Jargon Buster

If this is your first water pump purchase or you are new to the industry, you'll see that there are lots of new terms and descriptions to get to grips with. Words such as 'submersible' or 'multistage' may look a little daunting in that they won't be familiar to you.

But don't worry, we want to help you become familiar with some of these terms so that you can be equipped with the necessary knowledge and understanding to make your water pump purchase. Please refer to our simple Jargon Buster below to become familiar with the terms and definitions.

Jargon Buster
image Pump Impeller

A Water Pump Impeller is similar in concept to the propellor of a boat, but rather move the boat, it moves the water flowing at it. A motor controls the speed of the impeller producing enough force to push the water out of the pump and to the destination (house taps, garden etc).

Pump impellers spin at a high rate and use centrigual force to energise the water out of the pump. A single impeller pump is known as a single stage pump but you can have many impellers built into a single pump - this is called a multistage pump. Multistage pumps generate more water pressure, output and flow.

Pump impellers can be mounted horizontally (horizontal stage pump) or vertically (vertical stage pump) according to the pump design.

image Jet Pump

A Jet Pump can draw or 'suck' water from a water source such as a shallow well, bore or underground tank. They are mounted above the water source and draw the water up through suction. Because suction is involved, atmospheric pressure is what's really doing the work. Think of the system as a long straw. As you suck on the straw, you create a vacuum in the straw above the water. Once the vacuum is there, the weight of the air, or atmospheric pressure, pushes the water up the straw. Consequently, the height that you can lift the water with a jet pump relates to the weight of the air. While air pressure varies with elevation, it's common to limit working operation depth of a jet pump; this varies according to the make and model.

How they work

Jet pumps create suction in a rather novel way. The pump is powered by an electric motor that drives an impeller, or centrifugal pump. The impeller moves water, called drive water, from the well through a narrow orifice, or jet, mounted in the housing in front of the impeller. This constriction at the jet causes the speed of the moving water to increase, much like the nozzle on a garden hose. As the water leaves the jet, a partial vacuum is created that sucks additional water from the well. Directly behind the jet is a Venturi tube that increases in diameter. Its function is to slow down the water and increase the pressure. The pumped water–new water that's drawn from the well by the suction at the jet–then combines with the drive water to discharge into the plumbing system at high pressure.

Because jet pumps use water to draw water, they generally need to be primed–filled with water–before they'll work. To keep water in the pump and plumbing system from flowing back down into the well, a 1-way check valve is installed in the feed line to the pump.

image Self priming Pumps

A water pump draws water from its source (such as a tank or well), passes it through its internal pipes and chambers, and forces it out at high pressure using one or more fast spinning 'impellers' (similar to propellors on a boat).

Most if not all water pumps need to be filled with water for the pump to operate. If there is only air inside the pump and no water, no pressure can be utilised. A pump therefore must first be primed; that is, air or gases expelled from the suction and impeller area, and replaced with liquid.

A Self-priming Pump is designed to insure that a sufficient quantity of liquid to reprime is always retained in the priming chamber, making it completely self operational and functional.

image Multistage Pump

A centrifugal pump containing two or more impellers is called a Multistage Centrifugal Pump. The impellers may be mounted on the same shaft or on different shafts.

For higher pressures at the outlet impellers can be connected in series.

For higher flow output impellers can be connected in parallel.

image Pressure Controller

So you have just turned on the tap in your bathroom to take a shower. How does the water pump situated in your garden next to the water tank know when the pipes serving the house are rapidly emptying of water and it's time to switch itself on to draw some more water from the water tank? Well that's the job of the Pressure Controller.

The Pressure Controller is an electronic device that sits on top of the water pump. It continually monitors the water pressure at the exit pipe of the water pump; if the water pressure drops to a certain pressure, the pressure controller knows that water is being drawn by a source (such as a water tap) and immediately turns the pump on to keep the water pressure and flow constant while the source is being used. When the source stops using the water, the pressure increases in the pipes. When the pressure in the water pump reaches a certain pressure, the pressure controller switches off the water pump.

image Pressure Tank

If you have ever had the misfortune of discovering a small leak either from a dripping tap or water pipe or you often use water sparingly (such as flushing the toilet or filling the kitchen sink) or you are in a situation where your pump supplies devices that evaporate water (such as air conditioning units), a Pressure Tank could be just what you need. Pressure Tanks are like mini water storage tanks that are mounted on top of or next to the water pump. They come in all shapes and sizes and provide just enough water for short demands. Storing enough residual water for small applications, they lessen the number of water pump starts thereby saving electricity and the lifecycle of the water pump. They can also come with pressure controllers that can be adjusted to switch on and off the water pump when required.

image Submersible Pump
If you have a deep well, bore or underground tank or you need a pump to run quietly at any water source, then a Submersible Pumpis what you are looking for. This type of water pump is installed inside the tank, bore or well and sits happily underneath the water line operating just like a jet jump.

Submersible pumps are made from water resistant materials and so do not rust. They also do not affect the taste or quality of drinking water. Coming in all shapes, capacities and sizes, submersible pumps can be used for a variety of applications and the added benefit of them being quiet in operation makes them a popular choice in domestic and commercial environments.

image Frequency Drive

Now here is where it gets clever! What if you could control the energy used by your pump everytime you turn on one or more taps in your home? Well you can with Frequency Drive technology. It basically works like this. You turn on 1 tap, the pump starts but uses no more than the energy needed to support that 1 tap. Turn on a second, and the pump will spin faster, a 3rd, faster still and so-on - it's the ultimate pump economy at your fingertips and not only this, it greatly reduces the wear and tear on the pump motor and all its working parts.

Frequency Drive Contollers save money, energy and maintenance.

image Centrifugal pump

A Centrifugal Pump uses centrifugal force to push incoming water delivered to the pump casing, to the outside world. Inside the pump, a motor turns a shaft a specified velocity. An impeller fixed to the center of the shaft turns in a rotational manner to correspond to the speed of the shaft. As water passes into the pump chamber the impeller spreads it to the outside (using centrifugal force). This creates pressure inside the pump casing - enough to force the water out of the pump to pipes that take it to the taps in the house or garden.