The Valve,check, cataloged under National Stock Number 4820-01-081-3983, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 18 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 4820-01-081-3983 |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Connection Style | PLAIN (TUBE) FIRST END |
| Mounting Position | HORIZONTAL OR VERTICAL |
| Connection Type | THREADED EXTERNAL TUBE FIRST END |
| Connection Type | THREADED EXTERNAL TUBE SECOND END |
| Style Designator | STRAIGHT THRU |
| Thread Direction | RIGHT-HAND SECOND END |
| Thread Direction | RIGHT-HAND FIRST END |
| Nominal Thread Size | 0.437 INCHES SECOND END IN |
| Nominal Thread Size | 0.562 INCHES FIRST END IN |
| Seat Angle | 12.0 DEGREES SECOND END |
| Thread Class | 3A FIRST END A |
| Thread Class | 3A SECOND END A |
| Thread Quantity Per Inch | 20 FIRST END |
| Material | STEEL CORROSION RESISTING BODY |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) SECOND END |
| Thread Series Designator | UNJS FIRST END |
| Valve Operation Method | AUTOMATIC |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL Q — CCL Item — Commerce Control List |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Reference | Meaning |
|---|---|
| 2775640-101 | 1/2 Source control — Government-approved source U.S. Government activity |
| 4C3066 | 3/2 Design control — primary reference U.S. Government activity |
NSN 4820-01-081-3983 is a Valve,check, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-01-081-3983: Flow Control Device: POPPET; Connection Style: PLAIN (TUBE) FIRST END; Mounting Position: HORIZONTAL OR VERTICAL; Connection Type: THREADED EXTERNAL TUBE FIRST END. 18 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.
NSN 4820-01-081-3983 has DEMIL Code Q. Demilitarization may be required before disposal or transfer to non-military entities.
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.