Side Channel Pump

A side channel pump is best described as a semi-positive displacement pump with their own unique characteristics. Side Channel pumps were invented by Mr Siemen and Mr Hinsch (SIHI) in 1920 so it is a well proven design and hence the name SIHI pump was derived.

What “type of a pump” is a side channel pump?

A side channel pump is neither a Centrifugal pump nor a Positive displacement pump because it lies somewhere in between but it is a rotating pump rather than a reciprocating pump.

How does a side channel pump work?

The working principle behind a side channel pump encompasses an impeller of a specific design which is fully opened with many straight vanes. The main side channel is derived from one of the components in the pump and is situated next to the impeller which has a scalloped recess and the flow takes place through the side channel. The flow takes the form of a spiral through the pump.

The unique characteristics of these pumps are;

  • high head per stage when compared to Centrifugal pumps
  • power curve i.e. the reverse of a Centrifugal pump i.e max. power is @ low or zero flow.

What are the uses and applications of side channel pumps?

One of the primary uses of side channel pumps is for low flow and high head applications. Services where they can be entrained air or gas i.e tanker unloading. These pumps are inherently self-priming if the suction piping is configured correctly. The side channel principle limits the flow to 35m3/hr on the largest hydraulic modules. Other applications include self-priming where a relatively clean liquid is being handled. By using a “combination” pump i.e. with a centrifugal suction impeller, the pump will require an extremely low NPSH which makes it suitable for handling boiling liquids or very volatile liquids i.e. condensate applications.

What are the advantages and disadvantages of using a side channel pump?

The main advantages of using a side channel pump is that the hydraulic sizing can be optimised due to various hydraulic sizes available and the ability to have more than 1 impeller in the pump i.e. multistage pump.

There is also a lower noise level due to the low running speed.

Side channel pumps ability to handle larger quantities of air or gas up to 50% in comparison to a Centrifugal pump where a 5% gas would result in a reduction in performance.

With side channel pumps there is a very low NPSH requirement with a “combination” pump and a steep performance curve which makes pump sizing less critical.

The main disadvantage of the side channel pump is the limited solids handling capability due to the very close internal clearances inside the pump.

What are the various “types” of SIHI pumps which Flexachem supply?

Flexachem is the Irish distributor for SIHI Pumps and spare parts supply a wide range of Flowserve SIHI Pumps from side channel pumps;

  • Single stage side channel pumps
  • Multi stage side channel pumps
  • Horizontal side channel pumps
  • Vertical side channel pumps
  • Submersible side channel pumps
  • Magnetic drive side channel pumps
  • Long coupled side channel pumps
  • closed coupled side channel pumps

These are available in a variety of different materials and are frequently used on chemical applications.

Flexachem also supply a SIHI Supernova range for hot water applications- centrifugal water pump – SIHI Z range of high pressure pumps and for hot oil applications – heat transfer pump.

Magnetic drive pumps are usually derived from mechanically sealless pumps and these are available for side channel pumps and centrifugal pumps in Magnetic drive form.

The SIHI multi stage pump is based on the centrifugal principle and generally the multi stage pump has much wider pressure and coverage limits (up to 450m/hr and 160 bar pressure) compared to the side channel pump which has a limit (up to 35m/hr and 35 bar pressure).

Some of the heritage brands used by Flowserve’s history of SIHI pumps include; SIHI itself, Halberg and Sterling fluid systems.

Contact our Pump Specialist Team:

Phil Soltan (External) – mob: 086 185 3782

Internal Team

Adrian McSweeney – tel: 021 461 7212

Paul-Fox Morris – tel: 021 461 7231

Fiona Foley (Pump & Service Support) – tel: 021 461 7240

Tel: 021 4617 200

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