Trevor Regulator specifications

This will seem odd but I need to know as much about the specifications of a trevor regulator as possible.

Of particular interest is how low you could get a trevor regulator to regulate to? I know this depends on the spring but I am not sure how to go about finding the right one to regulate to 1.5 BAR from 18 BAR.

Also how reliable would they be reacting to the pressure changes to close before raising it too high.

Thanks,
Haywire

trevor regulator will do any pressure between 0-28 bar