bnymbill
New Member
Similar threads have been created but I haven't found the exact answer to my question. I understand that CPVC and copper have the same OD but copper has a larger ID which is why Kohler requires 1/2" copper for the tub supply from the diverter; otherwise water could be forced out of the shower head. My question is, since the Kohler Georgeson has a max flow rate of 2 GPM, why wouldn't 1/2" CPVC be sufficient? In other words, if the flow is restricted to 2 GPM by the diverter, how could it not force 2 GPM through CPVC? Obviously, I'm missing something. In the past, 1/2" copper worked for showers that flowed at 4 or 5 GPM. Thank you in advance!