The Valve,safety Relief, cataloged under National Stock Number 4820-01-200-8556, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 25 specifications, cited from the U.S. Government catalog. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-200-8556 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | DISKDISK |
| Flange Shape | ROUND WITH HOLES FIRST END |
| Flange Shape | ROUND WITH HOLES SECOND END |
| Flange Face Design | RAISED STRAIGHT FIRST END |
| Bolt Circle Nominal Diameter | 4.750 INCHES FIRST END IN |
| Bolt Circle Nominal Diameter | 3.500 INCHES SECOND END IN |
| Connection Type | FLANGE FIRST END |
| Bolt Hole Nominal Diameter | 0.750 INCHES SECOND END IN |
| Bolt Hole Nominal Diameter | 0.750 INCHES FIRST END IN |
| Valve Size | 1.000 INCHES IN |
| Bonnet Type | INSIDE SPRINGINSIDE SPRING |
| Second Connection Face to Centerline Distance | 4.125 INCHES IN |
| Nominal Outside Diameter | 6.000 INCHES FIRST END IN |
| Nominal Outside Diameter | 4.875 INCHES SECOND END IN |
| Disk Loading Method | SPRINGSPRING |
| Bonnet Attachment Method | BOLTEDBOLTED |
| First Connection Face to Centerline Distance | 4.500 INCHES IN |
| Material | STEEL CORROSION RESISTING FLOW CONTROL DEVICE |
| Material | STEEL CORROSION RESISTING BODY |
| Raised Face Nominal Diameter | 3.625 INCHES FIRST END IN |
| Opening Pressure Setting | 448.0 POUNDS PER SQUARE INCH LBS |
| Valve Operation Method | AUTOMATICAUTOMATIC |
| Raised Face Nominal Height | 0.062 INCHES FIRST END IN |
| Nominal Thickness | 0.688 INCHES FIRST END IN |
| Nominal Thickness | 0.688 INCHES SECOND 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 |
|---|---|
| 1900D | D/9 Drawing number reference only Dresser, Inc. Dba Dresser Equipment Group Div Industrial Valve Operations, Dresse |
| 1900D-1912DC 44 | C/1 Advisory reference — outside the item-of-supply concept Dresser, Inc. Dba Dresser Equipment Group Div Industrial Valve Operations, Dresse |
| 1912-00D-2-CC-MS-31-RF-LA-H | 5/9 Secondary reference Dresser, Inc. Dba Dresser Equipment Group Div Industrial Valve Operations, Dresse |
| 1900D-1912DC 448PSI BBT | 5/9 Secondary reference Dresser, Inc. Dba Dresser Equipment Group Div Industrial Valve Operations, Dresse |
| 1912DC-00-2MS-31-RF-LA | 3/9 Design control — primary reference Dresser, Inc. Dba Dresser Equipment Group Div Industrial Valve Operations, Dresse |
NSN 4820-01-200-8556 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-01-200-8556: Flow Control Device: DISKDISK; Flange Shape: ROUND WITH HOLES FIRST END; Flange Shape: ROUND WITH HOLES SECOND END; Flange Face Design: RAISED STRAIGHT FIRST END. 25 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.