The Valve,safety Relief, cataloged under National Stock Number 4820-01-520-6531, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 13 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 4820-01-520-6531 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | PISTON |
| Connection Type | THREADED INTERNAL PIPE FIRST END |
| Connection Type | THREADED INTERNAL PIPE SECOND END |
| Style Designator | ANGLE |
| Thread Direction | RIGHT-HAND SECOND END |
| Thread Direction | RIGHT-HAND FIRST END |
| Nominal Thread Size | 0.750 INCHES SECOND END IN |
| Nominal Thread Size | 0.750 INCHES FIRST END IN |
| Disk Loading Method | SPRING |
| Material | STEEL OVERALL |
| Thread Series Designator | NPT SECOND END |
| Thread Series Designator | UNF FIRST END |
| 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 |
|---|---|
| SVS4060RVWSPG | 3/9 Design control — primary reference Ruthman Pump and Engineering Inc Dba Fulflo Specialties Co Div Fulflo Specialties Co. |
| 53045 | 5/2 Secondary reference U.S. Government activity |
NSN 4820-01-520-6531 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-01-520-6531: Flow Control Device: PISTON; Connection Type: THREADED INTERNAL PIPE FIRST END; Connection Type: THREADED INTERNAL PIPE SECOND END; Style Designator: ANGLE. 13 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.