The Importantance Of Dewatering
Dewatering plays a pivotal role construction, mining, tunnelling, lift irrigation, dam construction, dry docks, storm water drains industries etc. It is the process of safe removal of excess water by dewatering can prevent hazards like mudslides, unstable foundations, and equipment failure due to bogging. This also ensures your worksite is in a condition ready for excavation, foundation preparation and cement footing pours.
The advantage of this technique rests mostly in its ability to cut cost. Additionally, it is suitable for removing water from shallow excavations approximately 6.5 m in soils that are stratified. This can also be seen as a disadvantage especially when the excavation is deeper than 7.0 meters.
There are four main dewatering methods used in construction:
- Wellpoint.
- Educator Wells.
- Sump Pumping.
- Deep Wellpoint.
Three categories of Dewatering :
- Submersible Pumps:
These pumps are designed to be either fully or partially submerged in water and can move both liquids and small abrasives, like sand. Instead of pulling the water to the surface, a submersible pump will push the liquid via a discharge pipe to the surface. Using a pump that is submerged or at the same level as the water has several advantages including.
- They take up minimal space and can run off the on-site electrical supply
- Does not need priming as the pump is already submerged in water
- Submersible pumps are very energy efficient
- Noise is kept to a minimum as the pump is underwater
- Centrifugal Pumps:
Centrifugal dewatering pumps are designed to be positioned on the sump or dam wall using a long suction hose and strainer lowered into the water. For dewatering, these are generally self-priming, so they do not require priming prior to use. Once the pump is primed, the water is pumped through the outlet pipe into a dam, pond, tank, or other location.
- Well Point Pumps:
A well-point pump is a positive displacement pump and is self-priming. These pumps are predominantly used to lower the water table on construction sites so construction can take place without any groundwater flooding the site. They can pump a mixture of air and water without the need for a separate self-priming system.
Steps to consider while selecting Dewatering Pumps :
As we mentioned earlier, choosing the wrong size pump can cause a range of issues. Before selecting a dewatering pump consider the following.
- Static Head Pressure:
You will need to establish the static head (also known as the pressure head) to ensure the pump can produce enough pressure to create the required vertical flow of water.
- Flow rate:
It’s important to choose a pump that can produce the flow rate needed to remove the water. Aside from the pump, take care in selecting the length of the suction pipeline.
- Temperature and Altitude:
Fluid temperature and the altitude at which the pump needs to operate can dramatically affect the suction capability of the pump. Talk to your supplier about where you’ll be using the pump to ensure you make the right choice.
If you’re in need of a dewatering pump, As an original equipment manufacturer (OEM) Sovereign pumping solutions , we ensure all our products are built to the highest standard and can perform in the toughest conditions, both in India and overseas.
