The Valve,safety Relief, cataloged under National Stock Number 4820-00-591-5331, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 16 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 4820-00-591-5331 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Nominal Pipe Size Accommodated | 0.500 INCHES SECOND END IN |
| Nominal Pipe Size Accommodated | 0.500 INCHES FIRST END IN |
| Connection Style | PLAIN (PIPE) SECOND END |
| Supplementary Features | SOLDER WITH ITEM USING MINIMUM AMOUNT OF HEAT POSSIBLE; WRAP BODY OF VALVE WITH WET CLOTH BEFORE APPLYING HEAT |
| Connection Type | THREADED INTERNAL PIPE FIRST END |
| Connection Type | THREADED EXTERNAL PIPE SECOND END |
| Style Designator | STRAIGHT THRU |
| Thread Direction | RIGHT-HAND SECOND END |
| Thread Direction | RIGHT-HAND FIRST END |
| Disk Loading Method | SPRING |
| Material | COPPER ALLOY BODY |
| Material | COPPER ALLOY FLOW CONTROL DEVICE |
| Material | COPPER ALLOY SEAT |
| Opening Pressure Setting | 120.0 POUNDS PER SQUARE INCH LBS |
| Valve Discharge Flow Rate | 10.0 GALLONS PER MINUTE |
| 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 |
|---|---|
| 12C506M1 | 3/2 Design control — primary reference U.S. Government activity |
| RV51-164 | 5/2 Secondary reference U.S. Government activity |
NSN 4820-00-591-5331 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-00-591-5331: Flow Control Device: POPPET; Nominal Pipe Size Accommodated: 0.500 INCHES SECOND END IN; Nominal Pipe Size Accommodated: 0.500 INCHES FIRST END IN; Connection Style: PLAIN (PIPE) SECOND END. 16 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.