today the fisrt stage became operational and is performing beautifully!
After making minor adjustments to the hand expansion valve and replacing some copper line set after the metering device and adding a service port after the metering device the system is able to fully operate
*I had an issue where the copper tubing between the expansion valve and the plate heat exchangers became clogged by silver braze.
the 1st stage has been vacuum tested and pressure tested with no leaks and filally charged with R-507.
here are some updated picstures of the build progress: