The Valve,safety Relief, cataloged under National Stock Number 4820-01-331-8683, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 28 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-331-8683 |
| 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 | 3.875 INCHES SECOND END IN |
| Bolt Circle Nominal Diameter | 4.750 INCHES FIRST END IN |
| Connection Type | FLANGE ALL ENDS |
| Style Designator | ANGLE FLANGED ENDS |
| Bolt Hole Nominal Diameter | 0.625 INCHES SECOND END IN |
| Bolt Hole Nominal Diameter | 0.750 INCHES FIRST END IN |
| Operating Pressure | 185.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SECOND RESPONSE LBS |
| Operating Pressure | 285.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM FIRST RESPONSE LBS |
| Valve Size | 1.500 INCHES IN |
| Adjustable Pressure Range | +15.0 TO 20.0 POUNDS PER SQUARE INCH LBS |
| Maximum Operating Temp | 450.0 FAHRENHEIT SECOND RESPONSE DEGF |
| Maximum Operating Temp | 100.0 FAHRENHEIT FIRST RESPONSE DEGF |
| Second Connection Face to Centerline Distance | 4.875 INCHES IN |
| Nominal Outside Diameter | 5.000 INCHES SECOND END IN |
| Nominal Outside Diameter | 6.000 INCHES FIRST END IN |
| Bolt Hole Quantity | 4 ALL ENDS |
| First Connection Face to Centerline Distance | 4.750 INCHES IN |
| Material | STEEL BODY |
| Material | STEEL COMP 316 FLOW CONTROL DEVICE |
| Raised Face Nominal Diameter | 2.750 INCHES SECOND END IN |
| Raised Face Nominal Diameter | 3.250 INCHES FIRST END IN |
| Valve Operation Method | AUTOMATIC |
| Raised Face Nominal Height | 0.062 INCHES ALL ENDS IN |
| Nominal Thickness | 0.688 INCHES SECOND END IN |
| Nominal Thickness | 0.750 INCHES FIRST END 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 |
|---|---|
| 1905-30FC-1 S/N TH72190-193 | 3/9 Design control — primary reference Dresser, Inc. Dba Dresser Equipment Group Div Industrial Valve Operations, Dresse |
NSN 4820-01-331-8683 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-01-331-8683: Flow Control Device: DISK; Flange Shape: ROUND WITH HOLES ALL ENDS; Flange Face Design: RAISED STRAIGHT ALL ENDS; Bolt Circle Nominal Diameter: 3.875 INCHES SECOND END IN. 28 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.