The Valve,safety Relief, cataloged under National Stock Number 4820-01-656-3373, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Cambridge Valve & Fitting, Inc. Dba Cambridge Valve & Fitting Inc. Government technical data includes 16 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. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-656-3373 |
| Primary Part Number | SS-4R3A-SETH |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Cambridge Valve & Fitting, Inc. Dba Cambridge Valve & Fitting Inc |
| Status | ACTIVE |
| Connection Type | THREADED EXTERNAL TUBE FIRST END |
| Connection Type | THREADED INTERNAL TUBE SECOND END |
| Style Designator | ANGLE |
| Material Document and Classification | ASTM A479 ASSN STD SINGLE MATERIAL RESPONSE STEM |
| Material Document and Classification | ASTM A182 ASSN STD SINGLE MATERIAL RESPONSE BODY |
| Material Document and Classification | ASTM A479 ASSN STD SINGLE MATERIAL RESPONSE SEAT |
| Valve Size | 0.25 INCHES IN |
| Adjustable Pressure Range | +5000.00 TO 6000.00 POUNDS PER SQUARE INCH LBS |
| Bonnet Type | INSIDE SPRING |
| Second Connection Face to Centerline Distance | 1.44 INCHES IN |
| Disk Loading Method | SPRING |
| Bonnet Attachment Method | THREADED |
| First Connection Face to Centerline Distance | 1.60 INCHES IN |
| Material | STEEL COMP 316 BODY |
| Material | STEEL COMP 316 SEAT |
| Material | STEEL COMP 316 STEM |
| 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 |
|---|---|
| SS-4R3A-SETH PRIMARY | Cambridge Valve & Fitting, Inc. Dba Cambridge Valve & Fitting Inc (USA) |
| 255-1531 | Kahn Instruments, Incorporated (USA) |
NSN 4820-01-656-3373 is a Valve,safety Relief, manufactured by Cambridge Valve & Fitting, Inc. Dba Cambridge Valve & Fitting Inc, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-656-3373 has 2 manufacturer part numbers on file: SS-4R3A-SETH (Cambridge Valve & Fitting, Inc. Dba Cambridge Valve & Fitting Inc), 255-1531 (Kahn Instruments, Incorporated).
Key specifications for SS-4R3A-SETH: Connection Type: THREADED EXTERNAL TUBE FIRST END; Connection Type: THREADED INTERNAL TUBE SECOND END; Style Designator: ANGLE; Material Document and Classification: ASTM A479 ASSN STD SINGLE MATERIAL RESPONSE STEM. 16 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.