Originally Posted by VocalNeal
Even your superior? Hitachi constant pressure pumps are described as shallow well pumps. Don't know where you got the idea that they are not.
If they don't need an initial prime why is there a priming cap?
The pressure switch setting for a Mitsubishi 150 w pump are on 1.4 Kg/cm and off at 1.9 kg/cm
Very shallow water supply maybe, but no kind of actual 'well'.
If you are using it to pull water from a water source then yeah that changes things, maybe, but in OPs case the pressure from the volume of water in his storage tank permanently negates any need for prime or to ever think about it.
Regardless there is no point to remove a check valve from a system like this.