The Valve,safety Relief, cataloged under National Stock Number 4820-01-111-3989, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Mueller Brass Co.. Government technical data includes 18 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. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-111-3989 |
| Primary Part Number | A15504-400 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Mueller Brass Co. |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Connection Style | FLARED (TUBE) FIRST END |
| Connection Style | PLAIN (PIPE) SECOND END |
| Connection Type | THREADED EXTERNAL PIPE SECOND END |
| Connection Type | THREADED EXTERNAL TUBE FIRST END |
| Style Designator | STRAIGHT THRU NOTE: TO BE USED FOR VALVE BODIES OF SEPARABLE SECTIONS. |
| Thread Direction | RIGHT-HAND SECOND END |
| Thread Direction | RIGHT-HAND FIRST END |
| Nominal Thread Size | 0.625 INCHES FIRST END IN |
| Nominal Thread Size | 0.500 INCHES SECOND END IN |
| Seat Angle | 37.0 DEGREES FIRST END |
| Thread Class | 2A FIRST END A |
| Material | COPPER ALLOY BODY |
| Material | RUBBER SYNTHETIC FLOW CONTROL DEVICE |
| Thread Series Designator | NPT SECOND END |
| Thread Series Designator | UNF FIRST END |
| Opening Pressure Setting | 400.0 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 |
|---|---|
| A15504-400 PRIMARY | Mueller Brass Co. (USA) |
NSN 4820-01-111-3989 is a Valve,safety Relief, manufactured by Mueller Brass Co., classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-111-3989 has 1 manufacturer part number on file: A15504-400 (Mueller Brass Co.).
Key specifications for A15504-400: Flow Control Device: DISK; Connection Style: FLARED (TUBE) FIRST END; Connection Style: PLAIN (PIPE) SECOND END; Connection Type: THREADED EXTERNAL PIPE SECOND END. 18 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.