The Seat,valve, cataloged under National Stock Number 4820-00-993-4028, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 11 specifications, cited from the U.S. Government catalog. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-00-993-4028 |
| Item Name | Seat,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flange Seat to Disk End Height | 0.062 INCHES NOMINAL IN |
| Flange Diameter | 3.501 INCHES NOMINAL IN |
| Body Outside Diameter | 3.470 INCHES NOMINAL IN |
| Hardness Rating | 183.0 BRINELL STANDARD NOMINAL BODY |
| Style Designator | PLAIN FLANGED |
| Material Document and Classification | MIL-S-18410,CLASS B MIL SPEC SINGLE MATERIAL RESPONSE BODY |
| Body Inside Diameter | 2.125 INCHES NOMINAL IN |
| Under Flange Height | 0.688 INCHES NOMINAL IN |
| Material | COBALT ALLOY FACE |
| Material | STEEL UNS K21590 BODY |
| Seating Surface Shape | RADIAL |
| 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 |
|---|---|
| 101B209YY1 | 5/9 Secondary reference General Electric Co Naval and Drive Turbine Systems Dept |
| 101B209YY1 | 3/9 Design control — primary reference Siemens Government Technologies, Inc. Dba Sgt Dresser-Rand Div Sgt Dresser-Rand |
| 101B209YY1 | C/1 Advisory reference — outside the item-of-supply concept Curtiss-Wright Electro-Mechanical Corp Dba Steam & Air Solutions Div Curtiss-Wright Steam and Air Solutions |
NSN 4820-00-993-4028 is a Seat,valve, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-00-993-4028: Flange Seat to Disk End Height: 0.062 INCHES NOMINAL IN; Flange Diameter: 3.501 INCHES NOMINAL IN; Body Outside Diameter: 3.470 INCHES NOMINAL IN; Hardness Rating: 183.0 BRINELL STANDARD NOMINAL BODY. 11 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.