ForConstructionPros.com

Pumps are a common item needed on many construction projects. In a lot of cases, selecting the right one for the job is a simple matter of determining the right type of pump and the correct size. But when you have a large or complex project, it’s helpful to understand a little about hydraulic science.

Successful pump selection begins with asking yourself what you are trying to accomplish, says Pete Snow, training manager at Godwin Pumps of America. Getting a “big picture” view of the pumping application helps determine the questions you need to ask and, ultimately, the design of the portable pumping system required. “Is it a small dewatering job at a construction site for a few hours or days, or is it a large sewer bypass requiring continuous pumping for weeks?” he asks. “The level of complexity dictates the course of action.”

Bill Thompson, president of Thompson Pump & Mfg., cites the following questions to consider:

According to Snow, small dewatering jobs can be handled by gasoline-powered wet-priming pumps with suction and discharge sizes of 2 to 3 in. in diameter. These pumps can run for several hours on a tank of gas and will move up to 250 gpm. “The system design usually includes 20 to 30 ft. of suction hose and 100 to 200 ft. of layflat discharge hose,” he says.

On the other hand, large dewatering or sewer bypass jobs are far more complex, and can involve 24-hour pumping operation and flows up to 4,000 gpm and more.