The Valve,safety Relief, cataloged under National Stock Number 4820-00-289-1840, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Watson Mcdaniel Co. Government technical data includes 19 specifications, cited from the U.S. Government catalog. The record lists 3 manufacturer part numbers 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 4820-00-289-1840 |
| Primary Part Number | TYPE R,3/4INCH |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Watson Mcdaniel Co |
| Status | ACTIVE |
| Flow Control Device | BALL |
| Nominal Pipe Size Accommodated | 0.750 INCHES FIRST END IN |
| Connection Style | PLAIN,OPTIONAL END(PIPE) ALL ENDS |
| Connection Type | THREADED INTERNAL PIPE ALL ENDS |
| Style Designator | ANGLE |
| Operating Pressure | 300.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Adjustable Pressure Range | +101.0 TO 300.0 POUNDS PER SQUARE INCH LBS |
| Features Provided | PRESSURE TIGHT OUTLET SIDE |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.750 INCHES ALL ENDS IN |
| Maximum Operating Temp | 400.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Media for Which Designed | WATER, FRESH SINGLE RESPONSE |
| Thread Quantity Per Inch | 14 FIRST END |
| Material | COPPER ALLOY BODY |
| Material | STEEL CORROSION RESISTING FLOW CONTROL DEVICE |
| Material | COPPER ALLOY SEAT |
| Thread Series Designator | NPT ALL ENDS |
| 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 |
|---|---|
| TYPE R,3/4INCH PRIMARY | Watson Mcdaniel Co (USA) |
| NY460-484-6PC11 | Amec Foster Wheeler North America Corp. Dba Foster Wheeler (USA) |
| S5101-880459ALT6PC11 | Naval Sea Systems Command (USA) |
| Reference | Meaning |
|---|---|
| S5101-880459ALT6PC11 | 5/9 Secondary reference U.S. Government activity |
NSN 4820-00-289-1840 is a Valve,safety Relief, manufactured by Watson Mcdaniel Co, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-289-1840 has 3 manufacturer part numbers on file: TYPE R,3/4INCH (Watson Mcdaniel Co), NY460-484-6PC11 (Amec Foster Wheeler North America Corp. Dba Foster Wheeler), S5101-880459ALT6PC11 (Naval Sea Systems Command).
Key specifications for TYPE R,3/4INCH: Flow Control Device: BALL; Nominal Pipe Size Accommodated: 0.750 INCHES FIRST END IN; Connection Style: PLAIN,OPTIONAL END(PIPE) ALL ENDS; Connection Type: THREADED INTERNAL PIPE ALL ENDS. 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.