In centrifugal pump design, there are essential components and supplies for centrifugal pumps. Some of these include the actual pump, motor, accessories and auxiliary components. The main parts of centrifugal pumps consist of a stationary component (volute) and a rotating element (impeller). Motors are important components that are available in various horsepower and kilowatt ratings. Likewise, these pumps require different accessories and auxiliary components such as control valves, drains, wear rings and mechanical seals.

Whether you require accessories and supplies for centrifugal industrial pumps, centrifugal water pumps or pumps for different applications, there are vendors that can meet your business needs. When buying supplies for centrifugal pumps, some options you may consider are:

1. Choose the correct horsepower motor for industrial centrifugal pumps.

2. Determine the type of impeller design (closed, open, semi-open or vortex) you need for an application. A closed impeller will require wear rings.

3. Find a centrifugal pump manufacturer or distributor that offers auxiliary components and accessories.

Action Steps
The best contacts and resources to help you get it done

Look at pump curves to select the motor for a centrifugal pump application

It is important to select the correct motor size for a centrifugal pump. Some centrifugal pump manufacturers may provide pump curves for different size products. A pump curve gives the performance characteristics of centrifugal pumps. On these curves, important variables are the total dynamic head, efficiency, brake horsepower, net positive suction head and the capacity. Using these charts, you can select the best motor size for an application. Another factor for the proper selection of motors is the specific gravity of the media pumped.

I recommend: State Supply is a distributor of Bell&Gosset pumps and replacement components that include motors, motor mounts and pump accessories. Centrifugal pumps are available in a variety of horsepower; call or fax for a quote on centrifugal pump prices. Franklin Electric carries end suction centrifugal pumps and replacement parts that include motors. ChemicalProcessing.com provides a good article on motor selection for a centrifugal pump.

Select the right impeller and supplies for centrifugal pumps

Centrifugal pumps can be classified in different ways such as by flow type, suction type and on construction type (opened, closed, etc). The number of stages for a pump depends on the number of impellers. Vortex pump impellers are suitable for string media but are not as efficient as other designs. Semi-open and open have less probability of clogging, while closed impellers, which have sidewalls that enclose the vanes, require wear rings. Wear rings should be replaced when the clearance between the impeller and the casing doubles to avoid vibration problems.

I recommend: Alternate Source Parts offers a variety of centrifugal pump parts like impellers, wear rings, shafts, sleeves and stuffing box covers; part for ANSI and API pumps are also available. Pump Components also carries a wide selection of pump parts including different types of impeller design and wear rings. You can search for components by item description.

Buy accessories for a centrifugal pump

Centrifugal pumps may require mechanical seals, seal kits, bearing assemblies, or different types of valves. Whatever your business need may be, look for suppliers that have good inventories of different types of accessories and supplies for centrifugal pumps. You should compare both prices and products from different vendors before you make a final selection.

I recommend: Go to G&O Thermal Supply for bearing assemblies and seal kits. AB Industrial Equipment offers centrifuge pumps, mechanical seals and valves.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  To keep centrifugal pumps functioning properly, the three main areas to look at are lubrication, alignment and seal replacement. Be sure to see the manufacturer's recommendations as to the kind of lubricant needed for the equipment, and how often to lubricate the pump parts.

When your design requires a centrifugal pump, you need to choose the best design from one of the many centrifugal industrial pumps available on the market. You need to consider what material you are moving and the speed at which the material must be moved. Look in the right place and most likely you'll find a supplier to meets all the needs of the project.

Your bidders need quotes and you need budget numbers, so you'll also have to factor in centrifugal pump prices as well. The centrifugal pump selection specs need to be worked out during the design phase of the project. Review several centrifugal pumps from different centrifugal pump manufacturers so that you get the right pump for your application.

Here are some questions you'll need to answer before selecting a centrifugal pump for your engineering application:

1. What type of material are you moving with the centrifugal pump?
2. What is the volume of material you must move?
3. What kind of centrifugal pumps will keep operation and maintenance costs down?
4. What are your budget constraints and what is the most cost effective choice for the application?
   

Action Steps
The best contacts and resources to help you get it done

Compare centrifugal pumps

Engineering catalogs have what seems to be an endless description of specifications for centrifugal pumps. Finding the one to fit your application is tricky business.

I recommend: Search and compare many suppliers at once by visiting GlobalSpec, which is an engineering catalog library that makes searching for the right part easy. Simply type in your need at the find box, click a category then narrow your search by selecting a needed spec. ThomasNet is another such resource that also allows you to compare suppliers of centrifugal pumps. Their site allows you to narrow your search down to the state the company supplies to as well.

Educate yourself on centrifugal pump design application

When your design project takes you into unfamiliar territory, it's great to get a helping hand. Attending a seminar or taking an online class gives you the tools you need to get the job done right and in a timely manner.

I recommend: John Hopkins University Engineering Program for Professionals offers engineering enrichment classes and graduate programs for those in the mechanical, civil and environmental engineering field to ensure you have a thorough knowledge of centrifugal pump applications. For a more specialized approach, try Boss International's "Pumping Systems Design for Civil Engineers" two-day seminar.

Get the right centrifugal pump for the job

You need the right pump for the job. This sometimes means looking at spec sheets and crunching numbers. That is, unless you can find a tool to help you do the number crunching for you.

I recommend: Try Impeller.net's Pump Selector. They are the online pump magazine with not only a pump selector resource directly on their home page, but also an encyclopedia as well. Grainger is another specialist in centrifugal pumps, with a catalog of hundreds of models.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  Manufacturing facilities sometimes use a centrifugal air pump to move clean air into an area or dirty air out and marine centrifugal pumps are used to pump chemical cargo on and off cargo ships. This is why you must find the pump that is right for your application, because you certainly don't want to pump air with one of the centrifugal water pumps, or sewage sludge with a pump designed to pump air.

Centrifugal pumps are very simple devices designed to move fluids. These pumps work by converting mechanical energy into kinetic energy and then to pressure. These energy conversions occur in the two main pump components, the impeller and the stationary involute. There are three categories used to classify centrifugal pumps based on the type of flow they produce. These are axial flow, mixed flow and radial flow.

Centrifugal pump manufacturers can design products for different applications such as marine, water, low flow irrigation and industrial. There are also different types of products like a self-priming or a vertical centrifugal pump. These versatile pumps are relatively simple in construction, inexpensive and require low maintenance. However, they can be inefficient under certain conditions. For an efficient pumping system, a good centrifugal pump design is very important.

Before selecting centrifugal pumps, you should consider the following:

1. Review factors like fluid flow rate, pump size, head requirements, and pump performance curves to choose energy-efficient centrifugal pumps.

2. Find the right centrifugal pump for an application.

3. Compare products from different centrifugal pump distributors.

Action Steps
The best contacts and resources to help you get it done

Find a centrifugal pump manufacturer that offers good technical information or resources

Knowing centrifugal pumps basics is important to select a proper pump product. Because the impeller component is a main consideration in the design of this type pump, manufacturers can offer pumps with different impeller designs that can perform efficiently under different conditions like high flow rate with low head. A centrifugal pump manufacturer should provide charts and performance curves for different pump models. Before selecting a product, check out the performance curve, which shows the efficiency, capacity and the total head of the pump model.

I recommend: Sethco Division offers corrosion-resistant vertical centrifugal pumps designed to pump acids, caustics and seawater. You can get performance curves, drawings and specifications for these pumps. At Myers, you can find different types of this product. Download the product manual to see the performance data. For more information on how to select energy-efficient centrifugal pumps, go to Pump Systems Matter, an educational initiative created by the Hydraulic Institute.

Know the type of centrifugal pumps you require for an application

Different applications/media require different types of pumps. You can find some distributors that offer only marine centrifugal pumps. Other manufacturers may carry wider selections of products like centrifugal industrial pumps, centrifugal water pumps and priming centrifugal pumps. For a marine or industrial application, the pump may be NiAl bronze, which is a good material choice because of its corrosion resistance properties.

I recommend: Ampco Pumps offers marine and industrial pumps in stainless steel and nickel aluminum bronze. This vendor also provides good information on products, a reference sheet on NiAl bronze and pump performance curves. For Goulds centrifugal water pumps, go to American Tank. Different types of water pumps offered by this vendor are multi-stage vertical and end-suction pumps. Gorman-Rupp carries standard, self-priming and priming assisted pumps.

Buy centrifugal pumps from vendor that offer quality products and good prices

Many distributors or vendors provide online catalogs of centrifugal pumps. By browsing through online catalogs from different vendors and comparing centrifugal pump prices, you can narrow down your selection of products and find some good deals.

I recommend: PumpBiz is a distributor of pumps with a huge selection of products that offers online shopping. Look through the different type brands of centrifugal pump products and compare prices. Grainger also offers a good inventory of this product including self-priming pumps.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  A high-pressure centrifugal pump is a good choice for applications that require high discharge pressures and flows. These pumps can discharge at a rate of 100 gallons per minute and can produce heads well over 200 feet.

Centrifugal pumps use a rotating rotor inside a tube to increase the flow of a fluid, and are commonly used to move liquids through a piping system. They allow fluid to enter the rotor near its rotating axis, which accelerates the fluid into a chamber. The velocity of the fluid is converted into pressure due to the shape of this chamber, which increases in volume. This increase in pressure causes the fluid to flow into the downstream piping system.

Action Steps
The best contacts and resources to help you get it done

Impeller

An impeller is a rotor inside a tube that rotates to increase the flow of a fluid. It transfers energy from the centrifugal pump motor to the fluid that it pumps.

I recommend: Kiwi Pumps provides a detailed description of impellers and the different types that are available.

Cavitation

Cavitation is a condition in which the centrifugal pump impeller does not receive its maximum supply of fluid. This can occur due to a reduced flow of fluid or over rotation of the impeller. Cavitation can frequently be identified by observing the fluid flow.

I recommend: On Site Energy provides a more complete definition of cavitation and also describes some of its consequences.

Multistage pump

A multistage pump is a centrifugal pump that has more than one impeller within the same casing. The purpose of this arrangement is to increase the flow of fluid.

I recommend: The Water Environment Federation offers a glossary of waste water terms, including multistage centrifugal pumps.

Jet Pump

A jet pump is a centrifugal pump mounted to a surface that uses an ejector to increase its suction. This type of centrifugal pump is frequently used in deep wells.

I recommend: Affordable Solar Group defines a variety of terms used for water pumping, including "jet pump".

Vertical lift

The vertical lift is the vertical distance that the water is pumped by a centrifugal pump. The vertical lift of a centrifugal type pump does not increase when the pump is submerged.

I recommend: Northern Arizona Wind & Sun describes a number of terms related to wind and solar power, including a more technical definition of vertical lift.

Pressure head

The pressure head represents a fluid's energy due to the pressure it exerts on its container. It indicates the height of the column of water that the pump can move. The pressure head is typically expressed in feet in the case of centrifugal pumps.

I recommend: Cole-Parmer defines a variety of terms related to liquid pumps, such as the term "head".