Q&A

What is an End Suction Centrifugal Pump:

An End Suction Centrifugal pump is the most common pump type. Its simple design has been tried and tested for centuries! The basic principal of the centrifugal pump is fluid flows into the inlet of the pump where it enters the eye of the impeller. The impeller is driven & rotated by mechanical means such as an electric motor or engine etc. The rotation of the impeller creates centrifugal force which directs the fluid along the impeller vane blades and pushes the fluid to the outer tip of the impeller vane where it enters the pump volute casing. The volute is shaped in a “snail shell” type shape which directs the fluid around the volute casing, which is then separated by a “cutwater” or “breakwater”. The Cutwater / Breakwater splits the water between the discharge and the recirculating fluid in the volute casing.

There are several different kinds of centrifugal pumps with different impeller styles, trims, shapes etc.

 

What is a Horizontal Multistage Pump:

 A horizontal multistage pump is a centrifugal pump containing two or more impellers. The impellers may be mounted on the same shaft or on different shafts, but for the majority if pumps they are on the same shaft. The fluid flows into the inlet of the pump casing where it flows into the eye of the impeller. The impeller is driven & rotated by mechanical means such as an electric motor or engine etc. The rotation of the impeller creates centrifugal force which directs the fluid along the impeller vane and pushes the fluid to the outer tip of the impeller vane where it enters the stage diffuser. The diffusers are a type of cutwater which direct the fluid into the suction eye of the next impeller. This process continues until the fluid has passed through each impeller stage. The fluid is then directed out the pump casing through a final diffuser and into the pump discharge.

Each stage that the fluid passes through increases the discharge pressure.

Multistage pumps are used when higher pressures are required which single stage pumps of the same size are unable to attain.

 

What is a Jet Pump:

A jet pump is a single stage centrifugal pump with either a built in jet ejector or an ejector kit on the suction line. This enables the pump to lift fluid from below the pump ie. Self-prime. There are two basic types of Jet pumps, Shallow Well Jet Pumps, and Deep Well Jet Pumps.

Shallow Well Jet Pumps are able to lift water up to ±7.5mtr, while Deep Well jet pumps are able to lift water from depths of up ±50mtr

The pump is fitted with a Jet Ejector or Ejector Kit which is made up of a nozzle & venturi. The venturi nozzle receives water at high pressure. At the tip of the high pressure nozzle, there is a low pressure water area. This discharge of high pressure high velocity into the low the pressure water creates suction which enables the pump to lift water.

 

What is a Vertical Multistage Pump:

 A vertical multistage pump is a centrifugal pump containing two or more impellers. The impellers may be mounted on the same shaft or on different shafts, but for the majority if pumps they are on the same shaft. The fluid flows into the inlet of the pump casing where it flows into the eye of the impeller. The impeller is driven & rotated by mechanical means such as an electric motor or engine etc. The rotation of the impeller creates centrifugal force which directs the fluid along the impeller vane and pushes the fluid to the outer tip of the impeller vane where it enters the stage diffuser. The diffusers are a type of cutwater which direct the fluid into the suction eye of the next impeller. This process continues until the fluid has passed through each impeller stage. The fluid is then directed out the pump casing through a final diffuser and into the pump discharge.

Each stage that the fluid passes through increases the discharge pressure.

Multistage pumps are used when higher pressures are required which single stage pumps of the same size are unable to attain.

 

What is the difference between a Peripheral Vane Pump and a Standard Centrifugal Pump:

The main difference between a regenerative turbine pump and a centrifugal pump is in the impeller. A standard centrifugal impeller has curved vanes that extend from the centre to the edge of the impeller. The regenerative turbine impeller has rows of vanes on each side of the impellers rim. On the suction side liquid is gathered by the impellers vanes, after making only one revolution in the annular channel, the fluid has a high-velocity that sends the liquid out the discharge. Liquid entering a centrifugal pumps impeller can pass between the vanes only once. Energy is added to the liquid as it travels from the centre of the impeller to the rim. In a regenerative turbine pump liquid recirculates between the impellers vanes. This helical action carries the liquid forward, energy is added to the liquid in a number of impulses by the impellers vanes as it travels from suction to discharge as a liquid builds pressure.

For low flow high head applications regenerative turbine pumps offer better efficiency than centrifugal pumps and can develop several times the discharge pressure of a centrifugal pump having an equally sized impeller.

The regenerative turbine impeller can pump fluid with up to 40% entrained gases without damage from cavitation or any performance loss. Centrifugal pumps are not designed to handle gas in a liquid, gas in a centrifugal pump can create a significant loss in performance causing fluctuating flow, discharge pressure, and unnecessary wear and vibration of the centrifugal pumps internal components. This makes a regenerative turbine pump a great solution with cavitation is a concern.