Pros and Cons of Sliding Vane Pumps – Part 5 of The Best Metering Pump
Magnetic-drive vane pumps (also known as rotary vane or sliding vane pumps) are well known for having few moving parts, which allows greater ease of maintenance, and for their ability to run dry for short periods of time.
Sliding vane pumps create individual chambers in the pump, making them ideal for fluids that are toxic or corrosive, expensive or hard to seal. The sliding vanes adjust themselves according to the flow, providing high levels of pumping performance and low shear rates. In addition, you only need a few simple tools to ensure your sliding vane pump performs optimally.
How Does a Vane Pump Work?
A vane pump uses a rotor with sliding vanes to draw the liquid. Centrifugal force extends the vanes to the outer sleeve. When rotating, the inner face of the vane is exposed to discharge pressure and the outer face of the vane is exposed to inlet pressure. This differential is what provides volumetric efficiency as pressure increases. To provide different flow ranges, you can change the cam sleeve of a vane pump.
Main Uses for Vane Pumps
Sliding vane pumps are able to handle low to moderately viscous fluids, particularly ammonia, solvent, fuel, alcohol and many more. This makes them very useful for the petroleum and gas industries, as well as the automotive industry, where sliding vane pumps are used for engine cooling. The vanes and sleeves used in rotary vane pumps are manufactured from self-lubricating carbon (resin impregnated) which allow it to run dry.
Let’s review the pros and cons of rotary vane pumps in more detail to see why are among the best metering pumps available:
Pros of the Sliding Vane Pump
- Good metering range/turndown (100:1 is most practical)
- Compatible with most chemical (available in a full range of plastics and alloys)
- Excellent chemical containment: Sliding vane pumps cannot leak
- Zero pulsation
- Low maintenance complexity, with few moving parts
- Medium maintenance frequency: Vane life is typically 3-5 years
- Excellent off-gass handling
- Can run dry for periods
- Pumping will not be interrupted
- Good viscosity / shear sensitivity (especially at lower speed for viscous liquids)
Cons of the Sliding Vane Pump:
- Unsuited to slurries and solids
- Poor dry suction lift and only moderate wet suction lift
- Relatively high cost, only competitive above 250 LPH