A look at their construction features.

You readers probably are saying to yourselves, “Will this guy ever get done writing about old submersibles?” The answer is, “Yes, he has this column, and possibly one more, and then will move onto other topics.” A good driller/pump man friend of mine recently called me, and said that he had read my most recent article on submersible pumps and was very disappointed – he agreed with all the points I made and could not criticize it in any way. Thanks a lot, Dick; your support is appreciated.

In a recent column, I wrote about the internal workings of older submersibles – impellers, diffusers and the like. This time, I’m going to write a little bit about the external or construction features.

The first submersibles I installed pretty much were made entirely of brass and bronze. This included the discharge head and the housing where the water end connected to the motor. These materials worked very well in Michigan, especially with a brass or copper shell, the part in which the diffusers were placed. One very popular submersible that was sold in large quantities in this area had a carbon steel shell, and, in some wells, this was a real problem. This shell would corrode, as would the steel well casings used in those days, and the products of this corrosion, along with minerals in the water, sometimes would “weld” the pump to the casing. To compound this problem, these were very, very well-made pumps, and seemingly would run forever, at least lots of years. When failure did occur, or it was time to pull the pump for whatever reason, removal became very, very difficult, if not impossible. The very few pumps that I ever failed to get out of a well were of this construction.

On the other hand, while pumps with a brass shell could be, at times, difficult to remove – and we’re talking installations in 4-inch wells – I don’t believe I ever failed to get one out. The manufacturer described in the paragraph above eventually went to a fiberglass shell, and while this sounded good, this material had its own set of problems. As years went by, many manufacturers went to a stainless steel shell, and this has proved to be successful; however, some of these same manufacturers went to making discharge heads and motor supports (for lack of a better term) out of cast iron. This was not a good move. In many wells, upon removal of the pump for whatever reason, I was able to “shave” this cast iron with my pocket knife. I don’t believe that I ever did have a structural failure of these parts, though.

As time went by, and manufacturing methods improved, manufacturers came up with some very innovative construction designs. Non-metallic materials began to appear, and while some of these were quite good, others left something to be desired. A rather unique solution one manufacturer had was a non-metallic discharge head covered by a stainless steel shroud – an interesting and successful design. I have heard of failures in the lower portion of the water end where the motor attaches, although I never experienced one of these myself. Of course, this failure would result in the motor dropping away from the pump – not a good thing. The same manufacturer that had the plastic-covered-with-stainless steel discharge head had the solution to these plastic “motor mounts,” and that was use of stainless steel through-bolts, which gave this part great strength.

Speaking of motors, early submersibles had cast iron end bells – that is, the top and bottom of the motor, the parts that held the bearings. These were as subject to deteriorating properties as the pump parts I mentioned above were. For a time, some motor manufacturers used non-metallic material for the end bells, but eventually went to stainless steel or stainless steel-covered end bells, which has cured end-bell problems.

I’ve seen some modern submersibles with totally plastic discharge heads and motor mounts. If the non-metallic materials up are up to the task, and the pump is installed in a casing larger than 4 inches, and is indeed a 4-inch pump, there is nothing wrong with this construction. It possibly is less expensive to make, and the plastic surely will not corrode. With all these different designs, any submersible ever made pumped water as it was designed to do, and usually was a successful product. Water quality probably is the single biggest factor to any successful design, and that is something that is hard for any manufacturer or installer to control – in fact, not only would it be real hard, it’s actually impossible.

Another factor in submersible pump life that has changed with time is resistance to lightning damage. Early submersibles, at least of some designs, were very susceptible to lightning damage – this would not be a result of direct strike to the well casing, but a strike to the power lines either nearby or some distance from the pump resulting in far, far greater voltages impressed on the motor than it was ever designed for. Motor failure always was the result.

I remember one of the first submersibles I installed back in the 1950s came with a so-called lightning arrestor packaged with the pump. This was a “brown box,” actually the size of a small candy bar, with three wires coming out of it. The installer was supposed to attach two of the wires to the power lines leading to the submersible motor, and the third wire to a good ground. A good ground never was defined. Upon returning to this installation years later for some minor repair, not pump failure, I found that I had failed to ground this device; I must have figured it worked by magic. The little brown box on this design arrestor had gaps between the so-called live wires and the ground. A lightning surge or high voltage was supposed to jump the gap and go harmlessly to ground. As I recall, this type of arrestor was not particularly successful.

Later designs also had three wires coming out, with the third wire to be grounded, and looked like a small piece of pipe about 2 inches in diameter and 2 inches long. Another design looked like a child’s whistle made of plastic and again with three wires. I believe one company had an arrestor that was heart-shaped, but again with the three wires. I’m not sure what the inside construction of these updated units was, but for me, they were more effective than the earlier brown box. The key to any of these was how effective the grounding was.

The motors on today’s pumps pretty much all are internally lightning-protected, and are a vast improvement over the motors of the 1950s. This is not to say that they are lightning-proof; I don’t think that particular motor has been built or will ever be built. Lightning itself is a mysterious phenomenon, and intensive from place to place. I know that the area 20 miles to 30 miles from where I operate has far more trouble with lightning strikes than we do close to home. I also must mention that lightning will ruin pressure switches and control boxes. I once was called on an out-of-water job, and the control box looked like someone had put a quarter stick of dynamite in it and touched it off. As I remember, in this case, a new control box got the customer back in water, but that wasn’t always the fix.

Speaking of lightning, the weather report – my monthly comment on the weather – is for thunderstorms, which almost always come with lightning, temperatures in the mid to upper 80s, and humidity a very comfortable 90 percent to 95 percent. Hope you enjoyed this, and are working hard, no matter what your local temp is.