U.S. Customs and Border Protection · CROSS Database · 1 HTS code referenced
Primary HTS Code
8419.89.9085
$224.7M monthly imports
Compare All →
Ruling Age
30 years
Data compiled from CBP CROSS Rulings, Census Bureau Trade Data · As of 2026-05-03 · Updates monthly
The tariff classification of an ammonia oxidation converter unit from France.
NY 811455 July 07, 1995 CLA-2-84:S:N:N1:104 811455 CATEGORY: Classification TARIFF NO.: 8419.89.9085 Mr. Gary T. Cooke Du Pont Import Operations Duttons Mill Business Park 380 Turner Way Aston, Pennsylvania 19014 RE: The tariff classification of an ammonia oxidation converter unit from France. Dear Mr. Cooke: In your letter dated June 5, 1995 on behalf of E. I. du Pont de Nemours and Company of Wilmington, Delaware you requested a tariff classification ruling. The purpose of the ammonia oxidation converter unit is to produce nitrous oxides. The unit is composed of two converters, each of which is divided into an upper and lower section. The upper is an ammonia burner consisting mainly of a gas inlet nozzle, elliptical head, shell, collar flange, an internal set of gas distribution baffles, a catalytic baskets bed, fixed and removable heat shields. The lower is a vertical boiler (forced circulation and water tube type) consisting of the boiler shell, 4 internal boxes, shell line coil, vaporizing bundle (2 inlet and 2 outlet headers), superheater and tubular beam assembly. The entire unit will be imported in one shipment. Superheated ammonia vapor and air are mixed together prior to entering the converter. As the hot gas mixture flows across the catalyst bed, a highly exothermic reaction occurs which generates a tremendous amount of heat. This reaction converts the ammonia and air into nitrogen oxide and water. As the reacted gas passes into the lower section of the converter, it flows around circulating water filled tubes which extract heat from the reaction thus cooling off the gas. This removal of heat is critical because it reduces the gas temperature to an acceptable level for operation of the downstream equipment. As the tubes absorb heat, steam is generated. The steam is then used to preheat the incoming ammonia and air. The applicable subheading for the ammonia oxidation converter unit will be 8419.89.9085, Harmonized Tariff Schedule of the United States (HTS), which provides for machinery, plant or laboratory equipment, whether or not electrically heated, for the treatment of materials by a process involving a change of temperature such as heating, ... or cooling, other than machinery or plant of a kind used for domestic purposes; other. The rate of duty will be 4.2 percent. This ruling is being issued under the provisions of Section 177 of the Customs Regulations (19 C.F.R. 177). A copy of this ruling letter should be attached to the entry documents filed at the time this merchandise is imported. If the documents have been filed without a copy, this ruling should be brought to the attention of the Customs officer handling the transaction. Sincerely, Jean F. Maguire Area Director New York Seaport