"Over the last many months, I have discussed many things about older submersibles – their design, build, installation and problems. I finally have nearly come to the end of my thoughts on these great pumps."

Over the last many months (with a side-tracked interruption to write about pick-ups), I have discussed many things about older submersibles – their design, build, installation and problems. I finally have nearly come to the end of my thoughts on these great pumps.

In previous columns, I have discussed design and construction features of what we would call standard submersibles, that is, those that pump water with impellers and diffusers. There is a type of submersible that I will briefly review that had a unique design. I don’t know if this type pump still is made, but I have not seen it advertised in a long time. This pump was, I believe, properly

classified as a progressive cavity pump. It had a regular submersible motor, and this was attached to a screw-like device that was enclosed in a rubber casing. The rubber itself was enclosed in a metal housing, but the so-called water end was far smaller in diameter than even a 4-inch standard submersible pump. I have heard this design described as a wiggle worm by some pump men, and that’s a pretty accurate description. I believe the rotor was made of stainless steel, so this was a rugged design. I think some of these pumps still are used above-ground with regular electric or hydraulic motors to pump on drill rigs.

My father and I had some experience with a shallow-well version of the progressive cavity design in the late 1940s. We did not have real good luck with some of those pumps, usually due to coupling failure between the electric motor and the rotor. This design also featured an aluminum pump housing assembled with steel screws, and this made disassembly very, very difficult. Actually, we had a lot of unusual designs in the post-World War II era, many of which were not very successful. One of the advantages as submersible of the progressive cavity design would have was that this mechanism is much more of a constant-pressure design than is the impeller/diffuser pump usually associated with submersibles. As I said earlier, I have not seen this design advertised in a long time as a submersible. Perhaps I am reading the wrong literature. If any of you readers had experience with this type of submersible, I really would be pleased to learn what that was.

Another design that was a submersible – but it’s not really, and is not really that old – is a submersible water-end connected to an above-ground motor. No, you cannot immerse this in water, but it makes a very effective pressure booster. I only sold a few of these, but the owners were well pleased with them. Actually, using a piece of pipe for the housing and some fittings, including double-tapped bushings and a waterproof connection for the motor wires, a fellow could make his own pressure booster using a regular submersible. I never did this, but I know some fellows who did, and it worked out quite well.

Using a submersible in unusual conditions leads to problems, especially when they are installed in lakes or dug wells, and if the installer does not follow proper installation procedures.

In the early days of submersible use, hand-dug wells – usually about 3 feet in diameter with brick or stone sides – still were fairly common in southern Michigan. As these new-fangled submersibles had much-improved performance over previous type pumps, and were easy to install, they were a natural to be installed in a dug well. We just hung them in on a drop pipe, ran the extended line to a house or barn, turned on the electricity, and we had “water city.” As for cooling, what the heck, we were installing the motor in this great big body of water, which would keep it nice and cool – no, actually, it would not.

What we failed to realize was that the motor needed water going past it for cooling, and in a dug well, the water would go right into the intake, and the motor received no cooling. The result was very limited motor life, although a few that we installed lasted quite a long time, considering the conditions. Of course, we were too wise to read the installation manual, which would have told us to put a shroud around the motor, and then these pumps would have worked very well. I believe the same can be said for low-capacity pumps in large-diameter wells. For instance, a 5-gpm, 4-inch pump set in a 6- or 8-inch casing is going to be a mini version of the dug well installation. A shroud over the pump or motor needs to be installed for this to be successful.

The same can be said for submersible pumps installed in lakes. If they are installed inside a shroud, they are quite successful, and make a great sprinkler pump. A few months ago, I was called to consult on the job for one of these type of installations, and drove there, virtually certain that the motor had overheated and the pump was ruined. Upon arrival at the job, I rather quickly discovered that it was a shrouded installation, and the problem was the discharge pipe had become disconnected at the lake shore where it went underground to assorted sprinkler heads. Upon the reconnection of the pipe, the system worked just dandy. Yes, I did get a nice consulting fee – knowing what to look for still is worth something.

Despite all the design flaws, material malfunctions and installation errors, submersible pumps over many decades have proven to be very successful. They certainly are far more efficient, trouble-free and easier to work on than the pumps they replaced. I once was told that the average life of a submersible was seven years. I find this difficult to believe, as most of the submersibles that I have installed have run two times or three times that long. Now this does not count lightning strikes or holes in drop pipes, which may require the pump to be pulled, and are no fault of the pump itself.

I recently was asked to provide service on an installation that I made in 1992, and found the captive-air tank had failed. Upon my replacing the tank, the current owner, who was a relative of or a very good friend of the person I made the original installation for, told me that this was the first time anybody had laid a wrench, screwdriver or hand on this system. My personal record for pump longevity is a unit that still was running after 32 years, but circumstances deemed it wise to replace it. I’m not saying that this unit had not lost some performance, but the owner who was the original owner had no complaints. Sadly, he had converted a very nice cottage into a lake home and, in doing so, had built a garage, blocking direct access to the well. I explained to him that to replace this pump would require driving my pump hoist truck around the lake side of his house and, in the winter or spring, this would be just about impossible, due to ground conditions. He decided that replacement was the better part of valor, and I replaced the pump on a nice fall afternoon with no problems. I will say that this fellow’s well – drilled by me – yielded pretty good quality water, although it did have some iron and hardness.

A good friend told me he had a submersible installation run 44 years before it failed, and I’m pretty sure that somewhere one of you readers has one that has run longer than that. In any event, the development of the submersible pump has been one of the great advances in our industry; this, along with the rotary rig, pitless adapters and captive-air tanks, has changed private water supply probably more than any other factors.

In my monthly weather report, I am saddened to report that it is nearly 100 degrees F here in Michigan; the humidity is very high, and the air is so heavy that you can cut it with a knife. Hope it is more comfortable where you are.