The Valve,safety Relief, cataloged under National Stock Number 4820-01-271-4797, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Safran Helicopter Engines. Government technical data includes 13 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-271-4797 |
| Primary Part Number | 8814650407 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Safran Helicopter Engines |
| Status | ACTIVE |
| Flow Control Device | SLIDE |
| Connection Style | PLAIN (PIPE) ALL ENDS |
| Connection Type | THREADED EXTERNAL PIPE ALL ENDS |
| Style Designator | STRAIGHT THRU |
| Operating Pressure | 600.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.250 INCHES ALL ENDS IN |
| Maximum Operating Temp | 250.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Material | COPPER ALLOY OVERALL |
| Thread Series Designator | NPT ALL ENDS |
| Opening Pressure Setting | 425.0 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 |
| Part Number | Manufacturer |
|---|---|
| 8814650407 | Safran Helicopter Engines (FRA) |
| Reference | Meaning |
|---|---|
| 559B2M425 | 3/2 Design control — primary reference U.S. Government activity |
NSN 4820-01-271-4797 is a Valve,safety Relief, manufactured by Safran Helicopter Engines, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-271-4797 has 1 manufacturer part number on file: 8814650407 (Safran Helicopter Engines).
Key specifications for 8814650407: Flow Control Device: SLIDE; Connection Style: PLAIN (PIPE) ALL ENDS; Connection Type: THREADED EXTERNAL PIPE ALL ENDS; Style Designator: STRAIGHT THRU. 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.