The Valve,safety Relief, cataloged under National Stock Number 4820-00-412-4291, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 28 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 4820-00-412-4291 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Furnished Items and Quantity | 1 DEFLECTOR CAP |
| Surface Treatment Document and Classification | MIL-A-86251 MIL SPEC SINGLE TREATMENT RESPONSE LOCATION NOT OTHERWISE SPECIFIED |
| Connection Style | FLARED (TUBE) ALL ENDS |
| Minimum Operating Temp | -100.0 FAHRENHEIT DEGF |
| Connection Type | THREADED EXTERNAL TUBE ALL ENDS |
| Style Designator | STRAIGHT THRU W/BAFFLE |
| Nominal Outside Diameter Tube Accommodated | 0.250 INCHES FIRST END IN |
| Operating Pressure | 200.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Adjustable Pressure Range | +60.0 TO 150.0 POUNDS PER SQUARE INCH LBS |
| Features Provided | PRESSURE TIGHT OUTLET SIDE |
| Bonnet Type | INSIDE SPRING |
| Thread Direction | RIGHT-HAND FIRST END |
| Nominal Thread Size | 0.437 INCHES FIRST END IN |
| Seat Angle | 37.0 DEGREES ALL ENDS |
| Maximum Operating Temp | 400.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Surface Treatment | ANODIZE LOCATION NOT OTHERWISE SPECIFIED |
| Bonnet Attachment Method | INTEGRAL |
| Media for Which Designed | WATER-OIL-GAS SINGLE RESPONSE |
| Thread Class | 3A FIRST END A |
| Thread Quantity Per Inch | 20 FIRST END |
| Material | ALUMINUM ALLOY BODY LINING |
| Material | ALUMINUM ALLOY BODY |
| Material | PLASTIC POLYTETRAFLUOROETHYLENE SEAT |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) ALL ENDS |
| Opening Pressure Setting | 125.0 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 |
|---|---|
| D520A4D125 | 3/2 Design control — primary reference U.S. Government activity |
| GV500KF4D125D | 7/2 Vendor item drawing reference Northrop Grumman Systems Corporation |
NSN 4820-00-412-4291 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-00-412-4291: Flow Control Device: POPPET; Furnished Items and Quantity: 1 DEFLECTOR CAP; Surface Treatment Document and Classification: MIL-A-86251 MIL SPEC SINGLE TREATMENT RESPONSE LOCATION NOT OTHERWISE SPECIFIED; Connection Style: FLARED (TUBE) ALL ENDS. 28 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.