yellowfever - 1/12/2019 08:49

The way I read it with your setup you can’t hit the required supply with 3/4 line. You would need 1-1/4” at the minimum to hit 600k at 100ft. Note the pressure drops at each fitting which they compensate for by adding length to the pipe in the chart.

Depending on where the regulator is- your system is only .4psi or 11” wc.

Do you have any gas heaters or cooking stoves or just the water heaters?