The Seat,valve, cataloged under National Stock Number 4820-01-345-5677, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 6 specifications, cited from the U.S. Government catalog. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-345-5677 |
| Item Name | Seat,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flange Diameter | 4.750 INCHES NOMINAL IN |
| Body Outside Diameter | 4.000 INCHES NOMINAL IN |
| Under Flange Height | 1.500 INCHES NOMINAL IN |
| Material | STEEL COMP 410 OVERALL |
| Seat Angle in Deg | 50.000 NOMINAL |
| 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 |
|---|---|
| 3004G56-004 | C/1 Advisory reference — outside the item-of-supply concept General Electric Company |
| 003004G56-4 | 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 |
| 003004G56-4 | 3/9 Design control — primary reference Siemens Government Technologies, Inc. Dba Sgt Dresser-Rand Div Sgt Dresser-Rand |
| 3004G56 | D/9 Drawing number reference only General Electric Company |
| 3004G56PC4 | 5/9 Secondary reference General Electric Company |
NSN 4820-01-345-5677 is a Seat,valve, classified under FSC 4820, Valves, Nonpowered. Status: active.
2 possible matches (shared part number, not a government interchangeability claim): 4820-01-346-0617, 4820-01-346-0618. Verify interchangeability with system specifications before substitution.
Key specifications for 4820-01-345-5677: Flange Diameter: 4.750 INCHES NOMINAL IN; Body Outside Diameter: 4.000 INCHES NOMINAL IN; Under Flange Height: 1.500 INCHES NOMINAL IN; Material: STEEL COMP 410 OVERALL. 6 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.