The Seat,valve, cataloged under National Stock Number 4820-01-121-0495, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 8 specifications, cited from the U.S. Government catalog. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-121-0495 |
| Item Name | Seat,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flange Seat to Disk End Height | 0.188 INCHES NOMINAL IN |
| Flange Diameter | 2.500 INCHES NOMINAL IN |
| Body Outside Diameter | 2.250 INCHES NOMINAL IN |
| Style Designator | PLAIN FLANGED |
| Body Inside Diameter | 1.875 INCHES NOMINAL IN |
| Under Flange Height | 0.375 INCHES NOMINAL IN |
| Material | NICKEL ALLOY 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 |
|---|---|
| NB-0102-H-0200 PART 18 | 3/9 Design control — primary reference Pima Valve, Llc |
| NB-0102-HSC-0000-SL | D/9 Drawing number reference only Pima Valve, Llc |
| NB-0102-H-0200 PART 18 | C/1 Advisory reference — outside the item-of-supply concept Hunt Valve Company, Inc. |
NSN 4820-01-121-0495 is a Seat,valve, classified under FSC 4820, Valves, Nonpowered. Status: active.
2 possible matches (shared part number, not a government interchangeability claim): 4820-01-164-7062, 4820-01-220-0835. Verify interchangeability with system specifications before substitution.
Key specifications for 4820-01-121-0495: Flange Seat to Disk End Height: 0.188 INCHES NOMINAL IN; Flange Diameter: 2.500 INCHES NOMINAL IN; Body Outside Diameter: 2.250 INCHES NOMINAL IN; Style Designator: PLAIN FLANGED. 8 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.