The Valve,safety Relief, cataloged under National Stock Number 4820-00-554-7604, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 15 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-00-554-7604 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Connection Style | GASKET SEAL(BOSS) ALL ENDS |
| Connection Type | THREADED INTERNAL BOSS ALL ENDS |
| Style Designator | STRAIGHT THRU |
| Operating Pressure | 3850.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Adjustable Pressure Range | +23.0 TO 3850.0 POUNDS PER SQUARE INCH LBS |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.562 INCHES ALL ENDS IN |
| Maximum Operating Temp | 275.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Media for Which Designed | HYDRAULIC FLUID, PHOSPHATE-ESTER BASE SINGLE RESPONSE |
| Thread Class | 3B ALL ENDS |
| Thread Quantity Per Inch | 18 ALL ENDS |
| Thread Series Designator | UNF ALL ENDS |
| Valve Operation Method | AUTOMATIC |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL B — Remove Demilitarization Key Points |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Reference | Meaning |
|---|---|
| A40155A3850 | 3/2 Design control — primary reference U.S. Government activity |
| A40155A | 5/9 Secondary reference U.S. Government activity |
NSN 4820-00-554-7604 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 4820-00-633-7017. Verify interchangeability with system specifications before substitution.
Key specifications for 4820-00-554-7604: Flow Control Device: POPPET; Connection Style: GASKET SEAL(BOSS) ALL ENDS; Connection Type: THREADED INTERNAL BOSS ALL ENDS; Style Designator: STRAIGHT THRU. 15 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.
NSN 4820-00-554-7604 has DEMIL Code B. Demilitarization may be required before disposal or transfer to non-military entities.
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.