The Valve,safety Relief, cataloged under National Stock Number 4820-00-727-8028, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Navair and Navsea Managed Original Design Activity Dwg Not Material/parts Supplier. Government technical data includes 28 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-00-727-8028 |
| Primary Part Number | 1390424 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Navair and Navsea Managed Original Design Activity Dwg Not Material/parts Supplier |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Nominal Pipe Size Accommodated | 0.250 INCHES FIRST END IN |
| Nominal Pipe Size Accommodated | 0.250 INCHES SECOND END IN |
| Connection Style | PLAIN,OPTIONAL END(PIPE) FIRST END |
| Connection Style | PLAIN (PIPE) SECOND END |
| Connection Type | THREADED INTERNAL PIPE FIRST END |
| Connection Type | THREADED EXTERNAL PIPE SECOND END |
| Material Document and Classification | FED STD 66 FED STD 1ST MATERIAL RESPONSE FLOW CONTROL DEVICE |
| Operating Pressure | 50.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Features Provided | PRESSURE TIGHT OUTLET SIDE |
| Bonnet Type | INSIDE SCREW |
| Thread Direction | RIGHT-HAND SECOND END |
| Thread Direction | RIGHT-HAND FIRST END |
| Nominal Thread Size | 0.250 INCHES FIRST END IN |
| Nominal Thread Size | 0.250 INCHES SECOND END IN |
| Maximum Operating Temp | 180.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Bonnet Attachment Method | INTEGRAL |
| Media for Which Designed | GAS, NATURAL SECOND RESPONSE |
| Media for Which Designed | AIR FIRST RESPONSE |
| Thread Quantity Per Inch | 18 SECOND END |
| Material | COPPER ALLOY BODY |
| Material | COPPER ALLOY SEAT |
| Material | STEEL COMP 303 AND RUBBER BUTADIENE-ACRYLONITRILE CLASS NBR FLOW CONTROL DEVICE |
| Thread Series Designator | NPT SECOND END |
| Thread Series Designator | NPT FIRST END |
| Opening Pressure Setting | 25.0 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 |
|---|---|
| 1390424 PRIMARY | Navair and Navsea Managed Original Design Activity Dwg Not Material/parts Supplier (USA) |
| Reference | Meaning |
|---|---|
| 684-2-1/4B2 | 5/9 Secondary reference U.S. Government activity |
| 684-2-1-1/4B25 | 5/9 Secondary reference U.S. Government activity |
| 684-2-1/4B25 | 5/9 Secondary reference U.S. Government activity |
NSN 4820-00-727-8028 is a Valve,safety Relief, manufactured by Navair and Navsea Managed Original Design Activity Dwg Not Material/parts Supplier, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-727-8028 has 1 manufacturer part number on file: 1390424 (Navair and Navsea Managed Original Design Activity Dwg Not Material/parts Supplier).
Key specifications for 1390424: Flow Control Device: POPPET; Nominal Pipe Size Accommodated: 0.250 INCHES FIRST END IN; Nominal Pipe Size Accommodated: 0.250 INCHES SECOND END IN; Connection Style: PLAIN,OPTIONAL END(PIPE) FIRST END. 28 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.