The Stem,fluid Valve, cataloged under National Stock Number 4820-01-121-9581, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Naval Sea Systems Command. Government technical data includes 3 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. 9 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 6 items share a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-121-9581 |
| Primary Part Number | 516-4775903 ITEM 11 |
| Item Name | Stem,fluid Valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Naval Sea Systems Command |
| Status | ACTIVE |
| Largest Outside Diameter | 0.623 INCHES NOMINAL IN |
| Valve Model Number for Which Designed | 516-4788433 |
| Material | ALUMINUM ALLOY |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| 516-4775903 ITEM 11 | Naval Sea Systems Command (USA) |
| Reference | Meaning |
|---|---|
| 518-4775893 ITEM 6 | 5/2 Secondary reference U.S. Government activity |
| 516-4788433 ITEM 5 | 5/2 Secondary reference U.S. Government activity |
| 518-4775891 ITEM 20 | 5/2 Secondary reference U.S. Government activity |
| 87791-4602 ITEM 5 | 3/2 Design control — primary reference U.S. Government activity |
| 87791-4602 | D/9 Drawing number reference only U.S. Government activity |
| 4788433-0005 | 5/2 Secondary reference U.S. Government activity |
| 516-4788433 | D/9 Drawing number reference only U.S. Government activity |
| 516-4775903 ITEM 11 | 5/2 Secondary reference U.S. Government activity |
| 516-4775900 ITEM 7 | 5/2 Secondary reference U.S. Government activity |
NSN 4820-01-121-9581 is a Stem,fluid Valve, manufactured by Naval Sea Systems Command, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-121-9581 has 1 manufacturer part number on file: 516-4775903 ITEM 11 (Naval Sea Systems Command).
6 possible matches (shared part number, not a government interchangeability claim): 4820-01-123-3121, 4820-01-129-7781, 4730-01-132-9128. Verify interchangeability with system specifications before substitution.
Key specifications for 516-4775903 ITEM 11: Largest Outside Diameter: 0.623 INCHES NOMINAL IN; Valve Model Number for Which Designed: 516-4788433; Overall Length: 3.000 INCHES NOMINAL IN; End Item Identification: NAVY MANIFOLD LEAD PUMP AND ACC DISCHARGE DET MODEL NO. 516-4788433. 3 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.