Three months ago, I installed a Cycle Stop Valve (CSV) and removed the large pressure tank after doing the same for a neighbor over a year ago. He just called me to say that his pump went out and the technician who serviced his well told me it was due to the CSV causing the bearings to go out on the pump. After speaking at length with the technician, he told me he has had to replace several pumps which use a CSV and in every case, it was the bearings went out on the pump. Now I am wondering if I should replace the CSV with a conventional tank as it was for many years.
OMG! Find a different pump man that knows what he is talking about. Bearings in pumps do not go out from the low flow conditions of a CSV. The new style Franklin impellers are crap, and will not take low flow from a CSV, Dole Valve, or even a ball valve, but it has nothing to do with bearings. The thrust bearing in the motor can be destroyed with less than 1 GPM, but the CSV has a 1 GPM minimum, so that is not a problem.
Usually the pump installer just doesn't know what he is doing and picks a pump that cannot build enough pressure to shut off the pressure switch. That will melt impellers in a pump, but not the bearings. The CSV is just a good scapegoat for an installer who gets something wrong or just uses cheap pumps. If he can't figure out what he is doing wrong, it is easy to blame it on the CSV. I wonder if he even knows the difference between pump bearings and the impellers? It doesn't sound like it.
Tell your neighbor to send me the old pump and I will tell him what really caused it to fail.
Now there are some pumps out there that are having bearing problems. I believe Craigpump said they are Pentair pumps.