The Seat,valve, cataloged under National Stock Number 4820-01-183-0621, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 14 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-183-0621 |
| Item Name | Seat,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flange Seat to Disk End Height | 0.406 INCHES NOMINAL IN |
| Flange Diameter | 1.812 INCHES NOMINAL IN |
| Thread Length | 0.250 INCHES NOMINAL SINGLE THREADED PORTION IN |
| Seal Accommodation Type | GROOVED |
| Style Designator | THREADED FLANGED |
| Body Inside Diameter | 0.875 INCHES NOMINAL IN |
| Nominal Thread Size | 1.625 INCHES SINGLE THREADED PORTION IN |
| Under Flange Height | 0.432 INCHES NOMINAL IN |
| Thread Class | 2A SINGLE THREADED PORTION A |
| Thread Quantity Per Inch | 20 SINGLE THREADED PORTION |
| Material | STEEL CORROSION RESISTING OVERALL |
| Seat Angle in Deg | 30.000 NOMINAL |
| Thread Series Designator | UN SINGLE THREADED PORTION |
| Seating Surface Shape | ANGULAR |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Reference | Meaning |
|---|---|
| 10231-19-596 | C/1 Advisory reference — outside the item-of-supply concept Dresser Industries Inc Masoneilan North American Opns Dresser Valve and Controls Div |
| N1052-1E PIECE 2 | 3/9 Design control — primary reference Dresser Industries Inc Masoneilan North American Opns Dresser Valve and Controls Div |
NSN 4820-01-183-0621 is a Seat,valve, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-01-183-0621: Flange Seat to Disk End Height: 0.406 INCHES NOMINAL IN; Flange Diameter: 1.812 INCHES NOMINAL IN; Thread Length: 0.250 INCHES NOMINAL SINGLE THREADED PORTION IN; Seal Accommodation Type: GROOVED. 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.