I have a 1.5HP submersible pump with a 120 gallon galvanized tank. Originally, the tank was located in my shop about 10 feet from the well head. The pressure switch was located on the side of the tank about 2/3 of the way up from the bottom of the tank.

About a year ago, I had everything in the well and the pump controller replaced. I also had the galvanized tank moved to the new pump house that was built around the existing well, so now the tank is about two feet from the wellhead.

The work was done by the same guy that originally drilled the well about 17 years ago. One of the things he did was to move the pressure switch from the side of the tank to a nipple that was threaded into the check valve which is about six inches from the wellhead. The check valve also contains the schrader valve. When I asked why he didn't put the new pressure switch on the tank like he did before, he said they don't do it that way any more.

Is there any reason why it should be on the tank vs. on the water line near the wellhead, or vice versa? I plan on adding a CSV soon. Does that have any effect on where the pressure switch should be other than making sure the CSV is between the wellhead and the check valve (and pressure switch)?