yea im ok acknowledging possible or probable over tightening on the fittings, the MPV is my focus as I cant understand how they both cracked the same way within 2 weeks, in middle of the summer. the SWG is after the heater just before water goes back into the pool return jets. so his setup has suction going to pump> filter>heater>SWG. I believe the swg has a flow switch but yes we did wonder if the flow switch maybe gets stuck and cell stays on and builds pressure or something.