The Stem,fluid Valve, cataloged under National Stock Number 4820-01-162-6551, 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 5 specifications, cited from the U.S. Government catalog. The record lists 2 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-162-6551 |
| Primary Part Number | 506-5588397 PART 20 |
| Item Name | Stem,fluid Valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Naval Sea Systems Command |
| Status | ACTIVE |
| Valve Type for Which Designed | LIFT-CHECK |
| Stem Actuating End Type | THREADED EXTERNALLY |
| Material Document and Classification | QQ-N-286, CLASS HF OR AH FED SPEC SINGLE MATERIAL RESPONSE |
| Valve Size for Which Designed | 4.000 INCHES IN |
| Material | NICKEL 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 |
|---|---|
| 2401-443 PART 20 | Huntington Ingalls Inc Div Newport News Shipbuilding (USA) |
| 506-5588397 PART 20 PRIMARY | Naval Sea Systems Command (USA) |
| Reference | Meaning |
|---|---|
| 506-5588397 | D/9 Drawing number reference only Naval Sea Systems Command |
| 2401-443 | D/9 Drawing number reference only Huntington Ingalls Inc Div Newport News Shipbuilding |
NSN 4820-01-162-6551 is a Stem,fluid Valve, manufactured by Naval Sea Systems Command, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-162-6551 has 2 manufacturer part numbers on file: 2401-443 PART 20 (Huntington Ingalls Inc Div Newport News Shipbuilding), 506-5588397 PART 20 (Naval Sea Systems Command).
1 possible match (shared part number, not a government interchangeability claim): 4820-01-175-6510. Verify interchangeability with system specifications before substitution.
Key specifications for 506-5588397 PART 20: Valve Type for Which Designed: LIFT-CHECK; Stem Actuating End Type: THREADED EXTERNALLY; Material Document and Classification: QQ-N-286, CLASS HF OR AH FED SPEC SINGLE MATERIAL RESPONSE; Valve Size for Which Designed: 4.000 INCHES IN. 5 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.