The Valve,safety Relief, cataloged under National Stock Number 4820-01-499-4910, 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 13 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 4820-01-499-4910 |
| Primary Part Number | AH15509 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Mueller Brass Co. |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Connection Style | PLAIN (PIPE) ALL ENDS |
| Connection Type | THREADED EXTERNAL PIPE ALL ENDS |
| Style Designator | ANGLE |
| Bonnet Type | INSIDE SPRING |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.250 INCHES ALL ENDS IN |
| Disk Loading Method | SPRING |
| Bonnet Attachment Method | UNION |
| Material | COPPER ALLOY BODY |
| Thread Series Designator | NPT ALL ENDS |
| 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 |
|---|---|
| AH15509 PRIMARY | Mueller Brass Co. (USA) |
| Reference | Meaning |
|---|---|
| A-15509-AH-400PSI-BSP 1/4 | 5/9 Secondary reference Mueller Brass Co. |
NSN 4820-01-499-4910 is a Valve,safety Relief, manufactured by Mueller Brass Co., classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-499-4910 has 1 manufacturer part number on file: AH15509 (Mueller Brass Co.).
Key specifications for AH15509: Flow Control Device: DISK; Connection Style: PLAIN (PIPE) ALL ENDS; Connection Type: THREADED EXTERNAL PIPE ALL ENDS; Style Designator: ANGLE. 13 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.