The Valve,safety Relief, cataloged under National Stock Number 4820-00-620-5597, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 19 specifications, cited from the U.S. Government catalog. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-00-620-5597 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | BALL |
| Connection Style | GASKET SEAL(BOSS) ALL ENDS |
| Connection Type | THREADED INTERNAL BOSS ALL ENDS |
| Style Designator | ANGLE |
| Nominal Outside Diameter Tube Accommodated | 0.250 INCHES ALL ENDS IN |
| Operating Pressure | 3000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Adjustable Pressure Range | +2100.0 TO 4100.0 POUNDS PER SQUARE INCH LBS |
| Features Provided | PRESSURE TIGHT OUTLET SIDE |
| Bonnet Type | PACKING RETAINING |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.437 INCHES ALL ENDS IN |
| Maximum Operating Temp | 160.0 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 | 20 ALL ENDS |
| Material | ALUMINUM ALLOY OVERALL |
| Thread Series Designator | UNF ALL ENDS |
| 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 |
|---|---|
| 4268624 | 5/2 Secondary reference U.S. Government activity |
| 21700-3900 | 3/2 Design control — primary reference U.S. Government activity |
| 4268624 | 5/9 Secondary reference The Boeing Company |
NSN 4820-00-620-5597 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-00-620-5597: Flow Control Device: BALL; Connection Style: GASKET SEAL(BOSS) ALL ENDS; Connection Type: THREADED INTERNAL BOSS ALL ENDS; Style Designator: ANGLE. 19 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.