The Valve,diaphragm,stop, cataloged under National Stock Number 4820-01-559-4473, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Williams Controls Inc. 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 | 4820-01-559-4473 |
| Primary Part Number | WM778A1118588 |
| Item Name | Valve,diaphragm,stop |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Williams Controls Inc |
| Status | ACTIVE |
| Furnished Items and Quantity | 1 FILTER |
| Connection Style | PLAIN,OPTIONAL END(PIPE) ALL ENDS |
| Minimum Operating Temp | -40.0 CELSIUS DEGC |
| Connection Type | THREADED INTERNAL PIPE ALL ENDS |
| Style Designator | STRAIGHT THRU |
| Operating Pressure | 150.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.250 INCHES ALL ENDS IN |
| Maximum Operating Temp | 82.0 CELSIUS SINGLE RESPONSE DEGC |
| Material | ZINC ALLOY BODY |
| Thread Series Designator | NPTF 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 |
| Part Number | Manufacturer |
|---|---|
| WM778A1118588 PRIMARY | Williams Controls Inc (USA) |
NSN 4820-01-559-4473 is a Valve,diaphragm,stop, manufactured by Williams Controls Inc, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-559-4473 has 1 manufacturer part number on file: WM778A1118588 (Williams Controls Inc).
Key specifications for WM778A1118588: Furnished Items and Quantity: 1 FILTER; Connection Style: PLAIN,OPTIONAL END(PIPE) ALL ENDS; Minimum Operating Temp: -40.0 CELSIUS DEGC; Connection Type: THREADED INTERNAL 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.