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8404.10.00.10

Auxiliary plant for use with boilers of heading 8402 or 8403 / Economizers

Classification path

  1. Auxiliary plant for use with boilers of heading 8402 or 8403 (for example, economizers, super-heaters, soot removers, gas recoverers); condensers for steam or other vapor power units; parts thereof
  2. Auxiliary plant for use with boilers of heading 8402 or 8403
  3. Economizers

Rates of duty

General (MFN)
3.5%
Column 2Cuba, North Korea, Russia, Belarus
45%
Unit of quantity
t

Trade agreement rates

FreeGSP (lapsed since Dec 31, 2020), U.S.-Australia FTA, U.S.-Bahrain FTA, U.S.-Chile FTA, U.S.-Colombia TPA, AGOA (authorized through Dec 31, 2026), E, U.S.-Israel FTA, U.S.-Jordan FTA, U.S.-Korea FTA, U.S.-Morocco FTA, U.S.-Oman FTA, CAFTA-DR, U.S.-Panama TPA, U.S.-Peru TPA, USMCA, U.S.-Singapore FTA

Related lines in heading 8404

About heading 8404

Auxiliary plant for use with boilers of heading 8402 or 8403 (for example, economizers, super-heaters, soot removers, gas recoverers); condensers for steam or other vapor power units; parts thereof

Heading 8404 covers auxiliary equipment that works with steam or vapor boilers of heading 8402 or 8403, such as economizers, super-heaters, soot removers and gas recoverers, plus condensers for steam or other vapor power units. It also covers parts for that equipment. The heading splits into three subheadings: 8404.10 for auxiliary boiler plant, 8404.20 for condensers, and 8404.90 for parts.

Full guide to heading 8404

Products in this heading

  • Boiler economizers that preheat feedwater using flue gas
  • Super-heaters that raise steam temperature above saturation
  • Soot removers and soot blowers for boiler tubes
  • Gas recoverers that capture heat or gas from boiler exhaust
  • Surface condensers for steam turbine power units
  • Shell and tube condensers used in vapor power cycles
  • Replacement tube bundles or shells for boiler economizers
  • Parts for condenser and auxiliary boiler plant equipment

Frequently asked questions

What is the HTS code for a boiler economizer?

Boiler economizers are classified under 8404.10.00.10, which carries a general (MFN) rate of 3.5%.

What is the duty on steam condensers for power units?

Condensers for steam or other vapor power units are classified under 8404.20.00.00 and pay a general (MFN) rate of 5%.

How do I classify a part for boiler auxiliary plant?

Parts for the equipment of heading 8404 are classified under 8404.90.00.00 at a general (MFN) rate of 3.5%. If the item is itself an auxiliary unit such as a soot remover, classify it in 8404.10.00.50 at 3.5%.

Source: USITC Harmonized Tariff Schedule, retrieved October 21, 2026.

HTS 8404.10.00.10: Auxiliary plant for use with boilers of heading 8402 or 840..., 3.5% duty | HTSBase