Which is better?. CSV125 valve In well or OUT of well?.

[jbmike7@bellsouth.net]

Currently I have a CSV125 valve located in my Pump House just BEFORE the Pressure Tank and my BACK PRESSURE reading is 170 psi!. I was wondering if I put the valve IN the well say half way down at 50' would that REDUCE my BACK PRESSURE?. My total depth is 100' and I have 1" Poly Pipe rated at 200 psi. with a 1/2 hp motor. As I read the MAX Back pressure for the CSV125 is 150psi. If I read and understood Cary Austin in one of his previous post he explained that every 2.31' of depth in the ground their is a LOSS of 1psi. So if I put my CSV125 at 50' I should see a LOSS of 21.66 psi?. So 170-21.66=148.35 psi?. Did I get my math right?. That would put my BACK PRESSURE at 148 psi, below the MAX rating of the CSV125 valve of 150 psi, Right?.

[Cary Austin]

Well Sort of?  The CSV will have 1 PSI less back pressure for every 2.31" down to the water level.  But installing the CSV further down will actually increase the back pressure on the CSV.  You would need to put the CSV about 46' higher than the water level to get the back pressure reduced by 20 PSI.  You really just need the CSV1A to install outside the well as it can take up to 400 PSI.