Ben Keiser

Founded in 1993, Applied Flow Technology (AFT) is a leader in the pipe flow modeling software market and offers a comprehensive line of products for the analysis and design of piping and ducting systems. On a recent episode of MPT’s podcast, The Efficiency Point, Ben Keiser, AFT’s technical sales consultant, stopped by to discuss the critical importance of proper pump selection and offer his insight on selecting the right sized pump for your application. An excerpt of that conversation appears below.

MPT: Before we talk about how to find the right pump, what are some of the dangers that can occur from mismatching a pump for a job?

Ben Keiser: There are a number of ways that you can have mismatching. And typically, you can have pumps that might be undersized for a particular application. That might be where the plant’s operation has expanded beyond the capacity of what the original pipes were initially sized to be able to meet. Or you can have oversized pumps that are able to provide too much at full capacity, and the flow may need to be throttled down somehow. And both of those situations can cause issues.

If a pump is undersized for a particular application, then it’s not going to provide the required head for the system needs. The system will be starved for flow, and the pump may not be operating close to its best efficiency point and that can cause vibration issues, recirculation issues, or cavitation. You’ll start to see various problems that begin to creep into the pump as well as the system.

MPT: That’s the domino effect that can happen from a mismatched pump to throughout the whole system?

Ben Keiser: Absolutely! And a similar type of problem occurs where people oversize the pump for future expansion, where more flow would be necessary, but—for the time being—they would have to control the flow for current needs. And with having a control valve, it’s like driving your car with your foot on the gas and the brake pad. And that can cause the same type of vibration issues and other problems, in addition to just wasted energy going right out the door. So it’s really important to make sure that the right pump is selected for the right application. 

MPT: And you recommend using flow analysis software instead of just sizing the pump by hand. Is that right?

Ben Keiser: Yes, and the reason why is because when you use a full analysis software tool, it really expands your ability to understand your system—much further than a simple hand calculation. Maybe a hand calculation, you know, it wouldn’t be too difficult to determine what discharge pressure you need on the pump in order to meet a certain flow demand. That’s a pretty straightforward calculation. 

But when you start asking things about other types of operating scenarios, what if you need to have multiple pumps operating at the same time? 

Or situations where the flow’s not needed as much? 

Or how does the system interact when flow changes throughout the day?

There are so many other operating scenarios that can occur that, when you’re just calculating one thing by hand, you’re not getting much out of that. But with full analysis tools, you can do so much more than just looking at the pump itself. You can see how it’s going to actually perform in the system.

To listen to an extended version of this interview, be sure to subscribe to MPT’s podcast, The Efficiency Point

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