Larry Bachus
(a.k.a. “Pump Guy”)

From: John D.
Sent: Monday, July 10, 2008 1:50 PM
Subject: Replacement Parts

Attn. Mr. Pump Guy,

For over 20 years, I have been the maintenance shop engineer at a Chicago-area chemical plant. I always read Flow Control magazine and collect all of your articles. I appreciate what you do for the pump-user community. I need your help.

A small, obscure pump manufacturer supplied many of our original pumps when our plant was built. Now that company has gone off shore, and we need to replace many parts.

The “suits” say there are no funds to purchase new pumps. We really need impellers, volutes, wear rings and other parts.

One sales rep offers pirated knock-off parts. Another sales rep says he can reverse-engineer and recreate our degenerated parts. Another salesperson says the original pump company still exists in China, and he offers to import our parts. Can you offer any advice?


John D.


Good to hear from you. You have an excellent opportunity to turn your lemons into lemonade.

You say your original pump supplier was a small regional manufacturer. Some small pump companies don”t get involved with impeller design and casting. They buy impellers and volutes from larger pump companies that design and develop these components. In that sense, some pump companies have always been re-sellers of knock-off, pirated parts.

Although your pump company no longer exists, your replacement parts may exist. Go to the Internet and search your pump company name, serial and model numbers. You may find a buy-sell Web site with new and used pump parts for your pumps at a discount. Who knows? Your pump company may still exist under a new name.

A few companies specialize in reverse-engineering of impellers and other pump parts. Some of these companies regenerate your exact part and metallurgy. Another company may regenerate your parts and upgrade them with lightweight carbon-composite construction.

I had the occasion to witness a 600-lb. stainless impeller in brine service regenerated as a 65-lb. composite impeller. The brine was problematic for the stainless, while the composite part was impervious to the brine and weighed a fraction of the original part. Just imagine the energy savings to power a part at 1/10th the weight.

You can send these companies a worn part, and they can regenerate (reverse engineer) it. You might learn that they had already regenerated your exact parts for other customers. Your parts may even be on file or in stock.

Most PD pumps have parts that are unique to that pump and can’t be switched or traded. However, with centrifugal pumps you can morph one pump into another by changing and upgrading failed parts. You can usually mate a pump brand “A” impeller to a pump brand “B” shaft and volute with a little machining.

All standard centrifugal pumps with a four-inch suction nozzle will have an impeller with an eye that can receive the flow through a four-inch orifice. And the impeller diameter and speed will govern the discharge head the pump can generate. Of course, the pump companies don’t want you to do this. They say it will void the factory warranty. But when was the last time a pump company made good on a warranty? You must protect your interests.

You say your company management won’t let you purchase new pumps. I don’t know your company policies, but I learned years ago that some companies play a shell game called “Hide the Money.” Management says spare parts are bought with the daily maintenance budget, and new pumps are bought with the capital expense budget. It’s interesting how the bean counters preach and whine about “Lean” and “Productivity,” but no one notices that you could buy 60 new pumps for the money, time and effort spent on maintaining one old inefficient pump. And when you rub their noses in the facts, you are accused of not being a “team player.”

I learned (Economics 101) that income stops just after production stops. You didn’t buy those pumps, and you didn’t sell the pump company off shore. You can use your parts shortage to your advantage.

I imagine you have a few hundred pumps in your plant. Some pumps handle production, others move feedstock, others run in the powerhouse, others with the cooling tower and others with water and waste treatment. You could perform a test and dedicate a few pumps in each group to pirated knock-off parts, a few pumps in each group to regenerated parts and a few pumps to imported parts. Then you will have the evidence to decide which avenue to pursue to keep your plant running.

Anytime you mix and match pump parts, the pump performance curve will reflect the change. So be sure to plot your new curves, and mate them with the system curve. Don’t forget the instrumentation.

Good luck,
Larry Bachus (a.k.a. “Pump Guy”)

Larry Bachus, founder of pump services firm Bachus Company Inc., is a regular contributor to Flow Control magazine. He is a pump consultant, lecturer and inventor based in Nashville, Tenn. Mr. Bachus is a member of ASME and lectures in both English and Spanish. He can be reached at

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