ForConstructionPros.com

When you have water where you don't want it on your construction site, you need a pump to move it. Deciding what size, power and type of pump, however, can be a challenge.

To help you understand pumps better, we contacted four leading pump manufacturers. These, they say, are the major factors in successful pump selection.

Know the flow
"Required flow has everything to do with sizing a pump system," says Peter Snow, training manager at Godwin Pumps. "Pumps are sized by flow, and a supplier can't provide the right one unless you know how much flow you require."

Mark Conrardy, sales engineering manager for Wacker Corp., adds, "When selecting a pump for a given dewatering application, there are two important questions that a contractor needs to ask: 'How much water do I have to move, and how much time do I have to move it?' This is where flow rate comes into play."

Flow is measured in gallons per minute (gpm). Pumps offer different flow rates, depending on the design. For example, high-flow pumps are capable of moving large volumes of water, but do not create a lot of pressure. High-pressure or high-head pumps can move water over longer distances, but require more horsepower to achieve the same flow rates.