@husker posted:Just to add, in a closed system if you maintain the system pressure greater than the low pressure necessary to form the vapor bubbles cavitation won't occur.
the original arrangement placed the pressure setting cap on the swirl, thus the pump discharge. It would be a fair guess that this has the pump suction at 0 or even vacuum (reducing the boil point below 210f
the modifed arrangment moves the pressure setting cap to the pump suction.