Submersible centrifugal pumps — where the motor and pump are sealed together for operation underwater — are generally classified as centrifugal pumps under this N.E.S. heading, provided no more specific heading applies. The submersible configuration is a design feature, not a separate classification criterion, though the combined motor-pump assembly may warrant review of whether it is better classified as a pump or as a motor-driven machine.

Material of construction — such as cast iron, stainless steel, or exotic alloys — does not typically change the SITC classification of a centrifugal pump, but it can affect the applicable HTS subheading at the 10-digit level and therefore the duty rate. Pumps with bodies made of materials subject to Section 232 tariffs on steel or aluminum may carry additional duty exposure depending on how CBP treats the finished article.