Avoid Expensive Mistakes
“There are many different types of process pumps,” Brown said. “We sell at least 12 different types, plus all the accessories. You can easily make a $1,000 mistake if you don’t provide all the information necessary when ordering a process pump.”
Brown added that even the environment where the pump is located can make a difference. “For example, pumping molasses in Texas is much different than pumping molasses in Maine, because the temperature difference in winter can significantly impact the viscosity,” he said.
Provide as Much Info as Possible
As a result, Brown often performs site visits to understand where—and how—the pump will be used before recommending a solution. When ordering a process pump, he recommends providing as much detail as possible.
Start by finding the answers to the following questions. (The Safety Data Sheet (SDS) or Material Safety Data Sheet (MSDS) can provide many of the answers you need.)
Questions—Media Being Pumped
#1—Is the media hazardous or corrosive?
“Remember—safety first,” said Brent Hanson, Business Director of Fluid Power at IBT. “There is a lot of nasty stuff out there. This will help you avoid accidents and select the proper materials for your pump.”
#2—What is the viscosity and specific gravity?
Certain pumps work better with water, glue, grease, or acid, for example.
#3—Is there particulate suspended in the media? If so, what is it? How large are the particles?
Some pumps allow sticks, stones and trash to flow through—while others are better for clear liquid and will become damaged if tiny particles are not filtered out.
#4—What is the temperature of the material you’re pumping?
Temperature effects viscosity. “For example, molasses has a much lower viscosity when it’s warm, and a higher viscosity when it’s cold,” Brown said.
#5—What is the ambient temperature?
#6—Is it operating at extreme heights?
Atmospheric pressure may need to be accounted for (in some cases).
#7—Is it wash-down duty, dusty, or corrosive?
#8—Is it an explosive environment?
#9—Is it a submersible application?
#10—Is it in a confined space (as defined by OSHA)?
#11—What is the available power for operation?
Pumps can be driven by electric motors, hydraulic motors, or air motors. If an electric motor is used (the most common), then you’ll also need information on voltage, frequency, and phase.
Questions—Pressure and Flow
Pump head pressure and flow are very important because pumps are sized using “pump curves.” These are complex charts supplied by pump manufacturers.
These 2 variables are used to determine pump size, motor speed, horsepower, and efficiency. All of these are key factors in providing the right pump/motor combination to maximize performance and efficiency.
“A good pump applications engineer will require this information, especially on large systems,” Hanson said. “Taking a guess at any of this is not a good idea. It winds up costing more time and money in the long run.”
#12—What is the “suction head” or “suction lift” height?
This measures the total height that the fluid is above the pump (suction head) or below it (suction lift). This is important to avoid cavitation and determine head pressure.
#13—What is the required discharge pressure (a.k.a “head pressure,” in psi—or “pump head,” in ft.)?
Pump head can be confusing. Manufacturers need to know what it is (in feet), but people usually think of it in terms of pressure (psi) measured at the discharge of the pump. Basically, they are the same thing.
Head pressure is easy to determine if you have an existing system, or specifications on an existing pump. Just measure the outlet pressure with a gauge. Or, you can provide the pump and motor nameplate information.
If you’re designing a new system, then it can be more difficult. Liquid height differential and the piping configuration need to be taken into account—which may be a good time to call an expert.
#14—What is the required flow rate (in gpm)?
#15—Do you need variable or constant flow?
12 Different Process Pumps—from IBT
- Gear pumps
- Flexible impeller pumps
- Diaphragm pumps
- Centrifugal pumps
- High pressure pumps
- Peristaltic pumps
- Progressing cavity pumps
- Vane and roller pumps
- Drum pumps
- Sanitary/hygienic pumps
- Seamless mag drive pumps
- Metering pumps