The Valve,safety Relief, cataloged under National Stock Number 4820-00-683-8922, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Superior Valve Co. Government technical data includes 19 specifications, cited from the U.S. Government catalog. The record lists 2 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 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 | 4820-00-683-8922 |
| Primary Part Number | 959B |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Superior Valve Co |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Nominal Pipe Size Accommodated | 0.250 INCHES FIRST END IN |
| Connection Style | PLAIN (PIPE) FIRST END |
| Connection Type | THREADED EXTERNAL PIPE FIRST END |
| Style Designator | ANGLE |
| Operating Pressure | 500.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Features Provided | VALVE STEM LOCK SHIELD |
| Bonnet Type | INSIDE SPRING |
| Thread Direction | RIGHT-HAND FIRST END |
| Nominal Thread Size | 0.250 INCHES FIRST END IN |
| Disk Loading Method | SPRING |
| Bonnet Attachment Method | THREADED |
| Media for Which Designed | AIR SINGLE RESPONSE |
| Material | COPPER ALLOY BODY |
| Material | COPPER ALLOY AND PLASTIC POLYAMIDE NYLON FLOW CONTROL DEVICE |
| Material | COPPER ALLOY SEAT |
| Thread Series Designator | NPT FIRST END |
| Opening Pressure Setting | 475.0 POUNDS PER SQUARE INCH LBS |
| Valve Operation Method | AUTOMATIC OR MANUAL |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
NSN 4820-00-683-8922 is a Valve,safety Relief, manufactured by Superior Valve Co, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-683-8922 has 2 manufacturer part numbers on file: 959B (Superior Valve Co), 959BC475 (Superior Valve Co).
1 possible match (shared part number, not a government interchangeability claim): 5975-00-782-0804. Verify interchangeability with system specifications before substitution.
Key specifications for 959B: Flow Control Device: DISK; Nominal Pipe Size Accommodated: 0.250 INCHES FIRST END IN; Connection Style: PLAIN (PIPE) FIRST END; Connection Type: THREADED EXTERNAL PIPE FIRST END. 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.