The Valve,safety Relief, cataloged under National Stock Number 4820-01-338-7425, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 29 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-338-7425 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Flange Shape | ROUND WITH HOLES ALL ENDS |
| Flange Face Design | RAISED STRAIGHT ALL ENDS |
| Bolt Circle Nominal Diameter | 4.500 INCHES SECOND END IN |
| Bolt Circle Nominal Diameter | 5.500 INCHES FIRST END IN |
| Connection Type | FLANGE ALL ENDS |
| Style Designator | ANGLE FLANGED ENDS |
| Bolt Hole Nominal Diameter | 0.750 INCHES FIRST END IN |
| Bolt Hole Nominal Diameter | 0.875 INCHES SECOND END IN |
| Valve Size | 1.500 INCHES IN |
| Adjustable Pressure Range | +1055.0 TO 1160.0 POUNDS PER SQUARE INCH LBS |
| Bonnet Type | INSIDE SPRING |
| Maximum Operating Temp | 400.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Nominal Outside Diameter | 7.000 INCHES FIRST END IN |
| Nominal Outside Diameter | 6.125 INCHES SECOND END IN |
| Disk Loading Method | SPRING |
| Bolt Hole Quantity | 4 ALL ENDS |
| Bonnet Attachment Method | INTEGRAL |
| Media for Which Designed | STEAM SINGLE RESPONSE |
| Material | STEEL BODY |
| Material | STEEL CORROSION RESISTING FLOW CONTROL DEVICE |
| Material | STEEL CORROSION RESISTING SEAT |
| Material | STEEL CORROSION RESISTING STEM |
| Raised Face Nominal Diameter | 2.750 INCHES SECOND END IN |
| Raised Face Nominal Diameter | 3.562 INCHES FIRST END IN |
| Valve Operation Method | AUTOMATIC |
| Raised Face Nominal Height | 0.062 INCHES FIRST END IN |
| Raised Face Nominal Height | 0.250 INCHES SECOND END IN |
| Nominal Thickness | 0.875 INCHES ALL ENDS IN |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Reference | Meaning |
|---|---|
| R10AH9K534-CH4 | 3/9 Design control — primary reference Hunt Valve Company Inc Dba Union Flonetics |
| R10AH9K534-CH4 | C/1 Advisory reference — outside the item-of-supply concept Hunt Valve Company, Inc. |
NSN 4820-01-338-7425 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-01-338-7425: Flow Control Device: DISK; Flange Shape: ROUND WITH HOLES ALL ENDS; Flange Face Design: RAISED STRAIGHT ALL ENDS; Bolt Circle Nominal Diameter: 4.500 INCHES SECOND END IN. 29 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.