Rotor bushings run in the pumped liquid or are isolated by seals. Vane pumps usually operate at 1,000 rpm, but also run at 1,750 rpm. The pumps work well with low-viscosity liquids that easily fill the cavities and provide good suction characteristics. Speeds must be reduced dramatically for high-viscosity applications to load the area underneath the vanes. This type of pump has better dry priming capability than other PD pumps.
Vane pumps can run dry, but are subject to vane wear.
Abrasive applications require the proper selection of vane material and seals. Vane pumps have fixed end clearances on both sides of the rotor and vanes similar to external gear pumps. Once wear occurs, this clearance cannot be adjusted, but some manufacturers supply replaceable or reversible end plates. Casing liners are a low-cost way of restoring pump performance as wear occurs. Unlike lobe pumps, vane pumps cannot handle solids.