The Valve,check, cataloged under National Stock Number 4820-01-555-8561, 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 9 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-555-8561 |
| Primary Part Number | 803-1385721-62 |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Naval Sea Systems Command |
| Status | ACTIVE |
| Nominal Pipe Size Accommodated | 1.250 INCHES ALL ENDS IN |
| Connection Style | SOCKET (PIPE) ALL ENDS |
| Connection Type | UNTHREADED INTERNAL PIPE ALL ENDS |
| Style Designator | STRAIGHT THRU |
| Material Document and Classification | ASTM B61 ASSN STD SINGLE MATERIAL RESPONSE BODY |
| Valve Size | 1.250 INCHES IN |
| Face to Face Distance | 2.000 INCHES IN |
| Material | COPPER ALLOY 922 BODY |
| Valve Operation Method | AUTOMATIC |
| 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 |
|---|---|
| 803-1385721-62 PRIMARY | Naval Sea Systems Command (USA) |
| Reference | Meaning |
|---|---|
| 803-1385721 | D/9 Drawing number reference only U.S. Government activity |
| 803-1385721-62 | 3/2 Design control — primary reference U.S. Government activity |
NSN 4820-01-555-8561 is a Valve,check, manufactured by Naval Sea Systems Command, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-555-8561 has 1 manufacturer part number on file: 803-1385721-62 (Naval Sea Systems Command).
1 possible match (shared part number, not a government interchangeability claim): 4820-01-580-2002. Verify interchangeability with system specifications before substitution.
Key specifications for 803-1385721-62: Nominal Pipe Size Accommodated: 1.250 INCHES ALL ENDS IN; Connection Style: SOCKET (PIPE) ALL ENDS; Connection Type: UNTHREADED INTERNAL PIPE ALL ENDS; Style Designator: STRAIGHT THRU. 9 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.