The Valve,upper Exhaust, cataloged under National Stock Number 4820-01-021-1787, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 1 specification, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-021-1787 |
| Item Name | Valve,upper Exhaust |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| General Characteristics Item Description | SPRING STEEL; 2.995 IN. LG; 0.635 IN. WIDE; 0.019 IN. THK; 0.285 IN. HOLE DIA IN |
| 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 |
|---|---|
| 41-2153 | 3/9 Design control — primary reference Sargent-Welch Scientific Co |
NSN 4820-01-021-1787 is a Valve,upper Exhaust, classified under FSC 4820, Valves, Nonpowered. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 5985-01-389-3573. Verify interchangeability with system specifications before substitution.
Key specifications for 4820-01-021-1787: General Characteristics Item Description: SPRING STEEL; 2.995 IN. LG; 0.635 IN. WIDE; 0.019 IN. THK; 0.285 IN. HOLE DIA IN. 1 specification is 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.