When you need to remove groundwater, lower a water table, or otherwise remove fluid from the soil, you'll need a dewatering pump. Frequently used for construction and mining, dewatering pumps can remove a large amount of water from one area and take it somewhere where it does no harm. There are three main types: centrifugal, diaphragm, and progressive cavity.

While centrifugal pumps utilize a spilling impeller to create pressure and diaphragm pumps use a rubber membrane to create suction, progressive cavity pumps use a helical screw housed within a cylindrical chamber to move fluids. They're sometimes known as helical screw or eccentric screw pumps, and they offer several advantages that make them ideal for certain applications.

Here are just four reasons you might want to invest in a progressive cavity dewatering pump. 

1. Offers Self-Priming

When you use a centrifugal dewatering pump, you'll need to fill it through the priming port every time it's used, but this isn't necessary with progressive cavity pumps since they offer self-priming capabilities. They cannot be run dry for too long, but self-priming does remove a step whenever you use your pump to help save time and labour. If the pump will be used frequently, this can make a real difference.

2. Handles Viscous Fluids and Solids

Dewatering pumps often need to handle more than just water. That water is seldom going to be pure – contaminants may increase its viscosity, and it's common for suspended solids to be sucked up at the same time. Progressive cavity pumps can deal with such issues. Added viscosity does not lead to mechanical inefficiency, and the flow will remain the same regardless of viscosity. Additionally, the lack of disturbance means suspended solids won't cause damage or premature wear.

3. Offers Variable Flow Rates

When you require a varied flow, a progressive cavity dewatering pump is ideal. This is because you get a precise flow for each revolution of the pump, so you can regulate flow quickly and easily by simply changing the speed. This makes progressive cavity pumps particularly well-suited for use with many of the latest pump speed controllers, including variable frequency drives (VFDs).

4. Provides Efficient Performance

Finally, it's worth keeping efficiency in mind. Progressive cavity pumps offer relatively good efficiency, so they often consume less energy than other types of dewatering pumps. That's going to help keep operating costs under control and reduce your environmental impact, so it's a factor well worth considering if your dewatering pump will be in frequent use.