The Valve,check, cataloged under National Stock Number 4820-01-233-8945, 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 10 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-233-8945 |
| Primary Part Number | 8556 3.50IN. |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | William E Williams Valve Corp |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Mounting Position | HORIZONTAL |
| Connection Type | FLANGE ALL ENDS |
| Style Designator | STRAIGHT THRU |
| Valve Size | 3.000 INCHES IN |
| Disk Loading Method | SPRING |
| Material | STEEL CORROSION RESISTING FLOW CONTROL DEVICE |
| Material | STEEL CORROSION RESISTING SEAT |
| Material | STEEL CORROSION RESISTING BODY |
| 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 |
|---|---|
| 8556 3.50IN. PRIMARY | William E Williams Valve Corp (USA) |
| Reference | Meaning |
|---|---|
| 152W-3 BWLD 3.5 | C/1 Advisory reference — outside the item-of-supply concept William E Williams Valve Corp |
NSN 4820-01-233-8945 is a Valve,check, manufactured by William E Williams Valve Corp, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-233-8945 has 1 manufacturer part number on file: 8556 3.50IN. (William E Williams Valve Corp).
Key specifications for 8556 3.50IN.: Flow Control Device: DISK; Mounting Position: HORIZONTAL; Connection Type: FLANGE ALL ENDS; Style Designator: STRAIGHT THRU. 10 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.