VI pumps have a closed type impeller with front and rear rings as well as balancing holes, to minimize the axial thrust, and a large eye to meet low NPSH requirements. The pump shaft is fully machined to respect the most restrictive run-out API requirements, labyrinths and deflectors at both bearing housing covers allow maximum protection against dirt and the discharge column mounted with a sliding fit through the sole plate accounts for thermal expansions.

As an option, a full jacketed construction can be added to minimize pump distortions caused by local heating, additional rigid coupling can facilitate mechanical seal maintenance activities, a suction strainer will benefit particularly dirty services, and open impellers can be used for waxy or fibrous solids.