The Valve,safety Relief, cataloged under National Stock Number 4820-01-277-8403, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Anderson Greenwood Lp Dba Anderson Greenwood Crosby. Government technical data includes 24 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 3 items share a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-277-8403 |
| Primary Part Number | 0020-C02-MC0269 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Anderson Greenwood Lp Dba Anderson Greenwood Crosby |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Furnished Items and Quantity | 1 CAP |
| Connection Style | PLAIN,OPTIONAL END(PIPE) SECOND END |
| Connection Style | PLAIN (PIPE) FIRST END |
| Connection Type | THREADED INTERNAL PIPE SECOND END |
| Connection Type | THREADED EXTERNAL PIPE FIRST END |
| Style Designator | ANGLE |
| Operating Pressure | 300.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Adjustable Pressure Range | +242.0 TO 290.0 POUNDS PER SQUARE INCH LBS |
| Bonnet Type | INSIDE SPRING |
| Thread Direction | RIGHT-HAND SECOND END |
| Thread Direction | RIGHT-HAND FIRST END |
| Nominal Thread Size | 0.500 INCHES SECOND END IN |
| Nominal Thread Size | 0.500 INCHES FIRST END IN |
| Maximum Operating Temp | 450.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Bonnet Attachment Method | THREADED |
| Media for Which Designed | WATER-OIL-GAS SINGLE RESPONSE |
| Material | BRONZE BODY |
| Material | BRONZE FLOW CONTROL DEVICE |
| Material | COPPER ALLOY SEAT |
| Thread Series Designator | NPT SECOND END |
| Thread Series Designator | NPT FIRST END |
| Valve Operation Method | AUTOMATIC |
| 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 |
|---|---|
| 0020-C02-MC0269 PRIMARY | Anderson Greenwood Lp Dba Anderson Greenwood Crosby (USA) |
| Reference | Meaning |
|---|---|
| 214675 | D/9 Drawing number reference only Dresser, Inc. Dba Dresser Equipment Group Div Industrial Valve Operations, Dresse |
| 1471 | D/9 Drawing number reference only Dresser, Inc. Dba Dresser Equipment Group Div Industrial Valve Operations, Dresse |
| 1471-1/2IN | 5/9 Secondary reference Dresser, Inc. Dba Dresser Equipment Group Div Industrial Valve Operations, Dresse |
| 214675-1/2IN-242T 290PSI | 5/9 Secondary reference Dresser, Inc. Dba Dresser Equipment Group Div Industrial Valve Operations, Dresse |
NSN 4820-01-277-8403 is a Valve,safety Relief, manufactured by Anderson Greenwood Lp Dba Anderson Greenwood Crosby, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-277-8403 has 1 manufacturer part number on file: 0020-C02-MC0269 (Anderson Greenwood Lp Dba Anderson Greenwood Crosby).
3 possible matches (shared part number, not a government interchangeability claim): 4820-01-277-8478, 4820-01-278-3718, 4820-01-322-6603. Verify interchangeability with system specifications before substitution.
Key specifications for 0020-C02-MC0269: Flow Control Device: DISK; Furnished Items and Quantity: 1 CAP; Connection Style: PLAIN,OPTIONAL END(PIPE) SECOND END; Connection Style: PLAIN (PIPE) FIRST END. 24 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.