What can go wrong with plunger pumps? An expert answers

My name is Christian Dillstrom and the last ten years I have been a global growth hacker. I am also a business author with over 24 million readers, so I know the value of expert advice.

I have clients from many, many different industries. Today, I am learning about plunger and multiplex pumps which are, for example, used in the oil&gas and water industries.

I’m always looking for new insights, so I am very pleased when I encounter professionals like Joe Bichler, a pump expert from Grand Rapids, USA. The topic of this article series is plunger pumps and how to foolproof and maintain them for best performance.

Joe, your business is all about plunger and multiplex pumps.

How did you come to that passion?

I've known my whole life that women love men who work around pumps, so I figured if I couldn't be one of The Beatles, I could learn pumps to meet women. Actually, I really don't think I had a choice as the son of a family business owner. So I guess it was fate or destiny or whatever you want to call it. It just happened.

It started with a John Bean triplex pump and a 400 gallon chemical tank.

My father owned a pest control and weed spraying business when I was very young. He had a 1 ton truck equipped with a John Bean triplex pump and a 400 gallon chemical tank.

I couldn't have been much more than 4 or 5 years old when I was going with him to spray mosquitoes with DDT. That little John Bean pump took a real beating.

It spent as much time on the bench in the garage being repaired as it did on the truck working. There was always something going wrong with it and I got to watch and learn. In retrospect, I now know that my dad just didn't understand the basics of what was going on with the pump. You know; why it was always malfunctioning. Watching him remove the fluid end and cup packing is still a pretty fresh memory.

Those black plastic John Bean Pump cups

were the first sealing devices I ever saw.

As I grew older and my dad's business grew, so did the sophistication of the equipment he bought. Going from a simple half ton spray rig to the larger more sophisticated Roto-Mist sprayers was quite an upgrade. So much larger and more complicated than the smaller rig. Fortunately, as the business grew, he was able to hire people to help him, even a mechanic.

That was good for the company as well as for me. I was curious about how things worked and now I had someone to show me what was going wrong and how to fix it. I think the mechanic and I learned together. It was a lot of fun and the beginning of my pump education. After that I started working on sewer cleaners and water blasters.

The same kinds of pumps, just different applications.

Over the years I have come to understand that I have a natural intuition about plunger piston pumps and I have learned a lot about what makes them work and what stops them from working properly. It all seemed pretty simple after a certain point. After dealing with pump malfunctions and failures for a long time it finally came a point when everything just made sense.

So, how does a plunger pump work?

A plunger or piston pump is a type of a “positive displacement” pump. A PD pump makes a fluid move by trapping a fixed amount of fluid in a suction port and forcing or displacing that exact exact amount of trapped volume into a discharge pipe.

Imagine filling a glass with water to the point of over flowing. The water in the glass represents the volume trapped in the suction process.

Now imagine submerging one of your fingers in the water. Your finger would displace the exact amount of water equal to the volume of your finger by overflowing the glass. While this example may be an over-simplification of the process, it is a good example of the physical dynamics.

What can go wrong with plunger pumps?

More things than I can think of in a few minutes, but you should understand that they are typically designed for maximum efficiency. Plunger and piston pumps are typically very simple machines with few moving parts and they are very reliable when properly maintained. It makes them incredibly sensitive and temperamental. So if they become even slightly inefficient it can lead to bigger problems.

When plunger pumps are not operating precisely, troubles begin.

Some of the more common problems that I can think of are

•                 cavitation

•                 turbulence

•                 vibration

•                 sticking valves

•                 high pressure leakage

•                 low volumetric efficiency

•                 low discharge volume or pressure.

There are certainly lots more but that's what I can think of now. But while all of these operational problems can be significant and can cause damage to the pump, there are a few very simple things that can be done to prevent them from happening.

And they are cheap solutions.

What was the simplest pump problem you had recently?

Oh man! This is embarrassing. It was simple problem with a simple solution and I missed it. I think I was brain-dead that day.

I received a telephone call from a customer last week whose pump was not working no matter what he did. It just didn’t pump water. After several hours of frustration he called me.

He was embarrassed to let me know that the Y-strainer

on the suction side of his pump was plugged.

I laughed with him because I was embarrassed that I had not thought to suggest he check that. I guess we all miss the obvious stuff occasionally! Thats no excuse though- I used to run that kind of truck.I have literally been around plunger and piston pumps my whole life and every day I am learning and building on this knowledge. Sometimes I just forget things.

Thank you Joe for this interview!

We will continue with the next article and zoom in on problems with seals.