The Valve,safety Relief, cataloged under National Stock Number 4820-01-321-7248, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 21 specifications, cited from the U.S. Government catalog. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-321-7248 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flange Shape | ROUND FIRST END |
| Flange Shape | ROUND WITH HOLES SECOND END |
| Flange Face Design | RAISED STRAIGHT SECOND END |
| Flange Face Design | PLAIN FIRST END |
| Bolt Circle Nominal Diameter | 5.375 INCHES SECOND END IN |
| Connection Type | FLANGE SECOND END |
| Connection Type | FLANGE FIRST END |
| Style Designator | ANGLE FLANGED ENDS |
| Material Document and Classification | ASME SA479,TY 316 ASSN STD 1ST MATERIAL RESPONSE AND ASTM A276,TY 440C GR 100 ASSN STD 2ND MATERIAL RESPONSE FLOW CONTROL DEVICE |
| Material Document and Classification | ASME SA479,TY 316 ASSN STD SINGLE MATERIAL RESPONSE BODY |
| Bolt Hole Nominal Diameter | 0.438 INCHES SECOND END IN |
| Second Connection Face to Centerline Distance | 4.188 INCHES IN |
| Disk Loading Method | SPRING |
| Bolt Hole Quantity | 4 SECOND END |
| Media for Which Designed | AIR SINGLE RESPONSE |
| First Connection Face to Centerline Distance | 4.469 INCHES IN |
| Material | STEEL COMP 316 BODY |
| Material | STEEL CORROSION RESISTING FLOW CONTROL DEVICE |
| Opening Pressure Setting | 810.0 POUNDS PER SQUARE INCH LBS |
| Valve Discharge Flow Rate | 9451.0 CUBIC FEET PER MINUTE |
| 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 |
| Reference | Meaning |
|---|---|
| 9431-20-0000-500 PIECE 6 | 5/9 Secondary reference U.S. Government activity |
| 9431-02-5800-496 | 5/9 Secondary reference U.S. Government activity |
| 9431-02-5800-496 | 3/2 Design control — primary reference U.S. Government activity |
| 9431-20-0000-500 PIECE 6 | 5/2 Secondary reference U.S. Government activity |
NSN 4820-01-321-7248 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
2 possible matches (shared part number, not a government interchangeability claim): 4820-01-323-5958, 4820-01-323-6042. Verify interchangeability with system specifications before substitution.
Key specifications for 4820-01-321-7248: Flange Shape: ROUND FIRST END; Flange Shape: ROUND WITH HOLES SECOND END; Flange Face Design: RAISED STRAIGHT SECOND END; Flange Face Design: PLAIN FIRST END. 21 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.