The Valve,check, cataloged under National Stock Number 4820-00-101-7931, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Automatic Switch Company Dba Asco. Government technical data includes 19 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-00-101-7931 |
| Primary Part Number | 821580 |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Automatic Switch Company Dba Asco |
| Status | ACTIVE |
| Flow Control Device | PISTON |
| Connection Style | FLARELESS SECOND END |
| Connection Style | FLARED (TUBE) FIRST END |
| Style Designator | STRAIGHT THRU |
| Nominal Outside Diameter Tube Accommodated | 0.375 INCHES SECOND END IN |
| Nominal Outside Diameter Tube Accommodated | 0.375 INCHES FIRST END IN |
| Operating Pressure | 600.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND SECOND END |
| Thread Direction | RIGHT-HAND FIRST END |
| Nominal Thread Size | 0.562 INCHES SECOND END IN |
| Nominal Thread Size | 0.562 INCHES FIRST END IN |
| Seat Angle | 37.0 DEGREES FIRST END |
| Seat Angle | 12.0 DEGREES SECOND END |
| Thread Class | 3A FIRST END A |
| Thread Class | 3A SECOND END A |
| Thread Quantity Per Inch | 18 FIRST END |
| Thread Series Designator | UNF FIRST END |
| Thread Series Designator | UNF SECOND END |
| 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 |
| Part Number | Manufacturer |
|---|---|
| 821580 PRIMARY | Automatic Switch Company Dba Asco (USA) |
NSN 4820-00-101-7931 is a Valve,check, manufactured by Automatic Switch Company Dba Asco, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-101-7931 has 1 manufacturer part number on file: 821580 (Automatic Switch Company Dba Asco).
Key specifications for 821580: Flow Control Device: PISTON; Connection Style: FLARELESS SECOND END; Connection Style: FLARED (TUBE) FIRST END; Style Designator: STRAIGHT THRU. 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.