Letters

Ms. Canning:

I enjoyed your article very much. Your discussion of Mistake #2 is, I believe, the most serious problem associated with pumping problems.

However, I believe your choice of quoting your references as you did has resulted in some potentially poor advice. I believe that one of the greatest disservices that pump manufacturers have institutionalized is the concept of "minimum flow." You quoted Mr. Marscher as saying: "In either case, if it's run much of the time below the manufacturer's recommended 'minimum continuous flow,' then system pressure "

In my experience, operating a pump near the manufacturer's stated minimum continuous flow is never a good idea. Pumps should always be operated at BEP. I know this is a broad statement, but I have found that compromising from this position will ultimately lead to pump failure.

One could argue that operating at BEP will cause an unfair disadvantage in operating cost , i.e., wasting electrical resources. This will not happen if you select your pump properly to match the system needs. (Mistake # 1). One additional overhaul a year due to operating away from BEP can easily cost more than your additional electrical consumption due to recycling fluid to maintain BEP.

I always enjoy your magazine and always come away learning something or reinforcing a important concept.

Ms. Canning:

Thank you for an excellent article. Your statement: "To realize true sustainability, the world must address not only environmental concerns, but also social and economic factors" is truly thought-provoking and timely.

The limited natural resources of energy and raw materials, the need to reduce damage to the environment and the need to create jobs and feed the growing world population demand that we continuously "rethink our processes," and colleges and universities worldwide should integrate that thinking into their curriculum. Again, thank you for an excellent article.