We recently supplied these self priming pumps for a seawater transfer application. The pumps are constructed from cast iron and fitted with bronze impellers. Pumpsets Ltd unitised the sets in our workshop with fabricated base plates, 4-pole high efficiency electric motors and belt drives with guards.
Due to the relatively low head required for this particular application, the challenge was to select pumps that met the design duty conditions whilst also being able to self prime drawing liquid a significant distance from below the pump centre line.
As is common with many types of self priming centrifugal pump a minimum pump rotational speed is required to enable the pumps to be capable of self priming.
Once all of the air has been expelled from the suction pipe, the pump is primed and works like a normal centrifugal pump
The belt drives are a simple method to adjust pump speed (by differing pulley diameters) to match the design duty closely. Inverters were an option but in order to minimise the electrical control panel costs, in this particular instance belt drives were considered the most economical method to achieve the required design duty and limit the installed motor power.
Submersible pumps were not a preferred option for the customer as he wanted to replace the currently installed submersible pumps and reduce the associated additional costs, hazards and complication of lifting the pumps for service and maintenance in a busy harbour environment.
The pumps and controls are to be housed in a purpose built pump house constructed from materials sympathetic to the existing harbour surroundings.
by Pumpsets Ltd