Actually the fuel pump is capable of a lot more than 100 psi but if your
regulator bypass is not clogged the pressure in the whole system up to
the regulator bypass should be pretty close to 28psi. This is not like a gas
regulator where it lets higher pressure gas in, its a bypass regulator that
bleeds off until the pressure is down to 28, and just like your brake system
the pressure is uniform throughout the system except in the return line which
is open at one end and thus a lot lower. Note that the fuel comes in to the
fuel loop at a different place than where the regulator is.
--
George Downs, The "original" Walrus3, Bartlesville, Oklahoma