8481.20.00 - Valves for oleohydraulic or pneumatic transmissions

HTS 8481.20.00 specifically classifies valves designed for use in oleohydraulic (oil-based hydraulic) or pneumatic (air-based) transmission systems. These valves are critical components in machinery and equipment that utilize fluid power to operate, controlling the flow, direction, pressure, and speed of hydraulic fluid or compressed air. Examples include directional control valves, pressure control valves, and flow control valves used in excavators, industrial robots, manufacturing machinery, and automotive systems.

This category is distinguished from its siblings by its specialized application. Unlike 8481.10.00 (pressure-reducing valves) which are solely focused on lowering pressure, or 8481.40.00.00 (safety or relief valves) which are designed to prevent over-pressurization, valves under 8481.20.00 perform a broader range of control functions within a hydraulic or pneumatic circuit. Similarly, it differs from check valves (8481.30) which only permit flow in one direction, and other general appliances or parts (8481.80 and 8481.90) by its specific operational context within fluid power transmissions.

The subcategories within 8481.20.00 further refine this classification. "Hydraulic valves" encompass those specifically designed for oil-based systems, while "Other" covers valves intended for pneumatic applications or those that may serve a dual purpose. This distinction is important for accurately reflecting the medium being controlled and the specific engineering design of the valve.