The Heater,water,liquid Fuel, cataloged under National Stock Number 4520-00-203-3583, is classified within Federal Supply Class 4520 (Space and Water Heating Equipment) of the Plumbing, Heating, and Waste Disposal group. Government technical data includes 5 specifications, cited from the U.S. Government catalog. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4520-00-203-3583 |
| Item Name | Heater,water,liquid Fuel |
| FSC / FSG | 4520 / 45 — Space and Water Heating Equipment |
| Status | ACTIVE |
| General Characteristics Item Description | HIGH PRESSURE,ATOMIZING BURNER; DESIGNED FOR FUEL OIL,GRADE NO. 2,PER FED SPCE VV-F-815; HEATING CAPACITY DATA,100 GAL WATER HEATED PER HR,100 DEG F TEMP RISE PER HR; STORAGE TANK DATA,DESIGNED FOR VERTICAL POS,30 GAL CAPACITY,STEEL,PROTECTIVE FINSIH DATA,EXTERIOR FINISH,A/A,FUSED GLASS INTERIOR FINISH; AUTOMATICALLY CONTROLLED; NOT RATED FOR MAX WP; WATER CONNECTIONS DATA,INLET,1,3/4 IN.-14 NPT,OUTLET,1,3/4 IN.-14 NPT; DESIGNED FOR 6 IN. FLUE PIPE; INSULATED; OVER-ALL DIMENSIONS,A/A IN. H,A/A IN. DIA; ADDITIONAL EQUIPMENT,COMBINATION PRESSURE AND TEMPERATURE RELIEF VALVE 1,DRAFT REGULATOR 1,ELBOW,FLUE PIPE,90 DEG 1,PIPE,FLUE,2 FT LONG 7,SPARE OIL BURNER,IGNITION ELECTRODES W/LEADS 1 PR,STORM COLLAR,FLUE PIPE 1; SPECIAL FEATURES,127.5 MIN WP IN |
| Departure From Cited Designator | ADDITIONAL EQUIPMENT,SPECIAL FEATURES |
| Nondefinitive Spec/std Data | 1 TYPE |
| Nondefinitive Spec/std Data | B STYLE |
| Nondefinitive Spec/std Data | 30 SIZE |
| 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 |
|---|---|
| AA50549-04-35 | 3/2 Design control — primary reference U.S. Government activity |
| AA50549-04-35 | 5/9 Secondary reference U.S. Government activity |
| MIL-H-16451 | 5/9 Secondary reference U.S. Government activity |
NSN 4520-00-203-3583 is a Heater,water,liquid Fuel, classified under FSC 4520, Space and Water Heating Equipment. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 4520-00-232-7446. Verify interchangeability with system specifications before substitution.
Key specifications for 4520-00-203-3583: General Characteristics Item Description: HIGH PRESSURE,ATOMIZING BURNER; DESIGNED FOR FUEL OIL,GRADE NO. 2,PER FED SPCE VV-F-815; HEATING CAPACITY DATA,100 GAL WATER HEATED PER HR,100 DEG F TEMP RISE PER HR; STORAGE TANK DATA,DESIGNED FOR VERTICAL POS,30 GAL CAPACITY,STEEL,PROTECTIVE FINSIH DATA,EXTERIOR FINISH,A/A,FUSED GLASS INTERIOR FINISH; AUTOMATICALLY CONTROLLED; NOT RATED FOR MAX WP; WATER CONNECTIONS DATA,INLET,1,3/4 IN.-14 NPT,OUTLET,1,3/4 IN.-14 NPT; DESIGNED FOR 6 IN. FLUE PIPE; INSULATED; OVER-ALL DIMENSIONS,A/A IN. H,A/A IN. DIA; ADDITIONAL EQUIPMENT,COMBINATION PRESSURE AND TEMPERATURE RELIEF VALVE 1,DRAFT REGULATOR 1,ELBOW,FLUE PIPE,90 DEG 1,PIPE,FLUE,2 FT LONG 7,SPARE OIL BURNER,IGNITION ELECTRODES W/LEADS 1 PR,STORM COLLAR,FLUE PIPE 1; SPECIAL FEATURES,127.5 MIN WP IN; Departure From Cited Designator: ADDITIONAL EQUIPMENT,SPECIAL FEATURES; Nondefinitive Spec/std Data: 1 TYPE; Nondefinitive Spec/std Data: B STYLE. 5 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.