flow Control Device: DISK; Connection Style: PLAIN,OPTIONAL END(PIPE) FIRST END; Connection Style: PLAIN (PIPE) SECOND END; Connection Type: THREADED INTERNAL PIPE FIRST END. 20 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.