The Valve,safety Relief, cataloged under National Stock Number 4820-01-092-6121, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Pneu-Hydro Products. Government technical data includes 19 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through both NSN and commercial part number lookups. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-092-6121 |
| Primary Part Number | 401F4Q3 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Pneu-Hydro Products |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Connection Style | PLAIN,OPTIONAL END(PIPE) ALL ENDS |
| Connection Type | THREADED INTERNAL PIPE ALL ENDS |
| Style Designator | STRAIGHT THRU NOTE: TO BE USED FOR VALVE BODIES OF SEPARABLE SECTIONS. |
| Material Document and Classification | QQ-S-763,CLASS 303 FED SPEC SINGLE MATERIAL RESPONSE BODY |
| Operating Pressure | 650.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Features Provided | PRESSURE TIGHT OUTLET SIDE |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.250 INCHES ALL ENDS IN |
| Maximum Operating Temp | 225.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Surface Treatment | PASSIVATE LOCATION NOT OTHERWISE SPECIFIED |
| Media for Which Designed | AIR SINGLE RESPONSE |
| Material | STEEL COMP 303 FLOW CONTROL DEVICE |
| Material | STEEL COMP 303 BODY |
| Material | RUBBER SYNTHETIC SEAT |
| Thread Series Designator | NPT ALL ENDS |
| Opening Pressure Setting | 630.0 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 |
|---|---|
| 401F4Q3 PRIMARY | Pneu-Hydro Products (USA) |
| Reference | Meaning |
|---|---|
| 631AS104 | D/9 Drawing number reference only Naval Air Systems Command Managed Original Design Activity Not Material/parts Supplier |
| 631AS104-1 | 7/2 Vendor item drawing reference Naval Air Systems Command Managed Original Design Activity Not Material/parts Supplier |
| S665-6-1/4SS2 | 5/9 Secondary reference U.S. Government activity |
| 401F4S3 | 5/9 Secondary reference Pneu-Hydro Products |
| 5159T-2PP-630 | 5/9 Secondary reference U.S. Government activity |
NSN 4820-01-092-6121 is a Valve,safety Relief, manufactured by Pneu-Hydro Products, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-092-6121 has 1 manufacturer part number on file: 401F4Q3 (Pneu-Hydro Products).
Key specifications for 401F4Q3: Flow Control Device: POPPET; Connection Style: PLAIN,OPTIONAL END(PIPE) ALL ENDS; Connection Type: THREADED INTERNAL PIPE ALL ENDS; Style Designator: STRAIGHT THRU NOTE: TO BE USED FOR VALVE BODIES OF SEPARABLE SECTIONS.. 19 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.