Those of us who are old enough to have been in the water industry for three or more decades have seen a lot of changes. Was a time when all wells that were even cased used steel casing. Pumps were hung on good old galvanized pipe. Drop cable was solid core copper with double neoprene jacket, just red, black, and yellow, and you had to scrape the copper to get a connection. About eight or ten inches of one of these wires made a great cable tie, and we used one about every ten feet. A one horse power pump and motor had no plastic parts, was about five feet long, and felt like it weighed seventy pounds. All this was installed in the well using a plate and bell, not elevators. You would tighten the bell each time by sticking a cheater pipe through the eye and popping it to the right about three times. Don't forget the bleeder orifice about five or ten feet down from the top of the well. We would cut ourselves a well plate from a sheet of steel. A tee, a union, and a check valve with at least two tapped holes for pressure switch, gauge, and schrader valve were used and everything was screwed together using red lead pipe dope. Then we would hook up the biggest galvanized tank we could get. Usually a 220 gallon tank with an air volume control screwed in half way up the side. Then, if you remembered to tape up the down hole pipe above where you screwed it into the brass check valve, and you regularly replace the air volume control before the float fell off into the tank, this system might work for twenty or thirty years.
When bladder tanks arrived on the scene some of us were hard to convince that the tiny little tanks with an air bag could do the same job as those great big galvanized tanks we were used too. Some places have sulfur or something in the water where galvanized tanks are still needed but lets face it, most of us who still use them are just hard headed. Then they started pushing plastic on us. Plastic drop pipe, plastic casing, plastic well seals, pitless adapters, and of course plastic pumps have all become the norm over the years. Pumps that used to weigh seventy pounds now only weigh thirty four pounds because pump companies don't want them lasting thirty years. Drop cable has only one thin layer of plastic insulation but, it works OK if you don't skin it on the way down. Many other things have changed for the better. Plastic sure won't rust like the old steel would. Even a kid by himself can run one of the new hydraulic pulling units instead of needing three grown men to set it up, as some of the old pole trucks did. But through it all, the only way to know what was best was to try it for yourself.
You decided that plastic drop pipe was OK but, you've got to have steel casing in your area. The next guy decided that plastic was good for everything in his area but, sulfur made the water in bladder tanks taste bad so he still has to use galvanized tanks. The best thing for a different area might be steel casing and drop pipe used with fiberglass bladder tanks because of a corrosive environment outside the well. We all had to figure these things out the hard way. Try it out, keep what works for you and try not to make the same mistake twice. We always learn from our mistakes and learning can be expensive.
In 1993 there was only one company pushing "constant pressure valves" (or constant pressure anything for that matter) at the national trade show in Kansas City. Now in 2005, a short 12 years later, there are so many different ways to do a "constant pressure" system it boggles the mind. Constant pressure valves, variable speed pumps, tanks that fit down in the well, tankless devices, and countless other contraptions are now available. The same way we learned that plastic drop pipe was OK but don't use plastic couplings, we must learn which "constant pressure" system is right for us. We can read literature on how they work. We can ask the manufacturer questions. Taking a class if offered can sometimes help, but we must eventually stick our neck out and try it for ourselves. Just like you did when you first tested bladder tanks, try it on your own pump system. The brother in laws house might be another good place for a test. Everybody has a customer or two that you can't make happy no matter what you do so, what have you got to lose if they get mad again. Successful businesses know that you never change anything in the bulk of your business until you are absolutely sure about the product, but they also know that you risk "missing the boat" if you don't at least try new products and ideas as they arise.
When that customer you can't make happy quits complaining, and your brother in law won't shut up about how much he likes his "constant pressure system", you might be on to something. Give it some time, test a few more carefully. After a couple of years you will know that this one works, that one doesn't, and the other one only made you and your customers mad. With this kind of information you can begin to change the way you do the bulk of your business with as little risk as possible.
"Constant pressure" systems are the only thing I have ever installed that the customer would call and tell me how great they work. Usually a pump company never gets a call unless the customer is already out of water and mad. With "constant pressure", you will hear good things from your customer like, "my shower pressure is so good I almost don't need soap" and, "my sprinklers have never worked this well before". Not so long ago, most of you decided that bladder tanks worked great and you would never use another old galvanized tank. Someday you will decide which "constant pressure" system really works and begin using them on every system you install.
The old saying, "don't trust anything you hear and only half of what you see" is still true today. Tank companies will tell you that "constant pressure" systems waste energy because they don't want to have to start making bicycle seats instead of tanks. Motor companies will tell you all kinds of things about "constant pressure" systems because eliminating cycling makes motors last longer and that would cut into their replacement business. Companies who sell "constant pressure valves" will tell you that they are much better than variable speed pumps. Variable speed pump companies will tell you that nothing can beat their product. After all the dust has settled, you are still the one who must decide what is right and what is wrong for your company and your customers. By carefully trying them all, changing with the times won't keep you under "constant pressure".