Too much pressure on pipe

[Dirtdigger0416]

I installed a cycle stop valve for a client about 7 years ago, but it had started to leak and he wanted to have it replaced.  The old valve was a 50 psi, but I was replacing with a 40 psi.  I evidently did not have enough teflon tape on the threads and after pumping up it dripped from the threads.  I took it apart to re tape the threads and reassembled it.  When I fired the pump again, it blew the glued joints apart on pump side of the valve.  I have not been able to get it to hold at all since the initial installation.  Is it doing this because the shut off pressure may be set too high?  Or is it that the tank pressure was too high after re assembly?  It is for outside water.  They have City water for domestic purposes.

[Cary Austin]

If the pump is the same the back pressure is the same.  It doesn't matter the CSV pressure or the cut off pressure.  But you do need to turn the pressure switch down 10 PSI since you are using a 40 instead of a 50 PSI CSV or it will take longer to fill the tank.

Re-gluing the old fitting rarely works.  Just got to let it dry good before hitting it with pressure.