The Seat,valve, cataloged under National Stock Number 4820-01-449-1979, 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10 specifications, cited from the U.S. Government catalog. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-449-1979 |
| Item Name | Seat,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Thread Length | 0.266 INCHES NOMINAL SINGLE THREADED PORTION IN |
| Style Designator | PLAIN THREADED |
| Material Document and Classification | ASTM B164 ASSN STD SINGLE MATERIAL RESPONSE OR ASTM A494 GR -30C ASSN STD SINGLE MATERIAL RESPONSE OR QQ-N-281 FED SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Body Inside Diameter | 1.318 INCHES NOMINAL IN |
| Nominal Thread Size | 1.8125 INCHES SINGLE THREADED PORTION IN |
| Thread Class | 3A SINGLE THREADED PORTION A |
| Thread Quantity Per Inch | 20 SINGLE THREADED PORTION |
| Material | NICKEL ALLOY OVERALL |
| 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 |
|---|---|
| 803-4384536-61XX-85 | 3/2 Design control — primary reference U.S. Government activity |
| 4820PL1283137 | 6/9 Informative reference only Jednolity Indeks Materialowy - Uniform Material Index |
| 4384536 | D/9 Drawing number reference only U.S. Government activity |
| 803-4384536 PC 85 | 5/2 Secondary reference U.S. Government activity |
NSN 4820-01-449-1979 is a Seat,valve, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-01-449-1979: Overall Height: 0.375 INCHES NOMINAL IN; Thread Length: 0.266 INCHES NOMINAL SINGLE THREADED PORTION IN; Style Designator: PLAIN THREADED; Material Document and Classification: ASTM B164 ASSN STD SINGLE MATERIAL RESPONSE OR ASTM A494 GR -30C ASSN STD SINGLE MATERIAL RESPONSE OR QQ-N-281 FED SPEC SINGLE MATERIAL RESPONSE OVERALL. 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.