The Piston,valve, cataloged under National Stock Number 4820-01-194-4121, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 4 specifications, cited from the U.S. Government catalog. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-194-4121 |
| Item Name | Piston,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Outside Diameter | 0.938 INCHES NOMINAL IN |
| Material Document and Classification | QQ-S-763, COMP 303 FED SPEC SINGLE MATERIAL RESPONSE |
| Valve Design Control Activity | 97390 |
| Material | STEEL CORROSION RESISTING |
| 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 |
|---|---|
| X-77576 | D/9 Drawing number reference only U.S. Government activity |
| 74728 | 5/9 Secondary reference U.S. Government activity |
| X-77576 ITEM 1-V | 3/9 Design control — primary reference U.S. Government activity |
NSN 4820-01-194-4121 is a Piston,valve, classified under FSC 4820, Valves, Nonpowered. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 5120-01-722-5659. Verify interchangeability with system specifications before substitution.
Key specifications for 4820-01-194-4121: Outside Diameter: 0.938 INCHES NOMINAL IN; Material Document and Classification: QQ-S-763, COMP 303 FED SPEC SINGLE MATERIAL RESPONSE; Overall Length: 0.312 INCHES NOMINAL IN; Valve Design Control Activity: 97390. 4 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.