The Heater,duct Type,stationary, cataloged under National Stock Number 4520-01-212-7550, is classified within Federal Supply Class 4520 (Space and Water Heating Equipment) of the Plumbing, Heating, and Waste Disposal group. The manufacturer of record is Chromalox Inc Dba Chromalox Precision Heat and Control, Inc. Government technical data includes 16 specifications, cited from the U.S. Government catalog. The record lists 3 manufacturer part numbers 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4520-01-212-7550 |
| Primary Part Number | 106-056816-006 |
| Item Name | Heater,duct Type,stationary |
| FSC / FSG | 4520 / 45 — Space and Water Heating Equipment |
| Manufacturer | Chromalox Inc Dba Chromalox Precision Heat and Control, Inc |
| Status | ACTIVE |
| Heat Delivery Rate | 6482.8 BRITISH THERMAL UNIT |
| Phase | THREE |
| Frequency in Hertz | 50.0 OR 60.0 |
| Current Type | AC |
| Heat Medium Type | AIR |
| Inclosure Material | STEEL |
| Voltage in Volts | 115.0 |
| Specification/standard Data | 81349-MIL-H-22594 GOVERNMENT SPECIFICATION |
| Nondefinitive Spec/std Data | 21EH SIZE OR H TYPE |
| Height | 6.250 INCHES NOMINAL IN |
| Surface Treatment | ZINC |
| Depth | 6.000 INCHES NOMINAL IN |
| Width | 13.000 INCHES NOMINAL IN |
| Mounting Type | VENTILATION DUCT |
| Heating Element Type | ELECTRIC NONIMMERSION |
| Current Rating in Amps | 16.5 |
| 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 |
|---|---|
| EH-21H | Valad Electric Heating Corp. (USA) |
| TFZ-21H | Indeeco Llc Dba Indeeco (USA) |
| 106-056816-006 PRIMARY | Chromalox Inc Dba Chromalox Precision Heat and Control, Inc (USA) |
| Reference | Meaning |
|---|---|
| 106-056816-000 | D/9 Drawing number reference only Chromalox Inc Dba Chromalox Precision Heat and Control, Inc |
| MIL-H-22594 | 4/1 Identification reference U.S. Government activity |
NSN 4520-01-212-7550 is a Heater,duct Type,stationary, manufactured by Chromalox Inc Dba Chromalox Precision Heat and Control, Inc, classified under FSC 4520, Space and Water Heating Equipment. Status: active.
NSN 4520-01-212-7550 has 3 manufacturer part numbers on file: EH-21H (Valad Electric Heating Corp.), TFZ-21H (Indeeco Llc Dba Indeeco), 106-056816-006 (Chromalox Inc Dba Chromalox Precision Heat and Control, Inc).
Key specifications for 106-056816-006: Heat Delivery Rate: 6482.8 BRITISH THERMAL UNIT; Phase: THREE; Frequency in Hertz: 50.0 OR 60.0; Current Type: AC. 16 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.