In this method, in place of a rubber or Styrofoam disc, the manufacturer provided the installer with a product called “stars.” Now these so-called stars looked something like a miniature space ship. The middle was a round or semi round piece of, I think, polyethylene or some other floating plastic and the top and bottom had some supports in a cross pattern. I believe the center round part was small enough to go through a 1-inch pipe.
The first time I ever saw these stars they were provided with a buried tank that was combined with a pitless adapter and was called simply enough, a pitless adapter tank or PAT. Now this buried tank was really something. It had some real advantages and a few really, really bad disadvantages compared to the so-called standard tank. I will write about these devices in future columns when I discuss pitless adapters.
The first of these PAT tanks, as they were called, were designed to be used with an air bleeder system on the drop pipe of submersible pumps. As with any bleeder system this proved to be really troublesome with water that was hard and had high iron content. The manufacturer of these tanks then went to some sort of rubber disc as I recall, but they would have been extremely difficult to manufacture with this disc inside. So after a number of years they began to provide these so-called stars. These would come with the tank but packed in plastic bags, the number of bags being dependent on the size of the tank.
During the installation the installer was expected to pour these stars into an access tube that connected to the top side of the tank. As I recall that tube was tapped for 1-inch pipe size and the stars went in fairly easily even if you did spill a few. The idea was, of course, that the stars would float on the water and keep the water and air separated to at least help prevent water logging. Oh yes, to keep these little buggers from going out the discharge line the manufacturer provided a cage that was inserted into the outlet pipe or fitting on the only outlet of this tank.
I don’t know if these stars were that much better or that much worse than a rubber air disc or a Styrofoam one either. They were a unique idea and could have been used in a conventional tank although I never tried this. If my memory serves me correct, I think one manufacturer provided a tank that had some sort of liquid that was lighter than water and floated on the water surface inside a conventional tank, providing a barrier to the interface between the water and air. I never did really see one of these as ready to be installed but I did hear about them. They even had some sort of float device which would close the inlet/discharge hole if the tank became nearly empty so the separating liquid would not be lost.
As I have said repeatedly all these methods to keep the water and air apart inside a pressure tank were a big step forward from just a plain old tank. Gone were the air pumps, bleeder valves, diaphragm devices, springs, boosters and what have you that the industry had used for years to keep some air in tanks. Perhaps the biggest advantage was the simplicity of the air separator system. A fellow could make decent money running around with a small car or a mini pickup air charging tanks needing only a small air compressor and, perhaps, a garden hose. That is, of course, if the owner was willing to pay for this service — many times they were not.
So sometime in the early 1960s somebody or, perhaps, a group of people at a manufacturer figured out a way to completely separate the water from the air in a tank, hence the origin of what has become known as the bladder tank. If I’m not mistaken the first of these tanks were an up-rated version of an expansion tank that had been made for many years. These expansion tanks were used on hot water boilers made for heating and other purposes. Of course when water is heated it expands slightly and the hot water boiler system needed an air tank that contained water too to handle this expansion. I think originally just plain ordinary tanks like the plain pressure tanks our industry used were what were installed.
I know that I lived in a house that had a very nice hot water heating system and about once a year I would have to drain the expansion tank. Being in the water and pump business this was no big deal for me, but I can see for the average homeowner it could have been difficult. Anyway, the originators of the bladder tank realized that the pressure tank on a well system was in effect nothing more than an expansion tank, although it worked on far higher pressures than a hot water boiler. So they beefed up their expansion tank, made it out of stainless steel originally and offered it to the water well and pump industry.
Now these early bladder tanks worked very well in my experience and they had only one real drawback; they were fairly small in size. One of their great advantages, which is common to any bladder tank, is that they could be pre-charged making a small tank as effective as a much, much larger conventional tank. This was a major advancement in that no matter what the pre-charge was it would be maintained. In other words the pump could fail, the power could go out, or whatever and the tank would maintain its pre-charge. In fact they were, and are, shipped from the factory pre-charged and we were advised to check that charge before taking the tank out of the box. If the pre-charge was low or, perhaps, 0 psi, the tank was a dud and should not be installed. I don’t think I have ever found a dud when opening the box of one of these tanks.
Next time I’ll write about how the manufacturers got around using stainless steel in bladder tanks and some good and also rather bad things I have experienced with them.
We are in the dog days of August here in Michigan with fairly high humidity and enough rain so that we are all still mowing lawn. When you read this, Labor Day will be over and it will have been back to school for the kids and grandkids, and I hope your favorite football team is doing well if you follow that sport.
For more John Schmitt columns, visit www.nationaldriller.com/schmitt.