How to choose the right water pump?

This guide is going to help you to choose the right water pump step by step. 

Water pump types

At first, you need to know water pumps can be classified according to many different dimensions. If it was classified according to the use, it includes booster pump, transfer pump, sewage pump, metering pump, and so on. If it was classified by its material, it includes cast iron pump, cast-aluminum pump, stainless steel pump, engineering plastic pump, and so on. If it was classified by drive power, it includes gasoline water pump, diesel water pump, electric AC water pump, electric DC water pump, and etc. If according to the pump’s applications, there will be too many types and very hard to be counted.

There are many other dimensions, such as single-stage or multi-stage, vertical or horizontal, unable one by one cited. But the most commonly used classification method is based on the pump’s principle. In this article, we mainly use this method to classify the water pumps. Based on this classification method, the pumps currently on the market mainly include the following types:

Centrifugal water pump

Centrifugal water pump uses the centrifugal force generated by the impeller to transfer the fluid. The centrifugal force typically comes from an engine or electric motor. Centrifugal pump can serve long-time continuous operation and has a long lifespan. It is the most widely used type of water pump.

Diaphragm water pump

The diaphragm water pump is another common type of water pump. It relies on the reciprocating action of a membrane to change the working chamber volume to transfer the fluid. Compare to the centrifugal pump, a diaphragm pump could generate extremely high pressure. But it often has a small flow rate, a short lifespan, and a loud noise.

Peristaltic pump

The peristaltic pump uses a rotor with a number of “rollers” to squeeze a flexible tube to transfer fluid. It is often used in the pharmaceutical or chemical industry to get a constant accurate flow rate.

The above three principles of the pumps contained the vast majority of pumps on the market. You may know other principles pumps, such as jet pump, gear pump, plunger pump, but that is not in our discussion today.

The development trend of water pump

High-efficiency and energy-saving are undoubtedly important trends in the future development of the water pump. So the fuel-based water pumps will be replaced, the electric water pump will be more and more popular. Based on the reasons for safety and technological progress, AC water pumps will be more replaced by low-voltage DC water pumps. The size of the pump will get smaller and more compact. Smaller and more portable, but the same performance.

Common mistakes when choosing a water pump

1. Could the performance meet your needs? Almost all water pumps have two important parameters: head and flow rate. They are usually marked on the label of a pump like this: “Max head 15M, Max flow 1800LPH”. But please be noted, it means this pump can achieve the max head of 15 meters OR can achieve the max flow of 1800 liters per hour. It doesn’t mean this pump can achieve 1800 liters per hour at 15 meters height.
2. Certification considers your real cost! The unit price is only part of your cost. You also need to consider the pump’s lifespan, maintenance cost, replacement cost. If the pump needs a continuous operation, you will need to consider the cost of the electricity. It is usually more expensive than the unit price of a pump. Furthermore, if you are going to use the pump in your products (equipment) and sell them to your customers, the reputation of your business will be your biggest cost. Therefore, a simple choice by unit price is the second common mistake people often make.

Select the right pump then!

After figuring out the above problems, the process of choosing a pump becomes clearly, but still difficult. To keep it simpler, next we will narrow down the problem as “how to choose an electric centrifugal water pump”. Because the centrifugal pump can meet most of your requirements. For other types of pumps, you can refer these steps.

1. Ensure the pump performance can meet your needs: How high must the water be pumped and what is the flow rate requirement at this height? For example, your answer should like that: “we would like it to be 600 LPH at 5 meters height”. Then check the pump performance curve and to see if it meets your requirements.
2. Confirm the water pump’s operation voltage. (Or power supplier)
3. Make sure the size of the pump is suitable: easy to be installed, the inlet and outlet are easy to be connected to the pipe of your system.
4. What kind of liquid? Is it corrosive?
5. What are the liquid temperature and the ambient temperature?
6. What is your expected lifespan of the pump?
7. Does the pump need to operate continuously? and how long each time?
8. Does the pump need the self-priming function? Be note, most small centrifugal pumps don’t have this feature.
9. Do you have any requirements for the pump material? Need food grade?
10. Does the pump need extra features? Such as time control, speed feedback & control, protection functions, and etc.
11. Does the pump need to work submersible? Any requirements for the Noise?

You should give priority to some of the above steps based on your actual needs. You may also have other special requirements, if you are not sure whether the pump can meet all of your requirements, the best way is to contact the pump manufacturer’s technicians, let them help you to select the right water pump.