The Elbow,tube, cataloged under National Stock Number 4730-00-540-1522, is classified within Federal Supply Class 4730 (Hose, Pipe, Tube, Lubrication, and Railing Fittings) of the Pipe, Tubing, Hose, and Fittings group. The manufacturer of record is Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney. Government technical data includes 20 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4730-00-540-1522 |
| Primary Part Number | 278121 |
| Item Name | Elbow,tube |
| FSC / FSG | 4730 / 47 — Hose, Pipe, Tube, Lubrication, and Railing Fittings |
| Manufacturer | Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney |
| Status | ACTIVE |
| Flow Angle | 90.0 DEGREES |
| Connection Style | FLARED (TUBE) SECOND END |
| Connection Style | FLARED (TUBE) FIRST END |
| Connection Type | THREADED EXTERNAL TUBE FIRST END |
| Connection Type | THREADED EXTERNAL TUBE SECOND END |
| Material Document and Classification | AMS5640 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Outside Diameter Tube Accommodated | 0.250 INCHES SECOND END IN |
| Nominal Outside Diameter Tube Accommodated | 0.500 INCHES FIRST END IN |
| Leg Length | 1.180 INCHES NOMINAL FIRST END IN |
| Leg Length | 1.120 INCHES NOMINAL SECOND END IN |
| Reduced Passage Nominal Inside Diameter | 0.332 INCHES FIRST END IN |
| Nominal Thread Size | 0.438 INCHES SECOND END IN |
| Nominal Thread Size | 0.750 INCHES FIRST END IN |
| Seat Angle | 37.0 DEGREES SECOND END |
| Seat Angle | 45.0 DEGREES FIRST END |
| Thread Class | 3A FIRST END A |
| Thread Class | 3A SECOND END A |
| Material | STEEL CORROSION RESISTING OVERALL |
| Thread Series Designator | UNF FIRST END |
| Thread Series Designator | UNF SECOND END |
| 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 |
|---|---|
| 278121 PRIMARY | Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney (USA) |
| Reference | Meaning |
|---|---|
| 278121 | 5/9 Secondary reference Royal Oak Gage, Inc |
| 278121 | 5/9 Secondary reference Turbo Power & Marine System Inc Sub of United Technologies Corp |
NSN 4730-00-540-1522 is a Elbow,tube, manufactured by Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney, classified under FSC 4730, Hose, Pipe, Tube, Lubrication, and Railing Fittings. Status: active.
NSN 4730-00-540-1522 has 1 manufacturer part number on file: 278121 (Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney).
1 possible match (shared part number, not a government interchangeability claim): 1720-01-512-1880. Verify interchangeability with system specifications before substitution.
Key specifications for 278121: Flow Angle: 90.0 DEGREES; Connection Style: FLARED (TUBE) SECOND END; Connection Style: FLARED (TUBE) FIRST END; Connection Type: THREADED EXTERNAL TUBE FIRST END. 20 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.