The Valve,safety Relief, cataloged under National Stock Number 4820-00-357-4899, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Mueller Refrigeration Products Co. Government technical data includes 12 specifications, cited from the U.S. Government catalog. The record lists 2 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-00-357-4899 |
| Primary Part Number | AG-15503 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Mueller Refrigeration Products Co |
| Status | ACTIVE |
| Nominal Pipe Size Accommodated | 0.375 INCHES SECOND END IN |
| Connection Style | FLARED (TUBE) FIRST END |
| Connection Style | GASKET SEAL (PIPE) SECOND END |
| Connection Type | THREADED EXTERNAL PIPE SECOND END |
| Connection Type | THREADED EXTERNAL TUBE FIRST END |
| Nominal Outside Diameter Tube Accommodated | 0.500 INCHES FIRST END IN |
| Adjustable Pressure Range | +150.0 TO 450.0 POUNDS PER SQUARE INCH LBS |
| Thread Direction | RIGHT-HAND SECOND END |
| Thread Direction | RIGHT-HAND FIRST END |
| Material | COPPER ALLOY BODY |
| Opening Pressure Setting | 415.0 POUNDS PER SQUARE INCH LBS |
| Valve Operation Method | HYDRAULIC |
| 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 |
|---|---|
| AG-15503 PRIMARY | Mueller Refrigeration Products Co (USA) |
| AG-15503 | Hughes Albright Fletz and Natle Reporting Services Inc (USA) |
| Reference | Meaning |
|---|---|
| 5231A | 5/9 Secondary reference Henry Technologies, Inc. |
| 5231A SET@ 350P | C/1 Advisory reference — outside the item-of-supply concept Henry Technologies, Inc. |
NSN 4820-00-357-4899 is a Valve,safety Relief, manufactured by Mueller Refrigeration Products Co, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-357-4899 has 2 manufacturer part numbers on file: AG-15503 (Mueller Refrigeration Products Co), AG-15503 (Hughes Albright Fletz and Natle Reporting Services Inc).
1 possible match (shared part number, not a government interchangeability claim): 4820-01-301-7297. Verify interchangeability with system specifications before substitution.
Key specifications for AG-15503: Nominal Pipe Size Accommodated: 0.375 INCHES SECOND END IN; Connection Style: FLARED (TUBE) FIRST END; Connection Style: GASKET SEAL (PIPE) SECOND END; Connection Type: THREADED EXTERNAL PIPE SECOND END. 12 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.