The Valve,check, cataloged under National Stock Number 4820-01-256-4872, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Derbyshire Machine & Tool Co. Government technical data includes 14 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-256-4872 |
| Primary Part Number | 4325301 |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Derbyshire Machine & Tool Co |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Flange Shape | ROUND WITH HOLES ALL ENDS |
| Flange Face Design | PLAIN ALL ENDS |
| Bolt Circle Nominal Diameter | 15.250 INCHES ALL ENDS IN |
| Mounting Position | HORIZONTAL |
| Connection Type | FLANGE ALL ENDS |
| Style Designator | STRAIGHT THRU |
| Bolt Hole Nominal Diameter | 0.531 INCHES ALL ENDS IN |
| Nominal Outside Diameter | 18.000 INCHES ALL ENDS IN |
| Bolt Hole Quantity | 12 ALL ENDS |
| Material | STEEL SEAT |
| Material | STEEL FLOW CONTROL DEVICE |
| Valve Operation Method | AUTOMATIC |
| Nominal Thickness | 0.750 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 |
| Part Number | Manufacturer |
|---|---|
| 4325301 PRIMARY | Derbyshire Machine & Tool Co (USA) |
| Reference | Meaning |
|---|---|
| 511-4325301 | 5/9 Secondary reference U.S. Government activity |
| H594-2283-504 | 5/9 Secondary reference Huntington Ingalls Inc Div Newport News Shipbuilding |
NSN 4820-01-256-4872 is a Valve,check, manufactured by Derbyshire Machine & Tool Co, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-256-4872 has 1 manufacturer part number on file: 4325301 (Derbyshire Machine & Tool Co).
Key specifications for 4325301: Flow Control Device: DISK; Flange Shape: ROUND WITH HOLES ALL ENDS; Flange Face Design: PLAIN ALL ENDS; Bolt Circle Nominal Diameter: 15.250 INCHES ALL ENDS IN. 14 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.