The Valve,safety Relief, cataloged under National Stock Number 4820-00-203-7912, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 27 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 4820-00-203-7912 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Flange Shape | ROUND WITH HOLES FIRST END |
| Flange Face Design | PLAIN FIRST END |
| Bolt Circle Nominal Diameter | 8.875 INCHES FIRST END IN |
| Connection Type | FLANGE SECOND END |
| Connection Type | FLANGE FIRST END |
| Style Designator | ANGLE FLANGED ENDS |
| Bolt Hole Nominal Diameter | 0.688 INCHES FIRST END IN |
| Operating Pressure | 100.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Features Provided | PRESSURE TIGHT OUTLET SIDE |
| Bonnet Type | INSIDE SPRING |
| Maximum Operating Temp | 425.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Second Connection Face to Centerline Distance | 8.000 INCHES IN |
| Nominal Outside Diameter | 10.125 INCHES FIRST END IN |
| Disk Loading Method | SPRING |
| Bolt Hole Quantity | 12 FIRST END |
| Bonnet Attachment Method | BOLTED |
| Media for Which Designed | STEAM SINGLE RESPONSE |
| First Connection Face to Centerline Distance | 8.000 INCHES IN |
| Material | COPPER ALLOY BODY |
| Material | COPPER ALLOY FLOW CONTROL DEVICE |
| Material | COPPER ALLOY STEM |
| Material | COPPER ALLOY SEAT |
| Opening Pressure Setting | 2.0 POUNDS PER SQUARE INCH LBS |
| Valve Operation Method | AUTOMATIC OR MANUAL |
| Nominal Thickness | 0.562 INCHES FIRST END IN |
| Reference Number Differentiating Characteristics | ELR NO. |
| 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 |
|---|---|
| 5S1166ALT9AND5S1179ALT8AND5S128- | 3/1 Design control — primary reference U.S. Government activity |
NSN 4820-00-203-7912 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-00-203-7912: Flow Control Device: DISK; Flange Shape: ROUND WITH HOLES FIRST END; Flange Face Design: PLAIN FIRST END; Bolt Circle Nominal Diameter: 8.875 INCHES FIRST END IN. 27 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.