The Muffler,exhaust, cataloged under National Stock Number 2990-00-221-5810, is classified within Federal Supply Class 2990 (Miscellaneous Engine Accessories, Nonaircraft) of the Engine Accessories group. The manufacturer of record is C V C Enterprises. Government technical data includes 21 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 2990-00-221-5810 |
| Primary Part Number | 2520 |
| Item Name | Muffler,exhaust |
| FSC / FSG | 2990 / 29 — Miscellaneous Engine Accessories, Nonaircraft |
| Manufacturer | C V C Enterprises |
| Status | ACTIVE |
| Inlet Flange Shape | SQUARE SINGLE INLET |
| Operating Position | UNIVERSAL |
| Outlet Thread Size | 4-8 FIRST OUTLET |
| Inlet Location | LOCATED AT B0TTOM IN END SECTION OF BODY |
| Coolant Type | AIR |
| Design Type | DRY |
| Outlet Thread Direction | RIGHT-HAND FIRST OUTLET |
| Center to Center Distance Between Mounting Holes | 4-1/8 IN. C TO C DIM. OF MTG HOLES SINGLE INLET IN |
| Inlet Projection Length | 2.500 INCHES NOMINAL SINGLE INLET IN |
| Outlet Thread Series Designator | NPT FIRST OUTLET |
| Material Document and Classification | MIL-S-46055 MIL SPEC SINGLE MATERIAL RESPONSE LOCATION NOT OTHERWISE SPECIFIED |
| Inlet Flange Mounting Hole Diameter | 0.532 INCHES MINIMUM AND 0.562 INCHES MAXIMUM SINGLE INLET IN |
| Thread Location | EXTERNAL FIRST OUTLET |
| Inlet Connection Type | FLANGE SINGLE INLET |
| Body Shape | OVAL |
| Inlet Flange Mounting Provision and Quantity | 4 HOLES SINGLE INLET |
| Surface Treatment | CHROMATE |
| Material | STEEL LOCATION NOT OTHERWISE SPECIFIED |
| Outlet Projection Length | 12.760 INCHES MINIMUM AND 13.000 INCHES MAXIMUM FIRST OUTLET IN |
| Outlet Connection Type | THREADED FIRST OUTLET |
| Outlet Location | LOCATED AT TOP IN END SECTION OF BODY OPPOSITE INLET |
| 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 |
|---|---|
| 2520 PRIMARY | C V C Enterprises (USA) |
| Reference | Meaning |
|---|---|
| 2520 | 5/9 Secondary reference U.S. Government activity |
| 71-4934 | 7/2 Vendor item drawing reference Department of Defense Project Manager-Mobile Electric Power |
NSN 2990-00-221-5810 is a Muffler,exhaust, manufactured by C V C Enterprises, classified under FSC 2990, Miscellaneous Engine Accessories, Nonaircraft. Status: active.
NSN 2990-00-221-5810 has 1 manufacturer part number on file: 2520 (C V C Enterprises).
1 possible match (shared part number, not a government interchangeability claim): 5330-01-033-4585. Verify interchangeability with system specifications before substitution.
Key specifications for 2520: Inlet Flange Shape: SQUARE SINGLE INLET; Operating Position: UNIVERSAL; Overall Height: 10.060 INCHES MINIMUM AND 10.180 INCHES MAXIMUM IN; Outlet Thread Size: 4-8 FIRST OUTLET. 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.