Control Valve Advances Made Water Softeners User-Friendly
In my last article, I wrote about the steps that a typical water softener goes through in the regeneration process. These include back flushing the mineral bed, brining and rinsing the mineral bed, and usually a fast flush to resettle it. This is all accomplished by a control valve. Control valves vary widely in their design, and it seems every softener manufacturer has its own type of control valve. I believe that many manufacturers do not manufacture the control valves on their units, but purchase them from companies that only make control valves.
In my working years, I have seen many control valve designs — some pretty simple and some rather complicated. I’m going to write about the advantages and disadvantages of these designs. The first water softeners I ever saw when I was just a young man were regenerated manually using a series of globe and gate valves. By opening and closing the valves, the operator could produce the four processes needed to regenerate the softener. The upside of this was that manual valves are pretty darn reliable and a malfunction would be unusual. The downside was that the person doing the regeneration had to understand what valves to open and close, and to not make a mistake.
Another downside to this manual regeneration system was that the operator had to keep track of the time each process took. In other words, if he or she moved the valves to accomplish a backwash, the softener would backwash forever until the operator came and moved the valves. Especially important was the timing of the brine-and-rinse cycle. The whole process of regeneration probably did not take much more than an hour or an hour and a half. But that was time that the operator had to pretty much sit and watch it, or perhaps read a book or magazine. I believe some of these early units did not have a brine tank so the operator had to measure a certain amount of salt, open the unpressurized mineral tank, pour the salt in and then continue the regeneration process. You can understand that this procedure would indeed regenerate the softener, but it was time consuming and, frankly, a pain.
The next step — at least in my experience — in designing a control valve was a unit that had a shifting lever. This lever looked just like the shift lever on a four-speed manual transmission in a car or truck. The operator merely moved the lever through positions one, two, three and four. He or she did not have to remember what valve to open and close. The operator still had to keep track of the time, but this gear shift system was an upgrade from globe and gate valves. My father sold a number of these units, and I recall that they worked pretty well and had the big advantage of having a brine tank so the owner/operator could put a bunch of salt into a tank or tub and then siphon out just what was needed using the gear shift control valve. At this point, things were getting easier for the operator.
The next step in improving the regeneration process was to furnish an automatic control valve. Most of these, even today, use electricity of some voltage and that electricity operates solenoid valves, small motors and other power-producing units. Each has its advantages and disadvantages. I have never seen or sold a softener with a perfect control valve, although some are pretty close. I had no experience with the first of these that my father sold, but remember him saying they were a pain. In other words, he had some trouble with them.
The first units that I was involved with selling and servicing we sold in the early 1960s. I remember an official of the Michigan Department of Public Health telling me that virtually all groundwater in Michigan was safe to drink right from the well. He further commented that, by the 1960s, most housewives would not tolerate hard iron-laden water. He was absolutely 100 percent right. This man was a PE and retired years ago. (If you read this Don, I hope life is going well for you.) At this point, we began to sell a fair number of automatic softeners on many of the wells we drilled.
The control valve of these units consisted of two pistons that moved back and forth to accomplish regeneration. This was done using water pressure and, as I recall, the pressure was controlled by low-voltage solenoids. When you stood in front of this softener, it was something like a person looking back at you with the pistons behind clear caps looking like two eyes. In the service position, the pistons were in the out position, and by moving them in and out, the valve could accomplish the necessary tasks to regenerate the softener. These pistons were made of plastic and had a number of O-rings and other non-metallic seals. They had to be rebuilt from time to time in some waters more often than others, and they were just a bit tricky — not really difficult, but tricky — to repair. In later models, these pistons moved inside Teflon cylinders. This improved their performance a lot. The upside of this control valve was that we had a pretty reliable automatic valve, and all the owner had to do was set the frequency of regeneration and keep some solid salt in the brine tank.
The downside of this design was that if the water going into the softener was not really clear and clean, the pistons would malfunction. The malfunction usually occurred in the last step of regeneration — the fast flush portion. So you had a softener putting a lot of water down the drain and an upset owner who had to put the unit in bypass until you got there to service it. The answer was to supply nice clear water to the softener, which resulted in filter sales and that cured that problem. I had one of these in the first house I built, and we lived there 21 years and it was still working fine when we moved to our current home. It was a good design if it dealt with clear water.
Next time, I will write about some of the several other control valve designs I have seen over the years.
Last month, I wrote that my lawn was all dried up. We have since had abundant rain, and my lawn is looking green as can be. I had to mow over the last weekend as I write this on a Monday, and the grass was a bit too long for good mowing. My trusty John Deere tractor, however, continues to do a good job. ’Til next time, I hope you have the advantage of washing up with soft water after a hard day’s work.
For more John Schmitt columns, visit www.nationaldriller.com/schmitt.