The Muffler,exhaust, cataloged under National Stock Number 2990-00-488-8639, is classified within Federal Supply Class 2990 (Miscellaneous Engine Accessories, Nonaircraft) of the Engine Accessories group. Government technical data includes 21 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 2990-00-488-8639 |
| Item Name | Muffler,exhaust |
| FSC / FSG | 2990 / 29 — Miscellaneous Engine Accessories, Nonaircraft |
| Status | ACTIVE |
| Outlet Thread Size | 2-11-1/2 FIRST OUTLET |
| Inlet Location | OFFSET LOCATED ON END OF BODY |
| Coolant Type | AIR |
| Design Type | DRY |
| Overall Diameter | 6.000 INCHES NOMINAL IN |
| Outlet Thread Direction | RIGHT-HAND FIRST OUTLET |
| Inlet Thread Location | EXTERNAL SINGLE INLET |
| Inlet Projection Length | 2.000 INCHES NOMINAL SINGLE INLET IN |
| Outlet Thread Series Designator | NPT FIRST OUTLET |
| Muffler Design | MULTIPASS |
| Thread Location | EXTERNAL FIRST OUTLET |
| Tube Quantity | 2 |
| Inlet Connection Type | THREADED SINGLE INLET |
| Thread Direction | RIGHT-HAND SINGLE INLET |
| Body Shape | ROUND |
| Inlet Thread Size | 2-11-1/2 SINGLE INLET |
| Inlet Thread Series Designator | NPT SINGLE INLET |
| Material | STEEL LOCATION NOT OTHERWISE SPECIFIED |
| Outlet Projection Length | 2.000 INCHES NOMINAL FIRST OUTLET IN |
| Outlet Connection Type | THREADED FIRST OUTLET |
| Outlet Location | OFFSET LOCATED ON END OF BODY |
| 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 |
|---|---|
| 1421D158-8 | 5/9 Secondary reference Aero Energy Systems Inc |
| 620GS2 | 3/9 Design control — primary reference U.S. Government activity |
NSN 2990-00-488-8639 is a Muffler,exhaust, classified under FSC 2990, Miscellaneous Engine Accessories, Nonaircraft. Status: active.
Key specifications for 2990-00-488-8639: Outlet Thread Size: 2-11-1/2 FIRST OUTLET; Inlet Location: OFFSET LOCATED ON END OF BODY; Coolant Type: AIR; Design Type: DRY. 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.