The Seat,valve, cataloged under National Stock Number 4820-00-587-2181, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 7 specifications, cited from the U.S. Government catalog. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government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 | 4820-00-587-2181 |
| Item Name | Seat,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flange Diameter | 0.247 INCHES MINIMUM AND 0.248 INCHES MAXIMUM IN |
| Body Outside Diameter | 0.137 INCHES MINIMUM AND 0.190 INCHES MAXIMUM IN |
| Hardness Rating | 58.0 ROCKWELL C MINIMUM AND 62.0 ROCKWELL C MAXIMUM OVERALL |
| Body Inside Diameter | 0.031 INCHES MINIMUM AND 0.065 INCHES MAXIMUM IN |
| Surface Treatment | PASSIVATE OVERALL |
| Material | STEEL COMP 440C OVERALL |
| 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 |
|---|---|
| 14267 | 5/9 Secondary reference E-Systems Inc Montek Div Fluid Controls Opns |
| 14267 | 3/9 Design control — primary reference Mid-America Aerotech, Llc |
| 14267 | 5/9 Secondary reference Moog Inc Div Moog Inc., Space and Defense - Salt Lake City |
| 14267 | 5/9 Secondary reference U.S. Government activity |
NSN 4820-00-587-2181 is a Seat,valve, classified under FSC 4820, Valves, Nonpowered. Status: active.
2 possible matches (shared part number, not a government interchangeability claim): 1650-00-736-4493, 9905-01-145-9270. Verify interchangeability with system specifications before substitution.
Key specifications for 4820-00-587-2181: Flange Diameter: 0.247 INCHES MINIMUM AND 0.248 INCHES MAXIMUM IN; Overall Height: 0.349 INCHES MINIMUM AND 0.353 INCHES MAXIMUM IN; Body Outside Diameter: 0.137 INCHES MINIMUM AND 0.190 INCHES MAXIMUM IN; Hardness Rating: 58.0 ROCKWELL C MINIMUM AND 62.0 ROCKWELL C MAXIMUM OVERALL. 7 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.