Centrifugal Pump Applications

The centrifugal pump is designed for high efficiency and doesn’t consume a lot of power. However, it can’t be used for everything. There are some applications in which it is the best choice, but many in which it isn’t appropriate. It is important to know the difference. Here are some facts about centrifugal pumps and some of the industries in which they are used.

How a Centrifugal Pump Works

A centrifugal pump has a simple design: an impeller spinning inside of a casing. This converts rotational energy into centrifugal force by forcing liquid into the centre of the impeller and propelling it out of the impeller channel and then into the volute chamber. A portion of that force is converted into pressure because there is less space in the casing.

Centrifugal pumps provide, as mentioned above, high efficiency with low power usage. In some larger buildings, multiple centrifugal pumps are used in series, making the low power usage crucial. Because their design is so simple, centrifugal pumps require minimal maintenance and last longer than many other varieties.

Centrifugal Pump Applications - Pump Solutions Australasia

Centrifugal pumps are used for many applications, including water supply for large buildings, as supply pumps and as booster pumps. They are also used in the dairy, food, beverage and light chemical industries. They are efficient for pumping slurries and sewage due to their design. They are also used for heating and cooling systems and in fire protection systems.

At Pump Solutions Australasia, we import centrifugal pumps from the best manufacturers in the world, including Grundfos, Speck Pumpen, Lowara, Calpeda and Gorman Rupp.

Call Pump Solutions Australasia Today

The best way to know for sure whether you need a centrifugal pump or a different variety is to talk to someone who knows pumps like the back of their hand. At Pump Solutions Australasia, we have the most knowledgeable and professional customer service personnel in the business.

To learn more or to find out which pump is the best one for your application, call Pump Services Australasia today: 1300 793 418.

Factors in Choosing the Right Centrifugal Pump

When you are choosing a centrifugal pump, it is important to match it to the application and pumping system both mechanically and hydraulically. If you install a pump that doesn’t match, it can result in ongoing performance issues until the imbalance is corrected.

Hydraulic Factors

Matching a centrifugal pump to a system means making sure to consider some important factors. These include the flow rate, the system design, the amount of resistance in the system and the system curve.

System Design

The pump has to be the right size for the system. Deviation may force the pump to operate outside its design parameters. This can cause excessive noise, cavitation, vibration or circulation issues.

Flow Rate

The head created by the pump is the main determinant of the flow rate in the pumping system.

System Resistance

System resistance head counters both the friction head and the static head in the system.

Duty Point

When the system resistance head is equal to the head created by the pump, it is called the duty point. When selecting a centrifugal pump, it is crucial to identify the accurate duty point.

Choosing the Right Centrifugal Pump

Net Positive Suction Head (NPSH) Made Available

The NPSH is determined by subtracting the vapour head of the fluid being pumped from the total absolute head at the point of pump suction. It is important to know the NPSH available (NPSHA) when selecting a centrifugal pump for any given application. If the NPSH available isn’t greater than the NPSH required (NPSHR) with an extra margin for safety, the pump will be at heightened risk for cavitation.

Suction Lift

In clean water systems that only transport cold water, a measurement called suction lift can be used to simplify calculations. In this case, it is also recommended that a safety margin is added in.

Matching the Requirements to the Right Pump

Once you have determined the total dynamic head, the flow rate and the NPSH or the suction lift, you can choose a pump which is appropriate for your system. The specifications can be presented with a constant speed with different impeller diameters corresponding with different head quantity curves. It can also be presented with a constant impeller diameter and varying speeds.

Either set of parameters will indicate power use, pump efficiency and the NPSH or suction lift required for the flow range of the pump. You can then determine the input power kW and speed (RPM) using the total head, required flow and suction lift from the performance curves.

Hydraulic Selection

Ideally, your system would be best served with a pump that has an NPSHA that is greater than the NPSHR by a reasonable margin while running at best efficiency point (BEP). The volute and impeller are operating as designed and the flow of the pump is smooth. Bearing loading, energy dissipation, vibration and shock are at a minimum and the pump should operate for a long time with no downtime.

Sadly, “ideally” isn’t often possible for a number of reasons. There is only a finite number of available pumps. Pump manufacturers would have to custom design individual pumps for individual systems. This is not feasible, practically or economically. Consequently, pumps are selected from units that are commercially available.

Specific speeds can be limited. For example, a duty point with a low flow rate and high head can exceed the limits of impeller design, causing the pump to operate near minimum continuous flow. A limited NPSHA can limit pumping speeds and running speeds.

Because duty requirements can vary to great extents, it can be impossible to find an ideal selection. For some operations, the ideal pump may be too complicated or cost prohibitive. Ultimately, choosing the right centrifugal pump can be a tradeoff between reliability, efficiency and cost.

How Big is the Compromise?

If the duty point rate is from 50-110% of the best efficiency flow rate, the pump is normally considered “acceptable.” If the BEP can’t be matched perfectly, a centrifugal pump whose operation is to the left of the BEP is preferable to one that exceeds the BEP.

We Can Take Care of it For You

Our customer service is the best in the business and we also have access to the manufacturers. If you are having trouble selecting a centrifugal pump, call Pump Solutions Australasia today. We don’t just import pumps, we provide solutions: 1300 793 418.

Grundfos Leads the Way with Energy Saving Pumps

Sometimes, what happens thousands of miles away in Vancouver, British Columbia, can have an impact on water pumps in Perth, Australia. British Columbia is as cold as Australia is hot. They are mountainous while Australia is mostly shoreline, coastal cities and towns, and bushland, with the occasional rolling hill.

Pump

The common ground: energy conservation and sustainability. Vancouver is a coastal city that has numerous high-rise buildings. In the city, condos, hotels, and office buildings are usually very tall. With all of these high-rise buildings comes a big problem: maintaining water pressure on the top floors.

Nobody wants to rent in a building that can’t provide adequate water pressure to all of its occupants. In any building that is rented or leased, high occupancy makes the difference between making money or losing one’s shirt. Recently, the Sheraton Wall Centre decided to ask Grundfos for help.

The Sheraton Wall Centre occupies twin towers which are each 49 storeys tall. As many Vancouver area businesses do, the Sheraton is dedicated to being “green,” or doing its best to conserve energy and promote sustainability. When management discovered that they were expending excess energy to provide adequate water pressure, they called Grundfos in for a pump audit.

While some companies would have taken advantage of this and ripped out the old pumps to install all their own product, Grundfos Canada engineer Sherezad Shafiq was able to present a much more cost-effective solution that was almost totally non-disruptive of water service in the hotel.

After analysing the amount of water and the energy it took to get it there, the Grundfos solution was to simply install the MCP BoosterpaQ, which has three CR pumps with variable speed, along with a controller package. This produced the correct water pressure while saving energy.

Instead of a major install, all they did was put in the three new pumps on each building alongside of those already in use. When the pumps were put into action between 3am and 6am, there was almost no disruption of water service for the guests, and there were no complaints.

We can import virtually all Grundfos products. Call 1300 922 973 to find out how Grundfos can bring your high-rise energy costs down.

What Kind of Pump Do You Need for Your Irrigation System

For most irrigation systems, the best water pump will either be a submersible pump or a centrifugal pump. Often, you will find pumps on the market that are called “irrigation pumps.” Sometimes, they will be sufficient, but they will often be cheap pumps that barely get the job done under the best of conditions.

IrrigationConsequently, we recommend that you do your homework and work with your supplier to make sure you get the pump that is right for your system. We recommend that you design your irrigation system first, and then figure out how much water you are going to move and what pump you need. This can save you a lot of time and effort.

For lighter irrigation, a plain, submersible pump, similar to the one you would use to clear a flooded basement, will be fine. Submersible pumps are totally submerged underwater, including the motor. The pump and motor are combined into a single unit that is in a waterproof casing. They can even be used in a well or a stream.

Submersible pumps are very efficient, because they push water instead of pulling it. The main caveat here is that most submersible pumps need a sleeve that forces water to flow over the surface of the motor, and keeps it from overheating. This pump has to be run totally underwater. If it is running while dry, it will burn the motor out and damage the pump.

A centrifugal pump uses centrifugal force to move water. It uses an impeller, similar to an old fashioned water wheel, to propel water through the casing, also called the housing or chamber. Centrifugal pumps have to be primed before they will move water. Self priming centrifugal pumps are easily primed; all you do is put water in the intake pipe and turn the pump on.

The most common centrifugal pump is an end-suction centrifugal pump. The pump is round, with a suction inlet on the front and an exit outlet on the top. The motor can be long or close-coupled to the pump, and are normally quite efficient

So, what is the best way to choose a pump? Call 1300 922 973 today and let our experienced professionals make the call.

A Simple Guide to Pumps: Part 1

We get a lot of questions about pumps. What kind of pump is right for the job? What is the difference between kinds of pumps? How do water pumps work? We’re going to give you a simple guide to some of the pumps we offer throughout Australia, and hope we can make your choices easier. If it doesn’t work, you can always feel free to call us or email us; we will be happy to recommend the right pump for the right job.

Vacuum Pumps

A vacuum pump works just like a shop-vac. It removes air to create a vacuum. This causes lower pressure in the space where the air was removed, and allows the higher-pressure air to rush in and fill the space created when the air was removed. The most popular vacuum pump is a positive displacement pump. Vacuum pumps are used more for applications that don’t involve water, but are sometimes used in sewage systems.

Centrifugal Pumps

A centrifugal pump moves water by converting rotational kinetic energy into hydro dynamics energy. The energy comes from a motor, and water enters an impeller, where it is accelerated to move outward through the pump to either a diffuser or a volute chamber, where it then leaves the pump. Centrifugal pumps are best used for water, but are often used for sewage, chemicals, slurries etc.

Rotary Vane Pumps

A rotary vane pump is classified as a positive-displacement pump. It has vanes which are mounted to a rotor inside of a cavity. The simple type has a circular rotor which rotates inside of a circular cavity. The centres are slightly offset, causing what is known as eccentricity. To make a long story short, they are often used for holding wood or other materials down on CNC Routers in the furniture industry.

Double Diaphragm Pumps

A double diaphragm pump, also known as an AODD, is classified as a positive displacement pump that uses two diaphragms made of thermoplastic, Teflon, or rubber, which work with a reciprocating action. They can be up to 97% efficient, are self-priming, and can handle viscous fluids. They can also handle solids and corrosive liquids. Most uses for this pump are industrial, but they are also used on the filters for fish tanks. Another interesting use is artificial hearts.