The Heater,fluid,industrial, cataloged under National Stock Number 4420-00-491-8809, is classified within Federal Supply Class 4420 (Heat Exchangers and Steam Condensers) of the Furnace, Steam, Drying, Nuclear Reactors group. Government technical data includes 14 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4420-00-491-8809 |
| Item Name | Heater,fluid,industrial |
| FSC / FSG | 4420 / 44 — Heat Exchangers and Steam Condensers |
| Status | ACTIVE |
| Heat Transfer Method | INDIRECT |
| Length | 192.000 INCHES MAXIMUM IN |
| Connection Type | FLANGED PIPE HEATING FLUID INLET |
| Connection Type | FLANGED PIPE HEATING FLUID OUTLET |
| Style Designator | PLAIN U-TUBE |
| Diameter | 12.000 INCHES MAXIMUM IN |
| Tube Attachment Method | WELDED BOTH ENDS |
| Connection Nominal Diameter | 3.000 INCHES HEATING FLUID INLET IN |
| Connection Nominal Diameter | 3.000 INCHES HEATING FLUID OUTLET IN |
| Departure From Cited Designator | AS MODIFIED BY SPECIAL FEATURES |
| Nondefinitive Spec/std Data | 5 SIZE |
| Height | 48.000 INCHES MAXIMUM IN |
| Rated Capacity at Maximum Working Pressure | 21000.0 GALLONS PER HOUR |
| Material | STEEL OVERALL |
| 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 |
|---|---|
| MILH82000 | 4/1 Identification reference U.S. Government activity |
NSN 4420-00-491-8809 is a Heater,fluid,industrial, classified under FSC 4420, Heat Exchangers and Steam Condensers. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 4420-00-974-1952. Verify interchangeability with system specifications before substitution.
Key specifications for 4420-00-491-8809: Heat Transfer Method: INDIRECT; Length: 192.000 INCHES MAXIMUM IN; Connection Type: FLANGED PIPE HEATING FLUID INLET; Connection Type: FLANGED PIPE HEATING FLUID OUTLET. 14 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.