The Valve,check, cataloged under National Stock Number 4820-01-288-5257, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is William E Williams Valve Corp. Government technical data includes 23 specifications, cited from the U.S. Government catalog. The record lists 2 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-288-5257 |
| Primary Part Number | B15SW-4IN |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | William E Williams Valve Corp |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Flange Shape | ROUND WITH HOLES ALL ENDS |
| Flange Face Design | PLAIN ALL ENDS |
| Bolt Circle Nominal Diameter | 7.500 INCHES ALL ENDS IN |
| Mounting Position | HORIZONTAL OR VERTICAL |
| Connection Type | FLANGE ALL ENDS |
| Style Designator | STRAIGHT THRU FLANGED ENDS |
| Bolt Hole Nominal Diameter | 0.750 INCHES ALL ENDS IN |
| Operating Pressure | 150.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM FIRST RESPONSE LBS |
| Operating Pressure | 225.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SECOND RESPONSE LBS |
| Valve Size | 4.000 INCHES IN |
| Maximum Operating Temp | 406.0 FAHRENHEIT FIRST RESPONSE DEGF |
| Maximum Operating Temp | 150.0 FAHRENHEIT SECOND RESPONSE DEGF |
| Nominal Outside Diameter | 9.000 INCHES ALL ENDS IN |
| Bolt Hole Quantity | 8 ALL ENDS |
| Face to Face Distance | 11.500 INCHES IN |
| Media for Which Designed | WATER-OIL-GAS SECOND RESPONSE |
| Media for Which Designed | STEAM FIRST RESPONSE |
| Material | COPPER ALLOY BODY |
| Material | COPPER ALLOY FLOW CONTROL DEVICE |
| Material | COPPER ALLOY SEAT |
| Valve Operation Method | AUTOMATIC |
| Nominal Thickness | 0.688 INCHES ALL ENDS IN |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
NSN 4820-01-288-5257 is a Valve,check, manufactured by William E Williams Valve Corp, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-288-5257 has 2 manufacturer part numbers on file: B15SW-4IN (William E Williams Valve Corp), 15SW-4IN (William E Williams Valve Corp).
Key specifications for B15SW-4IN: Flow Control Device: DISK; Flange Shape: ROUND WITH HOLES ALL ENDS; Flange Face Design: PLAIN ALL ENDS; Bolt Circle Nominal Diameter: 7.500 INCHES ALL ENDS IN. 23 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.