The Valve,safety Relief, cataloged under National Stock Number 4820-00-844-6554, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Ashcroft Inc Dba Heise. Government technical data includes 17 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 | 4820-00-844-6554 |
| Primary Part Number | 1471 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Ashcroft Inc Dba Heise |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Connection Style | PLAIN,OPTIONAL END(PIPE) SECOND END |
| Connection Style | PLAIN (PIPE) FIRST END |
| Connection Type | THREADED INTERNAL PIPE SECOND END |
| Connection Type | THREADED EXTERNAL PIPE FIRST END |
| Style Designator | ANGLE |
| Operating Pressure | 300.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 1.000 INCHES SECOND END IN |
| Nominal Thread Size | 0.500 INCHES FIRST END IN |
| Maximum Operating Temp | 450.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Media for Which Designed | WATER-OIL-GAS SECOND RESPONSE |
| Media for Which Designed | STEAM FIRST RESPONSE |
| Material | COPPER ALLOY OVERALL |
| Thread Series Designator | NPT ALL ENDS |
| Opening Pressure Setting | 35.0 POUNDS PER SQUARE INCH LBS |
| Valve Operation Method | AUTOMATIC OR MANUAL |
| 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 |
|---|---|
| 1471 PRIMARY | Ashcroft Inc Dba Heise (USA) |
NSN 4820-00-844-6554 is a Valve,safety Relief, manufactured by Ashcroft Inc Dba Heise, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-844-6554 has 1 manufacturer part number on file: 1471 (Ashcroft Inc Dba Heise).
Key specifications for 1471: Flow Control Device: DISK; Connection Style: PLAIN,OPTIONAL END(PIPE) SECOND END; Connection Style: PLAIN (PIPE) FIRST END; Connection Type: THREADED INTERNAL PIPE SECOND END. 17 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.