Balance Vane Pump

It works on the principle of sliding vanes in which pressure at inlet and outlet is balanced with the help of the two pressure quadrants oppose each other.


In balanced vane pumps, the casing is elliptical in shape. The center of the rotor and elliptical casing is the same, and no offset is used. For equilibrium, two inlets and two outlets are provided, due to which no pressure difference is created between the inlet and the outlet port.

Balance Vane Pump
  • Two inlets are present on opposite sides of each other, and two outlets are present on opposite sides of each other. Due to this type of arrangement of inlets & outlets, equal and opposite thrust is balanced, and therefore no side thrust is experienced by the rotor shaft.
  • It consists of a circular rotor with vane slots is concentrically positioned with the axis of an elliptical cam ring.
  • Elliptical cam ring helps to create two inlet and two outlet chambers such that the two pressure quadrants oppose each other and the two inlet chambers are directly opposite to one another.
  • The pressure at inlet and outlet of the pump is balanced therefore the forces acting on the shaft are fully balanced and side loading of the shaft is eliminated completely.

What is Balance Vane Pump – Principle, Construction, Working


  • Working is similar to unbalanced vane pump. Due to elliptical cam ring, the radius of vanes is not constant and changes volume accordingly.
  • During rotation of rotor with slots, the vanes are forced out due to centrifugal force and in constant with the inner surface of the elliptical Cam ring.
  • The pressure at the inlet chamber is less than atmospheric pressure which helps to suck the oil to the inlet suction ports of the pump.
  • The oil from inlet port is moved to forward direction with rotating vanes and carried to the outlet port where its volume decreases.
  • These type of pumps are constant volume or fixed displacement pumps.
  • They can work up to 175 bar pressure. They are relatively quite and having simple construction.


  • Head, Casing – cast iron, ductile iron, steel, brass, plastic, and stainless steel
  • Vane – carbon graphite
  • End plates – carbon graphite
  • Shaft seal – component mechanical seals, industry-standard cartridge mechanical seals, and magnetically driven pumps.

Advantages and Disadvantages of Balance Vane Pump


  • Self-priming, strong, and provide continuous delivery at a fixed speed.
  • Volumetric and overall efficiencies are high.
  • Low internal leakage
  • Balanced vane pump bearing eliminates side loads, and therefore higher operating pressures can be used.
  • Compact design
  • Do not require a check valve.
  • Low noise
  • High efficiency


  • Low operating speed
  • Relief valves are required to protect the pumps in the event of a sudden stop of delivery.
  • It is unsuitable for high viscosity liquids at high pressures.
  • low pressure
  • The manufacturing cost is higher
  • They are not suitable for abrasive liquids.

What is Balance Vane Pump – Principle, Construction, Working


  • Aviation Services – Fuel Transfer
  • Auto Industry – Fuel, Lube, Refrigeration Cooling
  • Transfer of LPG
  • LPG cylinder filling


  • What is the advantage of a balanced Vane Pump?
    It is self-priming, strong, and provide continuous delivery at a fixed speed.
  • How does a balanced vane pump work?
    Pumping chambers are formed between succeeding vanes, carrying oil from the inlet to the outlet. A partial vacuum is created at the inlet as the space between vanes increases. The oil is squeezed out at the outlet as the pumping chamber’s size decreases. Balanced design vane pumps all are fixed displacement.
  • Which type of cam ring is used in balanced vane pumps?
    A balanced vane pump is a very versatile design that has found widespread use in both industrial and mobile applications. The rotor and vanes are contained within a double eccentric cam ring and there are two inlet segments and two outlet segments during each revolution.
  • What is the pressure of balanced vane pump?
    They can work up to 175 bar pressure.
  • What is the difference between balanced vane pump and unbalanced vane pump ?
    Due to the pressure difference in the inlet and outlet port, this vane pump is called an unbalanced vane pump. In balanced vane pumps, there is no side thrust on the rotor shaft.

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By Aditya

Hi, I’m Aditya Sharma, a professional blogger from Gurgaon, India and I launched this blog called aadityacademy on July 2021. is a mechanical Project-oriented platform run by Aditya sharma and I got the motivation to start aadityacademy blog after seeing less technical education information available on google.

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