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Submersible Pumps are one of the main components of Package Pump Stations, as well as being used in isolation for many different applications.

Submersible pumps come in many different shapes and sizes, and thus can be used for a multitude of different applications, ranging from small scale drainage and dewatering to dam and reservoir management.

The principle of all submersible pumps, however large or small, is always the same; the pump comprises two main areas. The Volute (of Hydraulic End), and the Motor Housing.

The Volute is a chamber which is flooded, and contains an impeller which displaces the water around the volute, which then exits via the discharge port by centrifugal force.

The Motor Housing is a sealed chamber in which the motor runs under dry conditions. The motor housing is kept watertight by mechanical seals where the motor shaft passes through to drive the impeller (many submersible pumps use dual mechanical seals). The power cable enters the motor housing via a specially designed entry seal, which is integral to the power cable to prevent water ingress between cable and seal. This entry seal is then bolted to the pump casing with 'o' ring(s) to ensure complete water tightness to IP68.


The impeller is the moving part within the volute. It displaces the pumped medium around the hydraulic end, such that it can discharge under pressure. There are a number of different impeller types found on submersible pumps;
Vortex: This impeller type is used when the pumped medium contains coarse solids and/or fibres. It works by providing a large free passage through the volute so that large solids can pass through the pump without touching the impeller and be carried away by the flow of discharged water. Vortex Impellers are normally used for Sewage / Foulwater Pumping Stations
Single-Channel: These impellers are used when small solids may be present in the pumped medium. They also provide a large free passage, but the solids would pass through a channel through the impeller rather than beneath the impeller as with Vortex. Single-Channel Impellers are normally used for surface water pumping stations.
Screw: Screw Impellers are the type of impeller which are normally used for pumping high viscosity media, such as sludge, mud, and slurry. They are not vaned like Vortex and Channel Impellers, and instead work using the viscosity of the medium. They are extremely effective for this purpose, as the lack of veins means that they do not clog and lose efficiency.
Macerator Impellers Macerator type impellers are a two part impeller; the first stage is a grinder arrangement, designed to vastly reduce the physical size of any solids present in the pumped medium. The second stage is a multi channel impeller: more efficient than vortex or single channel impellers at pumping high heads. These types of impeller are only used, however, where a high head is present, and the flow rate requirement is low. Macerators are intrinsically incapable of pumping large flow rates, and are consequently rarely used on sites other than individual dwellings or small groups of homes.

Other types of impeller are available on request for specialist applications.

Pump Service and Technology UK
The Pumphouse
393 Millfield Lane
St Helens
WA11 9TD

Tel: 01942 276773
Fax: 01942 717997