The Valve,safety Relief, cataloged under National Stock Number 4820-01-124-9979, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Honeywell International Inc. Div Aerospace - Torrance. Government technical data includes 21 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-124-9979 |
| Primary Part Number | 559B-1M-8 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Honeywell International Inc. Div Aerospace - Torrance |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Connection Style | PLAIN (PIPE) ALL ENDS |
| Connection Type | THREADED EXTERNAL PIPE ALL ENDS |
| Style Designator | STRAIGHT THRU |
| Operating Pressure | 200.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.125 INCHES ALL ENDS IN |
| Maximum Operating Temp | 250.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Surface Treatment | CHROMIUM LOCATION NOT OTHERWISE SPECIFIED |
| Media for Which Designed | FUEL/OIL, HYDROCARBON SECOND RESPONSE |
| Media for Which Designed | HYDROGEN FOURTH RESPONSE |
| Media for Which Designed | AIR FIRST RESPONSE |
| Media for Which Designed | REFRIGERANT 12 THIRD RESPONSE |
| Media for Which Designed | GAS, INERT FIFTH RESPONSE |
| Material | COPPER ALLOY BODY |
| Material | COPPER ALLOY AND RUBBER BUTADIENE-ACRYLONITRILE CLASS NBR FLOW CONTROL DEVICE |
| Material | COPPER ALLOY SEAT |
| Thread Series Designator | NPT ALL ENDS |
| Opening Pressure Setting | 8.0 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 |
| Part Number | Manufacturer |
|---|---|
| 559B-1M-8 | Honeywell International Inc. Div Aerospace - Torrance (USA) |
| Reference | Meaning |
|---|---|
| 559B-1M-8 | 3/2 Design control — primary reference U.S. Government activity |
NSN 4820-01-124-9979 is a Valve,safety Relief, manufactured by Honeywell International Inc. Div Aerospace - Torrance, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-124-9979 has 1 manufacturer part number on file: 559B-1M-8 (Honeywell International Inc. Div Aerospace - Torrance).
Key specifications for 559B-1M-8: Flow Control Device: POPPET; Connection Style: PLAIN (PIPE) ALL ENDS; Connection Type: THREADED EXTERNAL PIPE ALL ENDS; Style Designator: STRAIGHT THRU. 21 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.