Sliding Vane, centrifugal, and gear pumps are three of the most commonly used pumps for fluid handling, all of which have different purposes and best areas of application. It can sometimes be difficult to choose the one that meets your exact requirement; however, understanding the difference between the three pumping technologies and their working principles will help you make an informed decision. In this article, we’ll cover everything you need to know about these pumps in detail:

Sliding Vane Pumps

A sliding vane pump is a positive displacement pump that consists of blades or vanes that slide in and out of slots in the pump rotor, eccentrically supported in the cam to form a crescent shaped cavity. This cavity traps a certain amount of fluid and forces it into the discharge pipe with each rotation. What goes in is exactly what comes out. No more, no less. These pumps provide a constant flow of fluid at a given speed, and can overcome pressure differences. They are also referred to as rotary vane or constant-volume pumps.

Centrifugal Pump

Centrifugal Pumps are one of the most commonly used pump types in the world. It consists of an impeller, which rotates and creates a centrifugal force that imparts Kinetic energy to the fluid, inducing a flow from a low level to a high level. These pumps are widely used within mining, manufacturing, and agricultural industries due to their large volume handling capacity, small size, user-friendliness, and easy maintenance features.

Gear Pumps

A positive displacement gear pump uses the meshing of two or more rotating gears to form a liquid seal with the casing, which creates a vacuum at the inlet and moves the fluid to the outlet. These pumps are mainly used because of their flow-rate & volume controlling capability. If the pressure within the system remains constant, these pumps can provide more or less fixed fluid flow rate.

Benefits and Drawbacks

Now that we understand the principles of operation & differences for each type of pump, let us go through the benefits and drawbacks associated with each technology:

Sliding Vane Pumps

Pros:

• Highly efficient
• Capability to manage thin/less viscous fluid effectively
• Self-priming.
• Operates at a stable flow rate, thereby ideal to use for motoring
• Limited capacity with high - pressure requirements

Cons:

• Fluid delivery is pulsating in nature
• Not suitable for liquid with solid contents
• Not suitable for highly viscous fluid.
• Cannot close the discharge valve
• Requires safety valve at discharge to prevent mechanical failure

Centrifugal Pumps

Pros:

• Zero chance of leakage unless casing is broken.
• Lower rate of pump deterioration.
• It functions with minimum noise.
• Magnetic coupling will break under heavy load thus saving the motor.
• Gap between the motor & pump will restrict the entry of fluid.

Cons:

• Coupling might slip in case of a sudden heavy load
• If the pumping liquid contains any iron particles, will be collected on the impeller due to magnetic drive, which may leads to clog the pump.

Gear Pumps

Pros:

• Can handle high density or viscosity
• Self-priming.
• Highly Efficient
• Easy to Use and Maintain
• Very controllable