The Valve,safety Relief, cataloged under National Stock Number 4820-00-203-8050, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Derbyshire Machine & Tool 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 | 4820-00-203-8050 |
| Primary Part Number | T898 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Derbyshire Machine & Tool Co |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Flange Shape | ROUND WITH HOLES FIRST END |
| Flange Face Design | PLAIN FIRST END |
| Bolt Circle Nominal Diameter | 6.562 INCHES FIRST END IN |
| Connection Type | FLANGE FIRST END |
| Style Designator | ANGLE |
| Bolt Hole Nominal Diameter | 0.562 INCHES FIRST END IN |
| Operating Pressure | 100.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Valve Size | 4.000 INCHES IN |
| Features Provided | PRESSURE TIGHT OUTLET SIDE |
| Maximum Operating Temp | 425.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Nominal Outside Diameter | 7.687 INCHES FIRST END IN |
| Disk Loading Method | SPRING |
| Bolt Hole Quantity | 8 FIRST END |
| Media for Which Designed | STEAM SINGLE RESPONSE |
| Material | COPPER ALLOY BODY |
| Opening Pressure Setting | 2.0 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 |
|---|---|
| T898 PRIMARY | Derbyshire Machine & Tool Co (USA) |
NSN 4820-00-203-8050 is a Valve,safety Relief, manufactured by Derbyshire Machine & Tool Co, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-203-8050 has 1 manufacturer part number on file: T898 (Derbyshire Machine & Tool Co).
Key specifications for T898: Flow Control Device: DISK; Flange Shape: ROUND WITH HOLES FIRST END; Flange Face Design: PLAIN FIRST END; Bolt Circle Nominal Diameter: 6.562 INCHES FIRST END IN. 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.