The key distinction is functional design: valves under SITC 74720 are engineered to control fluid power within hydraulic or pneumatic circuits — managing direction, flow rate, or pressure in a power-transmission context — rather than simply isolating or throttling flow in a pipeline. Documentation from the manufacturer confirming the intended circuit application supports correct classification.

Beyond standard commercial invoices and packing lists, importers should obtain technical datasheets specifying operating pressure range, fluid medium, and body material. These details are often requested during CBP review and are essential for confirming the correct tariff subheading.