The Seat,valve, cataloged under National Stock Number 4820-01-393-9899, 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11 specifications, cited from the U.S. Government catalog. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 4820-01-393-9899 |
| Item Name | Seat,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flange Seat to Disk End Height | 0.625 INCHES NOMINAL IN |
| Flange Diameter | 1.499 INCHES NOMINAL IN |
| Seal Accommodation Type | GROOVED |
| Style Designator | THREADED FLANGED |
| Body Inside Diameter | 0.375 INCHES NOMINAL IN |
| Nominal Thread Size | 1.130 INCHES SINGLE THREADED PORTION IN |
| Under Flange Height | 1.187 INCHES NOMINAL IN |
| Thread Class | 2A SINGLE THREADED PORTION A |
| Thread Quantity Per Inch | A12 SINGLE THREADED PORTION |
| Thread Series Designator | UN SINGLE THREADED PORTION |
| Seating Surface Shape | FLAT |
| 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 |
|---|---|
| 134B818AB-1 | 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 |
| 134B818AB-1 | 3/9 Design control — primary reference General Electric Co Naval and Drive Turbine Systems Dept |
| 134B818AB-1 | 5/9 Secondary reference Siemens Government Technologies, Inc. Dba Sgt Dresser-Rand Div Sgt Dresser-Rand |
NSN 4820-01-393-9899 is a Seat,valve, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-01-393-9899: Flange Seat to Disk End Height: 0.625 INCHES NOMINAL IN; Flange Diameter: 1.499 INCHES NOMINAL IN; Seal Accommodation Type: GROOVED; Style Designator: THREADED FLANGED. 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.