The Valve,safety Relief, cataloged under National Stock Number 4820-00-166-0263, 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28 specifications, cited from the U.S. Government catalog. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-00-166-0263 |
| 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 Shape | ROUND WITH HOLES SECOND END |
| Renewable Seat Ring Type | THREADED |
| Flange Face Design | PLAIN FIRST END |
| Flange Face Design | PLAIN SECOND END |
| Bolt Circle Nominal Diameter | 5.875 INCHES SECOND END IN |
| Bolt Circle Nominal Diameter | 7.125 INCHES FIRST END IN |
| Connection Type | FLANGE SECOND END |
| Connection Type | FLANGE FIRST END |
| Style Designator | ANGLE FLANGED ENDS |
| Bolt Hole Nominal Diameter | 0.812 INCHES SECOND END IN |
| Bolt Hole Nominal Diameter | 0.812 INCHES FIRST END IN |
| Valve Size | 2.500 INCHES IN |
| Features Provided | PRESSURE TIGHT OUTLET SIDE |
| Bonnet Type | EXPOSED SPRING |
| Nominal Outside Diameter | 8.688 INCHES FIRST END IN |
| Nominal Outside Diameter | 7.500 INCHES SECOND END IN |
| Disk Loading Method | SPRING |
| Bolt Hole Quantity | 8 SECOND END |
| Bolt Hole Quantity | 9 FIRST END |
| Bonnet Attachment Method | BOLTED |
| Opening Pressure Setting | 700.0 POUNDS PER SQUARE INCH LBS |
| Valve Discharge Flow Rate | 31000.0 POUNDS PER HOUR LBS |
| Valve Operation Method | AUTOMATIC OR MANUAL |
| Nominal Thickness | 1.125 INCHES SECOND END IN |
| Nominal Thickness | 0.875 INCHES FIRST END IN |
| Reference Number Differentiating Characteristics | AS DIFFERENTIATED BY THE VALVE DISCHARGE FLOW RATE REQUIREMENT |
| 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 |
|---|---|
| A34150CAP31000 | 5/1 Secondary reference Emerson Automation Solutions Final Control Us Lp Div Navy Product Team |
| HNB5 | 5/1 Secondary reference Emerson Automation Solutions Final Control Us Lp Div Navy Product Team |
| A34150 | 3/1 Design control — primary reference Emerson Automation Solutions Final Control Us Lp Div Navy Product Team |
NSN 4820-00-166-0263 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
2 possible matches (shared part number, not a government interchangeability claim): 4820-00-288-6926, 4820-01-300-5940. Verify interchangeability with system specifications before substitution.
Key specifications for 4820-00-166-0263: Flow Control Device: DISK; Flange Shape: ROUND WITH HOLES FIRST END; Flange Shape: ROUND WITH HOLES SECOND END; Renewable Seat Ring Type: THREADED. 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.