The Valve,safety Relief, cataloged under National Stock Number 4820-00-289-4384, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Westinghouse Electric Corp. Government technical data includes 13 specifications, cited from the U.S. Government catalog. The record lists 4 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 15 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 3 items share a part number with this NSN in the catalog (possible match — not a government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 | 4820-00-289-4384 |
| Primary Part Number | 22773PC1T021 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Westinghouse Electric Corp |
| Status | ACTIVE |
| Flange Shape | ROUND WITH HOLES FIRST END |
| Flange Face Design | PLAIN FIRST END |
| Bolt Circle Nominal Diameter | 4.438 INCHES FIRST END IN |
| Connection Type | FLANGE FIRST END |
| Style Designator | ANGLE |
| Bolt Hole Nominal Diameter | 0.562 INCHES FIRST END IN |
| Operating Pressure | 150.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Adjustable Pressure Range | +0.0 TO 30.0 POUNDS PER SQUARE INCH LBS |
| Nominal Outside Diameter | 5.562 INCHES FIRST END IN |
| Disk Loading Method | SPRING |
| Bolt Hole Quantity | 4 FIRST END |
| Material | COPPER ALLOY BODY |
| Material | COPPER ALLOY SEAT |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| 22773PC1T021 PRIMARY | Westinghouse Electric Corp (USA) |
| D2-8854PC781 PRIMARY | Westinghouse Electric Corp (USA) |
| D2-8776PC781 PRIMARY | Westinghouse Electric Corp (USA) |
| D2-8844-781 PRIMARY | Westinghouse Electric Corp (USA) |
| Reference | Meaning |
|---|---|
| 22773 | 5/9 Secondary reference Usm Corp Sub of Emhart Industries Inc Farrel Co Div |
| D2-8776PC781 | 5/9 Secondary reference Westinghouse Electric Corp Control Business Unit |
| D2-8876PC780 | 5/9 Secondary reference Usm Corp Sub of Emhart Industries Inc Farrel Co Div |
| D2-8844-781 | 5/9 Secondary reference Westinghouse Electric Corp Control Business Unit |
| 22773 | 5/9 Secondary reference U.S. Government activity |
| D2-8854PC781 | 5/9 Secondary reference Westinghouse Electric Corp Control Business Unit |
| D2-8443PC781 | 5/9 Secondary reference Usm Corp Sub of Emhart Industries Inc Farrel Co Div |
| PC461S42-31PC781 | 3/2 Design control — primary reference U.S. Government activity |
| PC578S42-251PC781 | 3/2 Design control — primary reference U.S. Government activity |
| D2-8476PC781 | 5/9 Secondary reference Usm Corp Sub of Emhart Industries Inc Farrel Co Div |
| 22773PC1T021 | 5/9 Secondary reference Westinghouse Electric Corp Control Business Unit |
| PC578S42-146PC781 | 3/2 Design control — primary reference U.S. Government activity |
| PC578S42-263-781 | 3/2 Design control — primary reference U.S. Government activity |
| PC461S42-068PC1T021 | 3/2 Design control — primary reference U.S. Government activity |
| PC461S42-06PC781 | 3/2 Design control — primary reference U.S. Government activity |
NSN 4820-00-289-4384 is a Valve,safety Relief, manufactured by Westinghouse Electric Corp, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-289-4384 has 4 manufacturer part numbers on file: 22773PC1T021 (Westinghouse Electric Corp), D2-8854PC781 (Westinghouse Electric Corp), D2-8776PC781 (Westinghouse Electric Corp), D2-8844-781 (Westinghouse Electric Corp).
3 possible matches (shared part number, not a government interchangeability claim): 1650-00-891-3766, 1650-00-925-4744, 4820-01-194-6880. Verify interchangeability with system specifications before substitution.
Key specifications for 22773PC1T021: Flange Shape: ROUND WITH HOLES FIRST END; Flange Face Design: PLAIN FIRST END; Bolt Circle Nominal Diameter: 4.438 INCHES FIRST END IN; Connection Type: FLANGE FIRST END. 13 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.