The Valve,safety Relief, cataloged under National Stock Number 4820-00-446-3543, 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 30 specifications, cited from the U.S. Government catalog. The record lists 5 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-00-446-3543 |
| Primary Part Number | 26J535PC1T023 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Westinghouse Electric Corp |
| Status | ACTIVE |
| Flow Control Device | DISKDISK |
| Flange Shape | ROUND WITH HOLES SECOND ENDROUND WITH HOLES SECOND END |
| Nominal Pipe Size Accommodated | 1.250 INCHES FIRST END1.250 INCHES FIRST END IN |
| Flange Face Design | PLAIN SECOND END |
| Connection Style | PLAIN,OPTIONAL END(PIPE) FIRST ENDPLAIN,OPTIONAL END(PIPE) FIRST END |
| Bolt Circle Nominal Diameter | 3.125 INCHES SECOND END IN |
| Connection Type | THREADED INTERNAL PIPE FIRST ENDTHREADED INTERNAL PIPE FIRST END |
| Connection Type | FLANGE SECOND ENDFLANGE SECOND END |
| Style Designator | ANGLE FLANGED ENDS |
| Bolt Hole Nominal Diameter | 0.562 INCHES SECOND END IN |
| Operating Pressure | 100.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Valve Size | 1.000 INCHES1.000 INCHES IN |
| Adjustable Pressure Range | +7.0 TO 25.0 POUNDS PER SQUARE INCH+7.0 TO 25.0 POUNDS PER SQUARE INCH LBS |
| Bonnet Type | INSIDE SPRINGINSIDE SPRING |
| Thread Direction | RIGHT-HAND FIRST ENDRIGHT-HAND FIRST END |
| Nominal Thread Size | 1.250 INCHES FIRST END1.250 INCHES FIRST END IN |
| Maximum Operating Temp | 425.0 FAHRENHEIT SINGLE RESPONSE425.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Second Connection Face to Centerline Distance | 1.906 INCHES IN |
| Nominal Outside Diameter | 4.250 INCHES SECOND END IN |
| Disk Loading Method | SPRINGSPRING |
| Bolt Hole Quantity | 4 SECOND END4 SECOND END |
| Bonnet Attachment Method | THREADEDTHREADED |
| Media for Which Designed | STEAM SINGLE RESPONSE |
| First Connection Face to Centerline Distance | 3.000 INCHES IN |
| Material | NICKEL ALLOY STEM |
| Material | NICKEL ALLOY STEMNICKEL ALLOY FLOW CONTROL DEVICE |
| Material | NICKEL ALLOY FLOW CONTROL DEVICENICKEL ALLOY SEAT |
| Material | NICKEL ALLOY SEATCOPPER ALLOY BODY |
| Thread Series Designator | NPT FIRST END |
| Valve Operation Method | AUTOMATIC OR AUTOMATIC OR MANUALMANUAL |
| 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 |
|---|---|
| 26J535PC1T023 PRIMARY | Westinghouse Electric Corp (USA) |
| 27J409PC1T023 PRIMARY | Westinghouse Electric Corp (USA) |
| 26J539PC52 PRIMARY | Westinghouse Electric Corp (USA) |
| 1110323 PRIMARY | Westinghouse Electric Corp (USA) |
| 26J610PC1T023 PRIMARY | Westinghouse Electric Corp (USA) |
| Reference | Meaning |
|---|---|
| 26J535PC1T023 | 5/9 Secondary reference Westinghouse Electric Corp Control Business Unit |
| 27J409PC1T023 | 5/9 Secondary reference Westinghouse Electric Corp Control Business Unit |
| 26J539PC52 | 5/9 Secondary reference Westinghouse Electric Corp Control Business Unit |
| 1110323 | 5/9 Secondary reference Westinghouse Electric Corp Control Business Unit |
| 26J610PC1T023 | 5/9 Secondary reference Westinghouse Electric Corp Control Business Unit |
NSN 4820-00-446-3543 is a Valve,safety Relief, manufactured by Westinghouse Electric Corp, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-446-3543 has 5 manufacturer part numbers on file: 26J535PC1T023 (Westinghouse Electric Corp), 27J409PC1T023 (Westinghouse Electric Corp), 26J539PC52 (Westinghouse Electric Corp), 1110323 (Westinghouse Electric Corp), 26J610PC1T023 (Westinghouse Electric Corp).
Key specifications for 26J535PC1T023: Flow Control Device: DISKDISK; Flange Shape: ROUND WITH HOLES SECOND ENDROUND WITH HOLES SECOND END; Nominal Pipe Size Accommodated: 1.250 INCHES FIRST END1.250 INCHES FIRST END IN; Flange Face Design: PLAIN SECOND END. 30 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.