The Valve,safety Relief, cataloged under National Stock Number 4820-01-293-2440, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 25 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 4820-01-293-2440 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Connection Style | GASKET SEAL(BOSS) SECOND END |
| Connection Style | EXTERNAL SEAT FOR GASKET SEAL (BOSS) FIRST END |
| Connection Type | THREADED EXTERNAL BOSS FIRST END |
| Connection Type | THREADED INTERNAL BOSS SECOND END |
| Style Designator | STRAIGHT THRU NOTE: TO BE USED FOR VALVE BODIES OF SEPARABLE SECTIONS. |
| Operating Pressure | 2500.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Adjustable Pressure Range | +10.0 TO 2400.0 POUNDS PER SQUARE INCH LBS |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.438 INCHES ALL ENDS IN |
| Seat Angle | 90.0 DEGREES FIRST END |
| Maximum Operating Temp | 275.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Media for Which Designed | HELIUM FIFTH RESPONSE |
| Media for Which Designed | ETHYLENE GLYCOL FOURTH RESPONSE |
| Media for Which Designed | AIR FIRST RESPONSE |
| Media for Which Designed | AMMONIA, GASEOUS SECOND RESPONSE |
| Media for Which Designed | REFRIGERANT 12 THIRD RESPONSE |
| Thread Class | 3A ALL ENDS A |
| Thread Class | 3B SECOND END |
| Thread Quantity Per Inch | 20 FIRST END |
| Material | ALUMINUM ALLOY 2024 BODY |
| Thread Series Designator | UNIFIED NATIONAL JOINT (UNJ) FIRST END |
| Thread Series Designator | UNF SECOND END |
| Opening Pressure Setting | 400.0 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 |
|---|---|
| 5177A4TB-400 | 3/2 Design control — primary reference U.S. Government activity |
| D952 PIECE 69 | 5/9 Secondary reference Rix Industries |
NSN 4820-01-293-2440 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-01-293-2440: Flow Control Device: POPPET; Connection Style: GASKET SEAL(BOSS) SECOND END; Connection Style: EXTERNAL SEAT FOR GASKET SEAL (BOSS) FIRST END; Connection Type: THREADED EXTERNAL BOSS FIRST END. 25 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.