Submersible pumps are generally chosen over end-drive centrifugal pumps when the suction lift is greater than about 7 m, depending on atmospheric pressure. Because submersible pumps are encapsulated they can be fully submerged in water. In addition, they can be used underground to pump between sumps as well as to a collection pit, where a larger pump can transfer water to another level or to surface.
Why submersibles?
Their ease of mobility makes submersibles a popular choice for dewatering as well as pumping sludge and slurry. Once a pump has emptied a sump, for example, it can be quickly relocated to service another requirement elsewhere – raising its overall equipment effectiveness and value to the business.
Submersible pumps are electrically powered – such as the Grindex range, for which Integrated Pump Technology is the official distributor for the SADC region of Africa. This allows ease of installation, a smaller footprint and low maintenance requirements. Grindex pumps are particularly well known for their ‘plug-and-pump’ reliability. Users appreciate being able to take a ‘set and forget’ approach to these pumps.
An important factor behind the popularity of submersibles is their continual technological improvement – constantly raising their efficiency and reliability. Where required, efficiency innovations can include the inclusion of variable frequency drives (VFDs), which automatically regulate the speed of the pump. Non-clog impellers have become standard in these pumps, further boosting their reliability and up-time.
The Grindex range offers additional features such as an air valve, to allow air cooling during extended periods of dry running. Another Grindex innovation is its SMART electronic surveillance system, which controls phase rotation, phase loss and overheating. This SMART unit trips the pump when necessary to prevent wear or damage, minimising maintenance and repair costs.