The Seat,valve, cataloged under National Stock Number 4820-01-449-3561, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 10 specifications, cited from the U.S. Government catalog. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-449-3561 |
| Item Name | Seat,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Thread Length | 0.218 INCHES NOMINAL SINGLE THREADED PORTION IN |
| Style Designator | PLAIN THREADED |
| Body Inside Diameter | 1.630 INCHES NOMINAL IN |
| Nominal Thread Size | 2.062 INCHES SINGLE THREADED PORTION IN |
| Thread Class | 3A SINGLE THREADED PORTION A |
| Thread Quantity Per Inch | 18 SINGLE THREADED PORTION |
| Material | NICKEL ALLOY SEAT |
| Seat Angle in Deg | 45.000 NOMINAL |
| Thread Series Designator | UNS 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 |
|---|---|
| 4384536 | D/9 Drawing number reference only U.S. Government activity |
| 803-4384536-71XX-85 | 3/2 Design control — primary reference U.S. Government activity |
| 4820PL1290496 | 6/9 Informative reference only Jednolity Indeks Materialowy - Uniform Material Index |
NSN 4820-01-449-3561 is a Seat,valve, classified under FSC 4820, Valves, Nonpowered. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 4820-01-686-3608. Verify interchangeability with system specifications before substitution.
Key specifications for 4820-01-449-3561: Overall Height: 0.438 INCHES NOMINAL IN; Thread Length: 0.218 INCHES NOMINAL SINGLE THREADED PORTION IN; Style Designator: PLAIN THREADED; Body Inside Diameter: 1.630 INCHES NOMINAL IN. 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.