The Valve,safety Relief, cataloged under National Stock Number 4820-01-187-6823, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Anderson Greenwood Lp Dba Anderson Greenwood Crosby. Government technical data includes 12 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 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 | 4820-01-187-6823 |
| Primary Part Number | 171-S |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Anderson Greenwood Lp Dba Anderson Greenwood Crosby |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Connection Style | PLAIN,OPTIONAL END(PIPE) ALL ENDS |
| Connection Type | THREADED INTERNAL PIPE ALL ENDS |
| Style Designator | ANGLE |
| Bonnet Type | INSIDE SCREW |
| Thread Direction | RIGHT-HAND FIRST END |
| Nominal Thread Size | 0.750 INCHES FIRST END IN |
| Bonnet Attachment Method | THREADED |
| Material | STEEL COMP 316 BODY |
| Thread Series Designator | NPT FIRST END |
| Opening Pressure Setting | 50.0 POUNDS PER SQUARE INCH LBS |
| 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 |
NSN 4820-01-187-6823 is a Valve,safety Relief, manufactured by Anderson Greenwood Lp Dba Anderson Greenwood Crosby, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-187-6823 has 2 manufacturer part numbers on file: 171-S (Anderson Greenwood Lp Dba Anderson Greenwood Crosby), 5205345 (Naval Sea Systems Command).
2 possible matches (shared part number, not a government interchangeability claim): 3040-01-330-5031, 7025-01-544-2775. Verify interchangeability with system specifications before substitution.
Key specifications for 171-S: Flow Control Device: DISK; Connection Style: PLAIN,OPTIONAL END(PIPE) ALL ENDS; Connection Type: THREADED INTERNAL PIPE ALL ENDS; Style Designator: ANGLE. 12 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.