# NSN 4520-01-278-9931: Reducer, Air Conditioning-Heating

NSN 4520-01-278-9931 (also written 4520012789931; NIIN 01-278-9931) is a reducer, air conditioning-heating in Federal Supply Class 4520, Space and Water Heating Equipment. 3 manufacturer part numbers from 2 suppliers are on record. No purchases are on record yet.

## Identification

- NSN: 4520-01-278-9931 (4520012789931)
- NIIN: 01-278-9931 (012789931)
- Item name: REDUCER,AIR CONDITIONING-HEATING
- Federal Supply Class: [FSC 4520 Space and Water Heating Equipment](https://nsnexplorer.com/fsc/4520/)
- Federal Supply Group: [FSG 45](https://nsnexplorer.com/group/45/)
- Acquisition method suffix code: AMSC Z: a commercial, nondevelopmental or off-the-shelf item. (observed 2026-10-10)
- Acquisition method code: 3

## Characteristics

| Code | Requirement | Reply |
| --- | --- | --- |
| ABHP | OVERALL LENGTH | INCHES NOMINAL 12.880 |
| ABMK | OVERALL WIDTH | INCHES NOMINAL 5.960 |
| CSLX | FITTING OVERALL LENGTH | INCHES NOMINAL 2.260 |
| CSZC | MAIN TRUNK INLET DIAMETER | INCHES NOMINAL 10.880 |
| CXBF | MAIN TRUNK REDUCING OUTLET DIAMETER | INCHES NOMINAL 6.000 |
| FEAT | SPECIAL FEATURES | FLANGED CONNECTIONS |
| STYL | STYLE DESIGNATOR | — |

## Part numbers

| Part number | CAGE | Supplier | Source |
| --- | --- | --- | --- |
| 5599989 | 53711 | NAVAL SEA SYSTEMS COMMAND | [flis](https://www.dla.mil/Portals/104/Documents/InformationOperations/LogisticsInformationServices/FOIA/PUBLOG/) |
| 5599989-9 | 38597 | LOCKHEED MARTIN CORPORATION DIV ROTARY AND MISSION SYSTEMS | [flis](https://www.dla.mil/Portals/104/Documents/InformationOperations/LogisticsInformationServices/FOIA/PUBLOG/) |
| 5599989-9 | 53711 | NAVAL SEA SYSTEMS COMMAND | [flis](https://www.dla.mil/Portals/104/Documents/InformationOperations/LogisticsInformationServices/FOIA/PUBLOG/) |

## Sources

- DLA DIBBS RFQs for this NSN: https://www.dibbs.bsm.dla.mil/RFQ/RFQNsn.aspx?value=4520012789931&category=nsn
- DLA DIBBS awards for this NSN: https://www.dibbs.bsm.dla.mil/Awards/AwdRecs.aspx?category=awdnsn&TypeSrch=cq&Value=4520012789931
- AMSC record: https://www.dla.mil/Portals/104/Documents/InformationOperations/LogisticsInformationServices/FOIA/PUBLOG/
- All data is public U.S. government data; every row above links to its source record where one exists.

Canonical page: https://nsnexplorer.com/nsn/4520-01-278-9931/
JSON: https://nsnexplorer.com/api/nsn/4520-01-278-9931.json