The Valve,check, cataloged under National Stock Number 4820-00-135-1641, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 24 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 4820-00-135-1641 |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Connection Style | FLARED (TUBE) SECOND END |
| Connection Style | FLARED (TUBE) FIRST END |
| Style Designator | STRAIGHT THRU |
| Nominal Outside Diameter Tube Accommodated | 0.438 INCHES SECOND END IN |
| Nominal Outside Diameter Tube Accommodated | 0.833 INCHES FIRST END IN |
| Operating Pressure | 3000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND SECOND END |
| Thread Direction | RIGHT-HAND FIRST END |
| Nominal Thread Size | 0.438 INCHES SECOND END IN |
| Nominal Thread Size | 0.500 INCHES FIRST END IN |
| Seat Angle | 37.0 DEGREES FIRST END |
| Seat Angle | 37.0 DEGREES SECOND END |
| Disk Loading Method | SPRING |
| Surface Treatment | PASSIVATE |
| Media for Which Designed | AIR SINGLE RESPONSE |
| Thread Class | 3A FIRST END A |
| Thread Class | 3A SECOND END A |
| Thread Quantity Per Inch | 20 FIRST END |
| Thread Quantity Per Inch | 20 SECOND END |
| Material | STEEL CORROSION RESISTING SEAT |
| Material | STEEL CORROSION RESISTING BODY |
| Thread Series Designator | UNF FIRST END |
| Thread Series Designator | UNF SECOND END |
| 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 |
|---|---|
| 3C2062 | 3/2 Design control — primary reference U.S. Government activity |
NSN 4820-00-135-1641 is a Valve,check, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-00-135-1641: Flow Control Device: POPPET; Connection Style: FLARED (TUBE) SECOND END; Connection Style: FLARED (TUBE) FIRST END; Style Designator: STRAIGHT THRU. 24 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.