Choosing the Right Pump for the Application
A successful pumping system starts with more than selecting a pump—it requires understanding the application, operating conditions, and demands of the entire system.
When a pump needs to be replaced or a new pumping system is being designed, it can be tempting to begin with the equipment itself. How much horsepower is required? What size pump is needed? Which manufacturer or pump type should be used?
Those are important questions, but they shouldn’t necessarily be the first ones asked.
The right pumping solution begins with understanding what the system needs to accomplish. Flow requirements, pressure, operating conditions, water characteristics, system design, efficiency, and expected demand can all influence which pump is best suited for the job.
Choosing the right equipment from the beginning can improve reliability, reduce operating costs, simplify maintenance, and help extend the life of the entire system.
Start With the Application
Pumps perform an enormous variety of jobs. A municipal water supply system has very different requirements from a wastewater lift station, agricultural irrigation system, commercial booster system, or industrial process.
Even two systems performing similar jobs can have significantly different operating conditions.
Before selecting equipment, it’s important to understand factors such as required flow, total dynamic head, suction conditions, operating schedule, fluid characteristics, piping configuration, and expected variations in demand.
The pump should be selected for the system, rather than designing the system around a pump that happens to be available.
Bigger Isn’t Always Better
It might seem logical that choosing a larger pump provides additional capacity and therefore a margin of safety. In practice, an oversized pump can create its own problems.
A pump that consistently operates far from its intended operating range may experience unnecessary energy consumption, excessive cycling, vibration, increased component wear, or other performance issues.
The opposite is also true. An undersized pump may struggle to provide the required flow or pressure and may be forced to operate continuously under demanding conditions.
Proper pump selection seeks a balance between current system requirements, efficient operation, reliability, and reasonable allowances for future needs.
Consider How Demand Changes
Many pumping systems don’t operate under one constant set of conditions.
Municipal water demand, for example, can vary considerably throughout the day. Commercial facilities may experience periods of high and low usage. Agricultural applications can change seasonally, while industrial processes may have their own operating cycles.
A system designed only around peak demand may operate inefficiently during the many hours when demand is lower.
Understanding these variations can influence pump selection, system configuration, controls, and whether technologies such as variable frequency drives should be considered.
Efficiency Matters Over the Life of the Pump
The purchase price of pumping equipment is only one part of its overall cost.
Many pumps operate for thousands of hours each year and may remain in service for decades. During that time, the energy required to operate the equipment can represent a substantial portion of its lifetime cost.
Selecting a pump that operates efficiently within the system’s normal operating range can therefore have long-term benefits.
Efficiency shouldn’t come at the expense of reliability or proper application, but it should be part of the conversation when evaluating a pumping solution.
Think Beyond the Pump
A pump doesn’t operate in isolation.
Motors, controls, valves, piping, electrical systems, wells, wet wells, instrumentation, and other components all affect how a pumping system performs. A problem elsewhere in the system can sometimes appear to be a pump problem even when the pump itself is operating correctly.
For that reason, selecting or replacing a pump should include an evaluation of the surrounding system whenever possible.
Simply replacing an existing pump with an identical—or supposedly equivalent—unit may not address changes that have occurred since the original system was designed.
Repair, Replace, or Reconfigure?
When an existing pump develops problems, replacement isn’t always the only option.
Depending on the equipment’s condition, age, application, and operating requirements, repairing or rebuilding the existing pump may be appropriate. In other situations, changes in demand or system conditions may make replacement with different equipment a better long-term solution.
There may also be opportunities to improve controls or modify other portions of the system to address the underlying problem.
The important step is determining why the existing system isn’t meeting expectations before deciding how to correct it.
Experience Helps Turn Equipment Into a Solution
There are many excellent pumps available for municipal, commercial, industrial, and agricultural applications. The challenge is determining which equipment is appropriate for a particular job and integrating it into a system that performs as intended.
Charles R. Underwood, Inc. brings decades of pump application, engineering, troubleshooting, repair, and field experience to that process. Rather than focusing solely on a piece of equipment, CRU works to understand the application and provide a pumping solution appropriate for the customer’s needs.
The right pump isn’t necessarily the biggest, newest, or most powerful. It’s the one properly matched to the application—and supported by a system designed to let it do its job.