The Inner Valve Unit, cataloged under National Stock Number 4820-01-197-9983, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 2 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-197-9983 |
| Item Name | Inner Valve Unit |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Criticality Code Justification | ZZZY |
| Reference Number Differentiating Characteristics | CLEANING, PACKAGING, AND MARKING IAW THE LATEST REVISION OF MIL-STD-1330 |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | S |
| Reference | Meaning |
|---|---|
| 19252 ITEM 11 | 5/1 Secondary reference Fluid Mechanics Valve Company |
| 1-170-04A7 | 3/1 Design control — primary reference Fluid Mechanics Valve Company |
NSN 4820-01-197-9983 is a Inner Valve Unit, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-01-197-9983: Criticality Code Justification: ZZZY; End Item Identification: VARIOUS SUBMARINE PUMPS; Reference Number Differentiating Characteristics: CLEANING, PACKAGING, AND MARKING IAW THE LATEST REVISION OF MIL-STD-1330. 2 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.