Water reg valve adjustment on 410-A water source heat pump

[montanabama]

I've been confused about this...
We have several "in and out" water source heat pumps and straight A/C units here. water temps are generally about 53*. Prior to the creation of the 410-A water reg. valve, these units were equipped with a backflow preventer, pressure reducing valve, and a zone valve which opened on a call for heating or cooling. We're retrofitting the systems with reg valves. I've seen smaller units which have dual settings on the reg valves (one screw for heat, one for cool), which I assume are to prevent the coil from freezing. What are some basic points to keep in mind when installing these 410-A reg valves, as far as the setting goes? Am I looking for a certain delta T across my water coil? Or am I looking for a certain head pressure? Any help would be appreciated.

[Six]

Adjust water regulating valve for condenser to maintain 120 degrees liquid saturation in low ambient operation. So for 410A its about 420 psi.