The Valve,safety Relief, cataloged under National Stock Number 4820-00-439-9807, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 27 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-00-439-9807 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Nominal Pipe Size Accommodated | 0.500 INCHES SECOND END IN |
| Nominal Pipe Size Accommodated | 0.500 INCHES FIRST END IN |
| Connection Style | PLAIN,OPTIONAL END(PIPE) FIRST END |
| Connection Style | PLAIN (PIPE) SECOND END |
| Criticality Code Justification | ZZZY |
| Connection Type | THREADED INTERNAL PIPE FIRST END |
| Connection Type | THREADED EXTERNAL PIPE SECOND END |
| Style Designator | ANGLE |
| Operating Pressure | 75.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Features Provided | PRESSURE TIGHT OUTLET SIDE |
| Bonnet Type | INSIDE SPRING |
| Thread Direction | RIGHT-HAND SECOND END |
| Thread Direction | RIGHT-HAND FIRST END |
| Nominal Thread Size | 0.500 INCHES SECOND END IN |
| Nominal Thread Size | 0.500 INCHES FIRST END IN |
| Disk Loading Method | SPRING |
| Bonnet Attachment Method | INTEGRAL |
| Media for Which Designed | OXYGEN, LIQUID SINGLE RESPONSE |
| Material | COPPER ALLOY BODY |
| Material | PLASTIC POLYTETRAFLUOROETHYLENE FLOW CONTROL DEVICE |
| Material | COPPER ALLOY STEM |
| Material | COPPER ALLOY SEAT |
| Thread Series Designator | NPT SECOND END |
| Thread Series Designator | NPT FIRST END |
| Opening Pressure Setting | 75.0 POUNDS PER SQUARE INCH LBS |
| Valve Operation Method | MANUAL OR AUTOMATIC |
| Reference Number Differentiating Characteristics | AS DIFFERENTIATED BY HYDROCARBON DECONTAMINATED FOR LIQUID-OXYGEN SERVICE |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | Y |
| Reference | Meaning |
|---|---|
| 2509CB376-2 | 3/9 Design control — primary reference U.S. Government activity |
NSN 4820-00-439-9807 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-00-439-9807: Nominal Pipe Size Accommodated: 0.500 INCHES SECOND END IN; Nominal Pipe Size Accommodated: 0.500 INCHES FIRST END IN; Connection Style: PLAIN,OPTIONAL END(PIPE) FIRST END; Connection Style: PLAIN (PIPE) SECOND END. 27 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.