What Are Vane Pumps?
A vane pump is a self-priming positive displacement pump providing constant flow at varying pressures. Operation is via a motor connected to a gearbox as typically the maximum rpm is 900. The pump is fitted with a relief valve to prevent the pump from building to a pressure which may damage the pump.
The pump head contains a slotted rotor which contain vanes. The vanes create segmented chambers within the pump head, partitioning the pump head between the rotor and outer casing which enable the vane pump to be self-priming as the chambers operate similar to valves. They are manufactured in a variety of materials, enabling them to be compatible with multiple fluids. They can be manufactured from Bronze, Stainless Steel, PVDF, Carbon or Aluminium as shown below:
The pump head is circular for the most part but has a flat portion as the vanes move in and out of the main rotor as they rotate within the casing. The vanes push outwards within the casing due to the centrifugal force when the pump is in operation with forces exerting outwards keeping the vanes tight against the casing making them self compensate for wear.
When the vanes reach the outlet of the pump the casing is flatter and tighter against the rotor causing the vane to be pushed into the rotor and the fluid to expel through the outlet of the pump.
View our vane pump animation
Vane pumps are reversible which makes them an excellent choice for stripping and unloading tanks.
Then can be operated in reverse to then fill tanks or load vehicles as the pump can be operated in both directions. Typically vane pumps are fitted with either a single mechanical seal, double mechanical seal with barrier fluid, or gland packing.
They are typically used for viscous fluids which are lubricating such as oils, petroleum’s, diesel, animal oils/blood, and fuel oil. They can also handle non-lubricating fluids such as solvents due to their being no metal to metal contact. Vane pumps self-compensate for wear meaning they can maintain peak performance without loss of flowrate.
Vane pump Advantages and Disadvantages can be summarized as follows:
Rotary Vane Pump Advantages and Disadvantages | |
Advantages | Disadvantages |
Can handle viscous fluids up to 10,000cst | Pump requires a gearbox meaning pump can be larger / heavier than other designs and can also be less efficient due to mechanical losses through gearbox. Belt Driven designs can eliminate gear box
|
ATEX rated for handling of flammable liquids | Can not handle solids or abrasives |
Heating chamber allows solidifying liquids to be kept at low viscosity and prevent solidification within the pump | Limited viscosity handling compared to other positive displacement pumps - maximum of 10,000cst |
High Suction lift capability and can Self Prime up to 8M | |
Reversible meaning pump can be used to load and unload tankers, but also ensure product is fully recovered from hoses. | |
Flow rate is largely unaffected should back pressure or pressure losses change. | |
Vane Pumps self-compensate for wear. As vane tips wear they extend further out of the rotor ensuring efficiency is maintained. Other pump types lose efficiency as they wear | |
Multiple sealing options from Single Mechanical Seal, double mechanical seal and gland packing ensures suitability for a wide range of liquids. | |
Vane pumps vs Gear pumps vs Liquid Ring Vs Centrifugal pump
VP = Vane Pumps
Vane Pumps Vs Gear Pumps | Vane Pumps Vs Liquid Ring Pumps | Vane Pumps Vs Centrifugal Pumps |
VP are more efficient | VP can handle higher viscosities | VP are more efficient with fluids above 200cst |
VP do not have metal to metal contact allowing pump to prime from dry but also strip containers, and handle non lubricating liquids | VP do not have metal to metal contact allowing pump to prime from dry but also strip containers, and handle non lubricating liquids | VP flow is maintained if viscosity is increased, whereas centrifugal pumps experience a drop in flow once outside designed duty point. |
Gear pumps can have bearing or bushings in contact with fluid which can cause bearing lubrication issues with low lubricating fluids | Liquid ring pumps do not have as many sealing options. | VP are self-priming by design. |
Gear pumps are more precise for dosing or metering | VP typically have a lower NPSH requirement | VP do not have metal to metal contact allowing pump to prime from dry but also strip containers, and handle non lubricating liquids |
Gear pumps can have timing gears significantly increasing cost and meaning maintenance is more difficult | VP self compensate for wear. | |
VP have lower vibrations | Centrifugal pumps can have impeller design changed to handle solids, or abrasives. | |
VP have limited high viscosity handling (10,000cst vs gear of 55,000 cst) |
There are a range of Symbols that can be used to represent Vane Pumps in Process and Instrumentation Drawings - learn more.
FAQS
The mechanical seal requires lubrication and cooling while the pump is operating. Without the presence of fluid, the mechanical seal will overheat and crack, and this may cause the pump to leak and fluid to enter the motor. There is also the possibility that the motor will burn out. Our advice is to ensure that the pump always has access to fluid while running, the vessel or sump on the inlet side of the pump must never run out of fluid while the pump is active.
Level sensors or a float switch can be installed in the fluid chamber ensuring that the pump is turned off in the event there is no fluid. Another way of protecting the pump is to fit a dry running device, this will turn the pump off if it detects that no fluid is entering the pump. If you think that dry running is inevitable, then please speak to us and we will try to select a more suitable pump for your application.
