Which is the correct pump for my sewage system?
An effective sewage system is crucial to the smooth running of any operation, but which pump type do you need to ensure maximum efficiency? With several different options available, we’ve summarised the three main types of sewage pumps to help you in your decision.
Vortex Submersible Pump
The Vortex Impeller creates a revolving mass of water which forms a whirlpool. A whirlpool is a funnel-shaped opening created downward from the water surface. It can be developed by water flowing out of a small opening in the bottom of a basin, in a reservoir or by a pump.
The benefit of a Vortex Impeller over a Channel Impeller is the minimised risk of clogging. They’re also a better choice when the pumped liquid has a high content of sand. The efficiency of a pump with a Vortex Impeller is typically lower than one with a Channel Impeller.
Applications: For sewage & stormwater, particularly when dealing with a high sand content
- Large clear passage
- Gives the greatest solid handling capacity
- Significantly reduces blockages
- Typical flow range available 1 to 500 litre/sec
A Grinder Pump is a centrifugal pump equipped with a grinder system at the pump inlet, which cuts larger particles and fibres into a homogeneous wastewater mass.
As a result, the risk of clogging in the pump and the pipe system is reduced to a minimum. More importantly, a Grinder Pump is ideal for pump systems with smaller pipe diameters, where the flow is typically lower. This is relevant when pumping from remote areas or single houses. This pump type is not suited to pumping media with a high content of sand and they consist of more wearing parts, therefore requiring additional ongoing maintenance and spares.
Applications: For sewage, when there’s a high head application, or small pipework size
- Risk of clogging greatly reduced
- Ideal for small pipe diameters
- Ongoing maintenance needed
- Typical flow range available 0.25 to 20 litre/sec
A Channel Impeller works directly on the pumped liquid with the liquid passing through the impeller itself. It can be described as a closed, semi-open or open impeller.
The impeller can have one or more channels of varying size, allowing for the free passage of impurities up to a particular size. In those with more than one channel, fibrous impurities may get caught on the leading edges of the vane, causing the pump to clog. Liquid with a high sand content will cause problems with clearance, but when specified correctly this pump type can have efficiencies as high as 80-85%.
Applications: Used for sewage and stormwater, particularly for when there is a high flow and a high head application
- Can include several channels of varying size
- Free passage of impurities up to a particular size
- Fibrous impurities may cause clogging
- Efficiencies as high as 80-85%