Application for Further Review of Protest Nos. 4601-17-101789; Classification of Anode and Cathode Components of a Solid Oxide Fuell Cell Machine ATTN Dirik J. Lolkus, Supervisory Import Specialist

H288213 June 22, 2026 OT:RR:CTF:EMAIN H288213 JER CATEGORY: Classification TARIFF NO.: 8503.00.95 Center Director, Electronics C.E.E. U.S. Customs and Border Protection 301 E. Ocean Blvd. Long Beach, CA 90802 RE: Application for Further Review of Protest Nos. 4601-17-101789; Classification of Anode and Cathode Components of a Solid Oxide Fuell Cell Machine ATTN: Dirik J. Lolkus, Supervisory Import Specialist Dear Center Director: This letter is in reference to the Application for Further Review (“AFR”) of Protest No. 4601-17-101789, timely filed on February 9, 2017 on behalf of Bloom Energy, Corporation (hereinafter, “protestant” or “Bloom Energy”), regarding the tariff classification of anode and cathode component parts under the Harmonized Tariff Schedule of the United States (“HTSUS”). The AFR was forwarded to this office for consideration. Our decision is set forth below.1 FACTS: Protest No. 4601-17-101789 is designated as the lead protest, which concerns fourteen entries of component parts used in the construction of a fuel cell electrical generator machine. The merchandise was entered between February 28, 2016, and April 25, 2016, and was liquidated between January 13, 2017, and March 10, 2017, under heading 8543, HTSUS. Specifically, the U.S. Customs & Border Protection (“CBP”) liquidated the subject merchandise as entered under subheading 8543.90.88, HTSUS, which provides for, “Electrical machines and apparatus, having individual functions, not specified or included elsewhere in this chapter; parts thereof: Parts: Other: Other: Other.” 1 This letter corrects typos relating to the protest number in a letter previously sent to the Center, dated June 18, 2026. 2 Bloom Energy manufactures “Energy Servers” which are used as power generation systems based on solid oxide fuel cell technology. The subject anode and cathode assemblies are components of a fuel cell machine referred to as a Solid Oxide Fuel Cell Hot Box (the completed manufacture of which will be completed post-importation). Bloom Energy states that fuel cell machines are electrochemical devices which convert chemical energy into electrical energy. According to protestant, fuel cell machines work on hydrogen H2 or gases containing hydrogen such as natural gas (CH4) for their operation. An electrochemical reaction converts fuel and air into electricity without combustion. They consist of an electrolyte, an anode, a cathode and interconnects. In the case of solid oxide fuel cells, the electrolyte is a solid ceramic material. The anode and cathode are made from special inks that coat the electrolyte. According to protestant, a Solid Oxide Fuel Cell Hot Box is a high temperature fuel cell machine that works with natural gas (CH4) as the fuel. Air at high temperature enters the cathode side of the fuel cell and hot fuel mixed with steam (which forms a reformed fuel i.e., H2 and CO) on the anode side. Next, a chemical reaction begins in the fuel cell. As the reformed fuel crosses the anode, it attracts oxygen ions from the cathode. The oxygen ions combine with the reformed fuel to produce electricity, water, and small amounts of carbon dioxide. The water gets recycled to produce the steam needed to reform the fuel. The process also generates the heat required by the fuel cell. The exhaust gases are made up of a mixture of spent fuel, steam and CO2 on the Anode and air on the cathode. The exhaust gases are all initially at high temperature (>800C). The heat energy available in these streams needs to be recovered to enhance the overall efficiency of the system and to avoid releasing hot gases into the atmosphere. Post-importation, the subject anode and cathode assemblies will be connected to other components such as a fuel rail assembly to form a complete Solid Oxide Fuel Cell Hot Box (“SOFC Hot Box”). The imported merchandise does not include the fuel cell components required for the complete Solid Oxide Fuel Cell Hot Box to function. Specifically, the imported structure does not include the fuel rail assembly (i.e., fuel cells, stacked to form columns over a manifold); nor does it include the current collector, an electric braze assembly, ceramic channel and ceramic insulation, or a voltage probe. However, these non-imported components were discussed and illustrated in the diagrams, flow discussion and product descriptions provided by protestant to illustrate and explain how the subject merchandise functions in conjunction with these parts. In its submission, protestant provided diagrams depicting the anatomy of the Solid Oxide Fuel Cell Hot Box, a flow chart of the fuel, air and exhaust through the SOFC along with the manner in which fuel passes through the fuel cell stacks/column (i.e., the fuel rail assembly). Fuel Rail Assembly The Bloom Energy Fuel Rail Assembly (where the electricity is generated) is not a part of the imported merchandise but will be joined with the subject merchandise post-importation to form a completed SOFC Hot Box. The “Fuel Rail Assembly” consists of fuel cell stacks.2 2 A single fuel cell consists of a membrane electrode assembly (“MEA”) and two flow-field plates delivering about 0.5 and 1V voltage (too low for most applications). Just like batteries, individual cells are stacked to achieve a higher voltage and power. This assembly of cells is called a fuel cell stack, or just a stack. Fuel Cell Store. https://www.fuelcellstore.com/fuel-cell-stacks; A fuel cell stack consists of a multitude of single cells stacked up so 3 Protestant states that multiple fuel cell stacks are stacked on top of each other forming a column (eight columns in total). The columns are installed around the central cylinder of the hot box forming a complete fuel rail. A fuel rail is a manifold which distributes the fuel to the fuel cell stacks/column. Anode Heat Exchanger – Anode Flow Structure The imported parts which make up the subject anode side heat exchanger assembly, described collectively as the Air Flow Structure include the following: Part Number 104644 Assembly (“ASSY”), Fuel Rail Stack Prep (“F.R. Stack Prep”), GERONIMO; Part No. 107373 ASSY, Stack Prep,2.4; Part No. 109855 ASSY, F.R. Stack Prep, S5.0; Part No. 109892 ASSY, F.R. Stack Prep, GERONIMO, HB 2.4 and Part No. 666666 ASSY, F.R. Stack Prep ,YUMA, Orange Gas Reformer. The anode Air Flow Structure (“AFS”) is an assembly in the center of the fuel cell system and is one of the heat exchangers. It also supports other assemblies in the fuel cell system. The AFS structure is largely composed of nickel alloys that are welded and/or brazed together. Protestant describes the Anode Heat Exchange/Air Flow Structure assembly’s operation as follows: Fuel (liquid natural gas) enters the Solid Oxide Fuel Cell Hot Box at the top of the hot box on the anode side (“Anode In”). The new fuel comes in and flows down to the middle top of the AFS, then flows down through the center of the AFS. At the top of the heat exchange fins the fuel flows over to the heat exchange fins surrounding the AFS. As this new fuel flows down through the heat exchanger fins, it is heated up by the exhausted fuel which passes on the other side of the fins. Then, this new fuel is routed inside of the fins it just travelled through and goes nearly to the top of the fins. It then flows down through the very center of the AFS – going through the Orange Gas Reformer (“OGRE”). According to protestant, pure natural gas is CH4, however, “real natural gas” has some gas molecules with “extra” carbon atoms, such as C2H4. The OGRE removes these “extra” carbon atoms from the fuel. The new (reformed) fuel is then heated and moves to the bottom of the AFS where it goes to each of the eight fuel-in fuel rails, one for each column. There are also eight fuel-out fuel rails for the exhausted fuel, one for each column. This passing of the fuel through the column creates electricity, heat, and other byproducts. The exhausted fuel exits the column, moves to the exhaust fuel rail and goes down the exhaust fuel rail. This exhaust fuel is then routed to the perimeter of the AFS, and this exhaust fuel moves up the AFS heat exchanger heating the incoming fuel and exits out of the AFS at the top (“Anode Out”). Cathode Heat Exchanger – Unishell Assembly The parts which make up the subject cathode side heat exchanger assembly, described collectively as the Unishell Assembly, include the following: Part No. 121109 ASSY, UNISHELL, YUMA; Part No. 127600 ASSY, UNISHELL, CATALINA, Downgage, EXT SG, IN 625. The Unishell Assembly’s parts function as cathode heat exchangers, with a single fin design made of Inconel and cylinders also made of Inconel. The Cathode Heat Exchanger also serves as the outer enclosure of the central section of the fuel cell system – it encloses the that the cathode of one cell is electrically connected to the anode of the adjacent cell. Fuel Cell Stack, Science Direct.Com https://www.sciencedirect.com/topics/engineering/fuel-cell-stack. 4 portions of the fuel cell which generates the electricity. The Cathode Heat Exchanger is an outer and inner cylinder of nickel alloy sheet metal, with a finned heat exchanger sandwiched in between both layers. This is installed over the completed central assembly which the AFS, discussed above, is the central portion. The Cathode Heat Exchanger structure is largely composed of nickel alloys that are welded and/or brazed together. Protestant describes the “Cathode Heat Exchange - Air Flow” operation as follows: Cathode exhaust from the fuel cells passes through a portion of the Anode Flow Structure, AFS. This Cathode exhaust mixes with a percentage of anode exhaust stream and flows through a catalyst that converts CO to CO2. This exhaust, the Anode Tailgas Oxidizer (“ATO”), exhaust then feeds into the Cathode Heat Exchanger. The Cathode Heat Exchanger structure removes the ATO exhaust from the fuel cell system, exiting the Cathode Out (via two pipes at the top of the Cathode Heat Exchanger). The ATO exhaust stream passes through a finned heat exchanger which is the outside wall of the Cathode Heat Exchanger. This flow cools the ATO exhaust stream before expelling it into a ventilation module. Heat from the ATO exhaust stream is exchanged with incoming ambient air, flowing on the other side of the finned heat exchanger of the Cathode Heat Exchanger. This pre-heated air is then delivered to the cathode side of the fuel cells in the system. The fresh air coming into the fuel cell begins at the top right of the SOFC (“Cathode In”). This fresh air enters through the Top Hat. The top hat sits above the AFS, and some of the heat from the AFS is exchanged with the fresh air. This fresh air then moves down into the Cathode Heat Exchanger outer wall where the fresh air is further heated by the hot used air which is being exhausted on the other side of the heat exchanger. This hot fresh air is then released into the area around the outside of the AFS where it enters the fuel cell columns. The fresh air reacts in the fuel cell and becomes exhaust air. This exhaust air is now in the outside of the AFS where it heats up the incoming fuel. The exhaust air moves to the bottom, and out to the outside wall of the Cathode Heat Exchanger where it travels up and out the top of the Cathode Heat Exchanger. Top Hat The Top Hat parts include: Part No. 111303 ASSY, Top Hat, Tangent Flow, CATALINA, S5; Part No. 125160 ASSY, Diffuser, Top Hat ASSY, YUMA, described collectively as the “Top Hat Tangent Flow Assembly” and as a “Top Hat Diffuser Assembly,” These parts function together as a guide for incoming air from the blower to the hot box. They are plenums to divert the air within the hot box in a uniform manner. The top hat is where the fresh air enters the fuel cell. The structure of the Top Hat, which sits atop the AFS, encourages the fresh air to pick up heat from the AFS as the air travels to the Cathode Heat Exchanger. The Top Hat is made of stainless-steel sheet metal and stainless-steel fittings. Flange Rings For the Flange Rings; Part No. 115928 SM, Flange Ring, ATO, and Part No. 115929 SM, Flange Ring, Anode ASSY, described collectively as “Flange Rings.” These parts are perforated stainless steel plates used to mount the heat exchangers in the assembly. They are for structural 5 support only so that the assembly can be bolted in place. These flange rings are annulus shaped rings which are put on top of the base of the Top Hats. The flared base of the Top Hat is made of thin stainless steel. The Flange Ring is used to reinforce where the Top Hat is joined to the Cathode Heat Exchanger (Unishell) to ensure a good seal between the Top Hat and the Cathode Heat Exchanger. These rings are made of stainless steel. Other Post-Entry Component Parts According to the information provided, there are additional components that will be installed post-entry with the subject merchandise in addition to the (unimported) Fuel Rail Assembly. These additional components include, a current collector, an electric braze assembly, ceramic channel and ceramic insulation, and a voltage probe assembly. ISSUE: Whether the imported goods were properly classified in heading as parts of a fuel cell in heading 8543, HTSUS, or whether they should be classified as parts under heading 8503, HTSUS, or as heat exchangers under heading 8419, HTSUS. LAW AND ANALYSIS: We note that this matter is protestable under 19 U.S.C. § 1514(a)(2) as a decision regarding the rate and amount of duties chargeable. The protest was timely filed on February 9, 2017, within 180 days of liquidation. (Miscellaneous Trade and Technical Corrections Act of 2004, Pub. L. 108-429, § 2103(2)(B)(ii), (iii) (codified as amended at 19 U.S.C. § 1514(c)(3) (2006)). Further Review of Protest No. 46019-17-101789 is properly accorded to Protestant pursuant to 19 C.F.R. § 174.24(b) because the decision against which the protest was filed is alleged to be inconsistent with matters previously ruled upon by the Commissioner of Customs or his designee or by the Customs courts. Classification under the HTSUS is in accordance with the General Rules of Interpretation (GRIs). GRI 1 provides that the classification of goods is determined according to the terms of the headings of the tariff schedule and any relative section or chapter notes. In the event goods cannot be classified solely on the basis of GRI 1, and if the headings and legal notes do not otherwise require, the remaining GRIs 2 through 6 will then be applied in order. The 2017 HTSUS headings at issue are: 8419 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. * * * 8503 Parts suitable for use solely or principally with the machines of headings 85013 or 8502. * * * 3 Heading 8501, HTSUS, provides for “[e]lectric motors and generators (excluding generating sets).” 6 8543 Electrical machines and apparatus, having individual functions, not specified or included elsewhere in this chapter; parts thereof. Note 2 to Section XVI, HTSUS, in relevant part, provides: Subject to note 1 to this section, note 1 to chapter 84 and to note 1 to chapter 85, parts of machines (not being parts of the articles of heading 8484, 8544, 8545, 8546 or 8547) are to be classified according to the following rules: (a) Parts which are goods included in any of the headings of chapter 84 or 85 (other than headings 8409, 8431, 8448, 8466, 8473, 8487, 8503, 8522, 8529, 8538 and 8548) are in all cases to be classified in their respective headings. (b) Other parts, if suitable for use solely or principally with a particular kind of machine, or with a number of machines of the same heading (including a machine of heading 8479 or 8543) are to be classified with the machines of that kind or in heading 8409, 8431, 8448, 8466, 8473, 8503, 8522, 8529 or 8538 as appropriate. However, parts which are equally suitable for use principally with the goods of headings 8517 and 8525 to 8528 are to be classified in heading 8517, and parts which are suitable for use solely or principally with the goods of heading 8524 are to be classified in heading 8529…. Note 2 to Chapter 84, HTSUS, in relevant part, provides: Subject to the operation of note 3 to section XVI, a machine or appliance which answers to a description in one or more of the headings 8401 to 8424 and at the same time to a description in one or more of the headings 8425 to 8480 is to be classified under the appropriate heading of the former group or under heading 84.86, as the case may be, and not the latter group. (A) Heading 84.19 does not, however, cover: * * * (v) Machinery or plant, designed for mechanical operation, in which a change of temperature, even if necessary, is subsidiary…. In understanding the language of the HTSUS, the Harmonized Commodity Description and Coding System Explanatory Notes (ENs) may be utilized. The ENs, though not dispositive or legally binding, provide commentary on the scope of each heading of the HTSUS, and are the official interpretation of the Harmonized System at the international level. See T.D. 89-80, 54 Fed. Reg. 35127, 35128 (August 23, 1989). The ENs to heading 8419, HTSUS, state, in pertinent part, that: With these exceptions, the heading covers machinery and plant designed to submit materials (solid, liquid or gaseous) to a heating or cooling process in order to cause a simple change of temperature, or to cause a transformation of the materials resulting principally from the temperature change….But the heading excludes machinery and plant in which the heating or cooling, even if essential, is merely a secondary function designed to facilitate the main mechanical function of the machine or plant..[.] * * * The heading includes a very wide range of machinery and plant of the types described below. * * * (I) HEATING OR COOLING PLANT AND MACHINERY 7 This group covers plant of general use in many industries for the simple treatment of materials by heating, boiling, cooking, concentration, evaporation, cooling, etc. They include: * * * (B) Heat exchange units in which a hot fluid (hot gas, steam or hot liquid) and a cold fluid are made to traverse parallel paths, but usually in opposite directions, separated by thin metal walls in such a manner that the one fluid is cooled and the other heated. These units are usually of the three following types, viz., in the form of: (i) Concentric tube systems: one fluid flows in the annular interval, the other in the central tube. (ii) A tubular system for the one fluid, enclosed in a chamber through which flows the other fluid. of baffles plates. or (iii) Two parallel series of interconnected narrow chambers formed of baffle plates… Protestant Asserts that the anode heat exchanger assembly or Anode Flow Structure (“AFS”) and the cathode heat exchanger assembly (also referred to as the “Unishell Assembly”) should be classified as heat exchangers in heading 8419, HTSUS. Protestant argues that the essential character of the AFS structure, which includes the anode, is that of a heat exchanger. In particular, protestant asserts that because a heat exchange occurs as the anode exhaust stream and the incoming natural gas pass each other on opposite sides of the finned heat exchanger, this activity constitutes a heat exchange for purposes of the ENs of heading 8419, HTSUS. Protestant not