The Valve,check, cataloged under National Stock Number 4820-01-337-3871, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 21 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 4820-01-337-3871 |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Connection Style | GASKET SEAL (BOSS) ALL ENDS |
| Mounting Position | HORIZONTAL OR VERTICAL |
| Connection Type | THREADED INTERNAL BOSS ALL ENDS |
| Style Designator | STRAIGHT THRU |
| Operating Pressure | 3000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.562 INCHES ALL ENDS IN |
| Maximum Operating Temp | -65.0 FAHRENHEIT FIRST RESPONSE DEGF |
| Maximum Operating Temp | 200.0 FAHRENHEIT SECOND RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Media for Which Designed | CARBON DIOXIDE FIFTH RESPONSE |
| Media for Which Designed | ACETYLENE SECOND RESPONSE |
| Media for Which Designed | AMMONIA, GASEOUS FOURTH RESPONSE |
| Media for Which Designed | AIR FIRST RESPONSE |
| Media for Which Designed | ALCOHOL, ETHYL THIRD RESPONSE |
| Thread Class | 3B ALL ENDS |
| Material | STEEL CORROSION RESISTING BODY |
| Material | RUBBER BUTADIENE-ACRYLONITRILE CLASS NBR PACKING |
| 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 |
|---|---|
| 299T-6BB | 3/2 Design control — primary reference U.S. Government activity |
NSN 4820-01-337-3871 is a Valve,check, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-01-337-3871: Flow Control Device: POPPET; Connection Style: GASKET SEAL (BOSS) ALL ENDS; Mounting Position: HORIZONTAL OR VERTICAL; Connection Type: THREADED INTERNAL BOSS ALL ENDS. 21 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.