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HQ 003941

October 9, 1996

RR:IA 003941 ch


TARIFF NO.: 8481.90.9060

David Dixon
Cummins Engine Company
Box 3005
Columbus, Indiana 47202-3005

RE: Tariff classification of a thermostat housing.

Dear Mr. Dixon:

This is in response to your letter, dated August 9, 1994, identifying a difference in tariff classification between the United States, Canada and Mexico concerning an in-line diesel engine part identified as a thermostat housing. Pursuant to Article 513(6)(a)(ii) of the North American Free Trade Agreement (NAFTA), the NAFTA Customs Subgroup convened a conference call to discuss this matter on August 7, 1996. In view of the discussion, and upon further consideration of the matter, Customs concludes that the thermostat housing is classified as set forth below.


The housing is part of an assembly which also includes parts identified as a thermostat and a thermostat housing cover. The thermostat is the only moving part of the assembly and consists of a copper bulb, a collar, a hollow cylinder, an inner shaft and an outer shaft. The thermostat is located inside the thermostat housing. The housing cover creates a passage from the assembly to the radiator.

In operation, engine coolant flows from a water manifold and enters the thermostat housing through a port sealed by a trapezoid shaped gasket. In cold operation, the thermostat is closed and the coolant passes through the complete assembly to a water transfer tube, which carries the coolant to the water pump to be circulated back into the engine. As the engine heats, the heated coolant contacts the copper bulb at the top of the thermostat. As a result, fluid inside the bulb expands, causing the inner shaft to extend. This action moves the cylinder into its open position. In this position, the cylinder blocks the passage of coolant to the water pump and opens the passage leading to the radiator.


What is the proper tariff classification for the thermostat housing?


Heading 84.81 provides in part for valves for pipes, boiler shells, tanks, vats or the like, including thermostatically controlled valves. Subheading 8481.90 encompasses parts of thermostatically controlled valves.

The Explanatory Note to heading 84.81, at pages 1430-1431, states in pertinent part that:

This heading covers taps, cocks, valves and similar appliances, used on or in pipes, tanks, vats or the like to regulate flow (for supply, discharge, etc.), of fluids (liquid, viscous or gaseous), or, in certain cases, of solids (e.g., sand). The heading also includes such devices designed to regulate the pressure or the flow velocity of a liquid or a gas.

The appliances regulate the flow by opening or closing an aperture (e.g., gate, disc, ball, plug, needle or diaphragm). They may be operated by hand (by means of a key, wheel, press button, etc.), or by a motor, solenoid, clock movement, etc., or by an automatic device such as a spring, counterweight, float lever, thermostatic element or pressure capsule.

Taps, valves, etc., incorporating such mechanisms or devices remain classified in this heading. This applies, for example, to a valve equipped with a thermostatic element (double-leaf, capsule, bulb, etc.). The heading also covers valves, etc., connected to a thermostatic element by means of, for instance a capillary tube.

(Emphasis supplied).

The thermostat, thermostat housing cover and thermostat housing together comprise a complete valve. The thermostat housing and thermostat housing cover act as the body of the valve which directs the flow of the coolant. The thermostat acts both as a thermostatic element and as a sealing element which opens and shuts a passageway.

In view of the foregoing, the thermostat housing is classifiable in subheading 8481.90.9060 as part of a valve, specifically a valve body.


The thermostat housing is classifiable under subheading 8481.90.9060, Harmonized Tariff of the United States, which provides for parts of valves: other, other: valve bodies. The applicable rate of duty is 2.2 percent ad valorem.


John Durant, Director
Tariff Classification Appeals Division

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