N357787

N357787 February 3, 2026 CLA-2-84:OT:RR:NC:N1:103 CATEGORY: Classification TARIFF NO.: 8419.89.9585; 8419.90.9580 Jonathan Bellamy A.O. Smith Corporation 500 Tennessee Waltz Parkway Ashland City, TN 37015 RE: The tariff classification of a water-tube type heat exchanger from France and a fire-tube type heat exchanger from Poland Dear Mr. Bellamy: In your letter dated January 14, 2026, you requested a tariff classification ruling. The first item under consideration is identified as a water-tube type heat exchanger, part number 100380645, and is described as an assembly used in various types of heating equipment. Its main components include a burner assembly, a corrugated combustion chamber, a tube assembly, and an outer shell housing. The shell has several dedicated ports: one for introducing an air and gas mixture, another for expelling the flue gas, and two for the circulation of water. During its operation, cold water enters the unit and flows through a tube assembly that runs parallel to the inner wall of the shell. At the center of the shell is a combustion chamber where the gas and air mixture is ignited, a process that creates hot flue gases that heat the water in the tube assembly. The second item under consideration is identified as a fire-tube type heat exchanger, part number 100320797, and is also described as a component used in various types of heating equipment. While its function is similar to the water-tube unit described above, it differs in operation. In the subject fire-tube unit, the hot flue gases generated in the combustion chamber flow through flue tubes and heat the water outside the tubes and in the shell side of the unit. The fire-tube heat exchanger will be imported without the burner assembly. You state that the water-tube type heat exchanger and fire-tube type heat exchanger are primarily used in equipment for hot water production in commercial buildings and hydronic space heating systems. However, they can also be used to heat glycol for swimming pool and spa heating systems, snow melt systems, and other industrial operations. In your submission, you suggest that both the water-tube type heat exchanger and the fire-tube type heat exchanger are classified under subheading 8419.50.5000, Harmonized Tariff Schedule of the United States (HTSUS). While we agree that they are classified in heading 8419, we disagree at the subheading level. The units are not configured as heat exchangers of subheading 8419.50 but are core subassemblies akin to fired heaters for heat-transfer mediums. For example, the water-tube type heat exchanger incorporates its own burner assembly for direct heating. Also, while the fire-tube type heat exchanger is imported without the burner assembly, it cannot perform its function without incorporating a burner assembly, which is installed post-importation. The applicable subheading for the water-tube type heat exchanger, part number 100380645, will be 8419.89.9585, HTSUS, which provides for “Machinery, plant or laboratory equipment, whether or not electrically heated (excluding furnaces, ovens and other equipment of heading 8514), for the treatment of materials by a process involving a change of temperature such as heating, cooking, roasting, distilling, rectifying, sterilizing, pasteurizing, steaming, drying, evaporating, vaporizing, condensing or cooling, other than machinery or plant of a kind used for domestic purposes; instantaneous or storage water heaters, nonelectric; parts thereof: Other machinery, plant or equipment: Other: Other: Other: Other: For other materials.” The general rate of duty will be 4.2 percent ad valorem. The applicable subheading for the fire-tube type heat exchanger, part number 100320797, will be 8419.90.9580, HTSUS, which provides for “Machinery, plant or laboratory equipment, whether or not electrically heated (excluding furnaces, ovens and other equipment of heading 8514), for the treatment of materials by a process involving a change of temperature such as heating, cooking, roasting, distilling, rectifying, sterilizing, pasteurizing, steaming, drying, evaporating, vaporizing, condensing or cooling, other than machinery or plant of a kind used for domestic purposes; instantaneous or storage water heaters, nonelectric; parts thereof: Parts: Other: Other: Other.” The general rate of duty will be 4 percent ad valorem. The duties cited above are current as of this ruling’s issuance. Duty rates are provided for your convenience and are subject to change. The text of the most recent HTSUS and the accompanying duty rates are provided at https://hts.usitc.gov/. This ruling does not address the applicability of any additional duties, taxes, fees, exactions and/or other charges, which may apply to the goods discussed herein. This includes, but is not limited to, tariffs and other duties as provided for in Subchapter III to Chapter 99, HTSUS. Thus, for example, in addition to the classification stated above, the merchandise covered by this ruling may also need to be reported with either the Chapter 99 provision under which an additional tariff applies or one of the Chapter 99 provisions covering exceptions to such tariffs. For further information to assist with the importation process, please refer to the frequently updated Cargo Systems Messaging Service (CSMS) messages at https://www.cbp.gov/trade/automated/cargo-systems-messaging-service and Frequently Asked Questions on the Trade Remedy/IEEPA page at https://www.cbp.gov/trade/programs-administration/trade-remedies/IEEPA-FAQ. The holding set forth above applies only to the specific factual situation and merchandise description as identified in the ruling request. This position is clearly set forth in Title 19, Code of Federal Regulations (CFR), Section 177.9(b)(1). This section states that a ruling letter is issued on the assumption that all of the information furnished in the ruling letter, whether directly, by reference, or by implication, is accurate and complete in every material respect. In the event that the facts are modified in any way, or if the goods do not conform to these facts at time of importation, you should bring this to the attention of U.S. Customs and Border Protection (CBP) and submit a request for a new ruling in accordance with 19 CFR 177.2. Additionally, we note that the material facts described in the foregoing ruling may be subject to periodic verification by CBP. This ruling is being issued under the provisions of Part 177 of the Customs and Border Protection Regulations (19 C.F.R. 177). A copy of the ruling or the control number indicated above should be provided with the entry documents filed at the time this merchandise is imported. If you have any questions regarding the ruling, please contact National Import Specialist Paul Huang at paul.huang@cbp.dhs.gov. Sincerely, (for) Denise Faingar Designated Official Performing the Duties of the Division Director National Commodity Specialist Division

set forth above applies only to the specific factual situation and merchandise description as identified in the ruling request. This position is clearly set forth in Title 19, Code of Federal Regulations (CFR), Section 177.9(b)(1). This section states that a ruling letter is issued on the assumption that all of the information furnished in the ruling letter, whether directly, by reference, or by implication, is accurate and complete in every material respect. In the event that the facts are modified in any way, or if the goods do not conform to these facts at time of importation, you should bring this to the attention of U.S. Customs and Border Protection (CBP) and submit a request for a new ruling in accordance with 19 CFR 177.2. Additionally, we note that the material facts described in the foregoing ruling may be subject to periodic verification by CBP. This ruling is being issued under the provisions of Part 177 of the Customs and Border Protection Regulations (19 C.F.R. 177). 

A copy of the ruling or the control number indicated above should be provided with the entry documents filed at the time this merchandise is imported. If you have any questions regarding the ruling, please contact National Import Specialist Paul Huang at paul.huang@cbp.dhs.gov. 
Sincerely,
 (for) Denise Faingar Designated Official Performing the Duties of the Division Director National Commodity Specialist Division