Submersible Pump Vs Surface Pump: Best One For Your Borehole

SUBMERSIBLE PUMP VS SURFACE PUMP

The problem of knowing the best pump to install in your borehole is not common in most areas. However, when the wrong choice is made in another area it becomes a big problem.

There are two types of pumps you can use in your borehole, it is either you install a surface pump mounted just above the bore or you install a submersible pump known as a sumo. A combination of the two may be necessary for building with heights or large sizes of water tanks that need to be filled with water within a short time.

Understanding the working principle of each pump, the advantages and disadvantages of each pump, and overall knowledge of both pumps will assist you in making any purchasing decision.

WORKING PRINCIPLE OF A SUMO (submersible pump)

Submersible pumps use in borehole applications have little difference from the normal submersible pumps used in industrial applications and other purposes. A submersible pump is a pump that can be submerged inside the water.

The pump usually has a stainless steel case and is well sealed against water penetration into its interior parts. The cable supplying current to it is usually insulated with layers of thick and flexible polymer products.

When submerged inside water, the pump sucks water directly from its head and discharges the water through the outlet port at the back or side of the pump. The submersible pump can either be a single-stage, double-stage, or multiple-stage submersible pump. The number of stages of the submersible determines the pressure output of the water and the head (height) that the pump could deliver water.

Submersible pumps are of different types, however, the ones use for boreholes in buildings are popularly known as sump pumps.  A sump pump is usually long in length with a small diameter. Some can be as small as 300mm in diameter while the length could measure up to 1000mm or more. 

The suction impeller is located at the end part of the pump while the discharge is located at the top side of the pump alongside the cable that supplies current to it. When submerged, the suction side faces downward while the discharge side faces upwards.

ADVANTAGES AND DISADVANTAGES OF SUMO

Sumo pumps have lots of advantages and disadvantages. Below are some of its advantages:

Sumo pump delivers water without priming

It does not make noise while operating

It comes in various sizes you can choose any size for your borehole

It has stainless steel casing making it impossible to corrode inside the borehole throughout its lifespan

It ensures water is delivered quickly once it receives current

Some of the sumo can still pump water even when there is a low voltage

It has a longer life span than a surface pump

It is very applicable in boreholes with high depth or Head, in other words, deep boreholes.

However, below are some of its disadvantages:

If submerged too deep it could pump out sands

It is difficult to remove when there is a need for repair as compared to the surface pump

It is costlier than surface pumps

WORKING PRINCIPLE OF A SURFACE PUMP

The surface pump used in the borehole is a simple centrifugal pump that has its suction in the axial position and its discharge in the radial position. The pump has priming ports in the case of difficulty in suction. This type of pump is very applicable in boreholes with low depth, in other words, boreholes with a few meters depth below the ground surface.

The surface pump is usually installed just on the ground surface of the borehole, a PVC pipe is inserted into the borehole and fixed at the suction port of the pump in its axial position while another PVC pipe is fixed on the pump radial port where it delivers the water it sucks from the borehole. The pump operates with a simple installation setup.

ADVANTAGES AND DISADVANTAGES OF SURFACE PUMP

Below are the advantages of the surface pump:

It has an easier installation procedure

It is easy to dismantle during repair

It is cheaper than the Sumo pump

The sound it makes will help you to know if it is working or not

Below are some of its disadvantages:

The sound can be a source of disturbance

Sometimes water leakages at the pipes end fixed on the pump could soak the ground with water

It is not good for a borehole that is very deep

Sometimes the pump can fail to suck the water from the borehole if it is primed or the suction pipe is made to shake a little.

COMPARISON BETWEEN SUMO PUMP AND THE SURFACE PUMP

By comparison, the two seem to have their best area of application hence no one can be placed superior to another. However, the sumo pump seems to have a wider area of application than the surface pump because it can function effectively in any borehole no matter the depth of the borehole. This advantage made sumo a better choice for those that want to ensure there is no technical challenge when pumping water.

Nevertheless, if you can afford the two pumps, mounting the two will not only ensure water is delivered effectively, it will also prolong the service life of both pumps because of the following reasons:

The sumo can use less power to pump the up to the ground surface while the surface pump will use less power to send the water to the water tank. Hence, the two pumps will work efficiently.

The application of the two pumps will increase the water flow pressure. This means that it will take a shorter time to fill up the water tanks.

The shorter time of filling the water tanks helps to prevent the rise in the temperature of the pumps’ electric motors, thereby helping to prolong the lifespan.