The Valve,check, cataloged under National Stock Number 4820-01-485-4749, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is The Walworth Company. Government technical data includes 12 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 | 4820-01-485-4749 |
| Primary Part Number | W420 |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | The Walworth Company |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Connection Style | PLAIN, OPTIONAL END (PIPE) ALL ENDS |
| Mounting Position | HORIZONTAL |
| Connection Type | THREADED EXTERNAL PIPE ALL ENDS |
| Style Designator | STRAIGHT THRU |
| Operating Pressure | 200.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Maximum Operating Temp | 550.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Media for Which Designed | WATER-OIL-GAS SINGLE RESPONSE |
| Material | COPPER ALLOY BODY |
| Material | COPPER ALLOY BODY LINING |
| 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 |
|---|---|
| W420 PRIMARY | The Walworth Company (USA) |
NSN 4820-01-485-4749 is a Valve,check, manufactured by The Walworth Company, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-485-4749 has 1 manufacturer part number on file: W420 (The Walworth Company).
Key specifications for W420: Flow Control Device: DISK; Connection Style: PLAIN, OPTIONAL END (PIPE) ALL ENDS; Mounting Position: HORIZONTAL; Connection Type: THREADED EXTERNAL PIPE ALL ENDS. 12 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.