The Valve,safety Relief, cataloged under National Stock Number 4820-01-420-5231, 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20 specifications, cited from the U.S. Government catalog. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-420-5231 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Connection Style | GASKET SEAL(BOSS) SECOND END |
| Connection Style | FLARED (TUBE) FIRST END |
| Minimum Operating Temp | -100.0 FAHRENHEIT DEGF |
| Connection Type | THREADED EXTERNAL TUBE FIRST END |
| Connection Type | THREADED INTERNAL TUBE SECOND END |
| Style Designator | STRAIGHT THRU NOTE: TO BE USED FOR VALVE BODIES OF ONE SECTION ONLY. |
| Nominal Outside Diameter Tube Accommodated | 0.250 INCHES SECOND END IN |
| Operating Pressure | 1000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.250 INCHES ALL ENDS IN |
| Seat Angle | 37.0 DEGREES FIRST END |
| Maximum Operating Temp | 400.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Media for Which Designed | WATER-OIL-GAS SINGLE RESPONSE |
| Material | STEEL CORROSION RESISTING SEAT |
| Material | STEEL COMP 303 BODY |
| Thread Series Designator | NPTF SECOND END |
| Thread Series Designator | NPT FIRST END |
| Opening Pressure Setting | 25.0 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 |
|---|---|
| ES9983-01T25 | 5/2 Secondary reference U.S. Government activity |
| ES9983 | 5/9 Secondary reference Drs Sustainment Systems, Inc. |
| 5120TP-4TJ-25 | 3/2 Design control — primary reference U.S. Government activity |
| ES9983-01T25 | 5/9 Secondary reference Drs Sustainment Systems, Inc. |
NSN 4820-01-420-5231 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-01-420-5231: Connection Style: GASKET SEAL(BOSS) SECOND END; Connection Style: FLARED (TUBE) FIRST END; Minimum Operating Temp: -100.0 FAHRENHEIT DEGF; Connection Type: THREADED EXTERNAL TUBE 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.