The Heater,duct Type,stationary, cataloged under National Stock Number 4520-01-421-6831, is classified within Federal Supply Class 4520 (Space and Water Heating Equipment) of the Plumbing, Heating, and Waste Disposal group. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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.
| Item Name | Heater,duct Type,stationary |
| FSC / FSG | 4520 — Space and Water Heating Equipment (FSG 45) |
| Parameter | Value |
|---|---|
| NSN | 4520-01-421-6831 |
| Item Name | Heater,duct Type,stationary |
| FSC / FSG | 4520 / 45 — Space and Water Heating Equipment |
| Status | ACTIVE |
| 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 |
|---|---|
| L210T0:B12983-D-TFZU-1.5-12X6-4- | 3/1 Design control — primary reference Indeeco Llc Dba Indeeco |
| TFZU-1.50-12-6-440/1/1/24 | C/1 Advisory reference — outside the item-of-supply concept Indeeco Llc Dba Indeeco |
| L210T0:B12983-D -0 EL-77103 TAG | C/1 Advisory reference — outside the item-of-supply concept Zf Industrieantriebe Witten Gmbh |
| L210T0:B12983-D | D/9 Drawing number reference only Indeeco Llc Dba Indeeco |
NSN 4520-01-421-6831 is a Heater,duct Type,stationary, classified under FSC 4520, Space and Water Heating Equipment. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 4520-01-421-6834. Verify interchangeability with system specifications before substitution.
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.