The Valve,safety Relief, cataloged under National Stock Number 4820-00-129-8674, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Avox Systems Inc Dba Avox Systems Inc. Government technical data includes 8 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4820-00-129-8674 |
| Primary Part Number | 156-165 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Avox Systems Inc Dba Avox Systems Inc |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Connection Style | PLAIN (HOSE) FIRST END |
| Nominal Inside Diameter Hose Accommodated | 0.250 INCHES FIRST END IN |
| Style Designator | STRAIGHT THRU |
| Disk Loading Method | SPRING |
| Material | PLASTIC BODY |
| Material | STEEL FLOW CONTROL DEVICE |
| 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 |
|---|---|
| 156-165 | Avox Systems Inc Dba Avox Systems Inc (USA) |
| Reference | Meaning |
|---|---|
| MILV81552 | 2/2 Government specification standardization U.S. Government activity |
NSN 4820-00-129-8674 is a Valve,safety Relief, manufactured by Avox Systems Inc Dba Avox Systems Inc, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-129-8674 has 1 manufacturer part number on file: 156-165 (Avox Systems Inc Dba Avox Systems Inc).
1 possible match (shared part number, not a government interchangeability claim): 5330-00-729-6536. Verify interchangeability with system specifications before substitution.
Key specifications for 156-165: Flow Control Device: DISK; Connection Style: PLAIN (HOSE) FIRST END; Nominal Inside Diameter Hose Accommodated: 0.250 INCHES FIRST END IN; Style Designator: STRAIGHT THRU. 8 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.