The Muffler,exhaust, cataloged under National Stock Number 2990-00-900-9688, is classified within Federal Supply Class 2990 (Miscellaneous Engine Accessories, Nonaircraft) of the Engine Accessories group. The manufacturer of record is Donaldson Company, Inc.. Government technical data includes 24 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through both NSN and commercial part number lookups. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 2990-00-900-9688 |
| Primary Part Number | MAM04-5071 |
| Item Name | Muffler,exhaust |
| FSC / FSG | 2990 / 29 — Miscellaneous Engine Accessories, Nonaircraft |
| Manufacturer | Donaldson Company, Inc. |
| Status | ACTIVE |
| Inlet Flange Shape | OVAL SINGLE INLET |
| Operating Position | VERTICAL OR HORIZONTAL |
| FSC Application Data | MISCELLANEOUS ENGINE ACCESSORIES,NONAIRCRAFT |
| Inlet Location | CENTRALLY IN END SECTION OF BODY |
| Coolant Type | AIR |
| Design Type | DRY |
| Overall Diameter | 4.380 INCHES NOMINAL IN |
| Center to Center Distance Between Mounting Holes | 2.688 IN. CENTER TO CENTER DIM OF HOLES SINGLE INLET IN |
| Outlet Inside Diameter | 1.520 INCHES NOMINAL FIRST OUTLET IN |
| Inlet Projection Length | 1.000 INCHES NOMINAL SINGLE INLET IN |
| Baffle Quantity | 1 |
| Inlet Flange Mounting Hole Diameter | 0.410 INCHES NOMINAL SINGLE INLET IN |
| Muffler Design | BAFFLE |
| Outlet Outside Diameter | 1.620 INCHES NOMINAL FIRST OUTLET IN |
| Tube Quantity | 2 |
| Inlet Connection Type | FLANGE SINGLE INLET |
| Body Shape | ROUND |
| Inlet Flange Mounting Provision and Quantity | 2 HOLES SINGLE INLET |
| Unable to Decode | UNABLE TO DECODE |
| Surface Treatment | ALUMINUM ALLOY |
| Material | STEEL LOCATION NOT OTHERWISE SPECIFIED |
| Outlet Projection Length | 2.375 INCHES NOMINAL FIRST OUTLET IN |
| Outlet Connection Type | UNTHREADED FIRST OUTLET |
| Outlet Location | 2-3/4 IN. FROM AND AT 90 DEG ANGLE TO INLET END IN |
| 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 |
|---|---|
| MAM04-5071 PRIMARY | Donaldson Company, Inc. (USA) |
| Reference | Meaning |
|---|---|
| B47466 | 5/9 Secondary reference Davey Compressor Co Div of Keco Industries Inc |
| MAM04-5055 | 5/9 Secondary reference Donaldson Company, Inc. |
| B47466 | 5/2 Secondary reference U.S. Government activity |
| B5-45-3165 | 5/9 Secondary reference U.S. Government activity |
| B47466 | 5/9 Secondary reference Drs Environmental Systems Inc |
NSN 2990-00-900-9688 is a Muffler,exhaust, manufactured by Donaldson Company, Inc., classified under FSC 2990, Miscellaneous Engine Accessories, Nonaircraft. Status: active.
NSN 2990-00-900-9688 has 1 manufacturer part number on file: MAM04-5071 (Donaldson Company, Inc.).
Key specifications for MAM04-5071: Inlet Flange Shape: OVAL SINGLE INLET; Operating Position: VERTICAL OR HORIZONTAL; FSC Application Data: MISCELLANEOUS ENGINE ACCESSORIES,NONAIRCRAFT; Inlet Location: CENTRALLY IN END SECTION OF BODY. 24 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.