Paul,
Thanks for the reply. I'm 27 and just getting into the industrial side of the industry. What I meant by gravity drain is in my scenario I have a VILTER VSM single screw serving a chiller in an air separation plant. As previously stated I'm a halo carbon veteran and in our systems the oil is miscible and returns with run time at a proper head. In low temp applications -25 C we have " oil distillers " and the oil eventually comes back. So to clarify gravity drain... I had a situation where the chiller got too cold and shut off for an extended time and the ammonia left the receiver and migrated to the evaporator. In the process the oil in separator seemed to leave as well. I disabled the high level float and unloaded the screw and closed the hand ex. Valve. I brought the ammonia back to level but the oil isn't coming back. So in regard to this issue I need to find the low sections of the system and drain the oil and add precisely what I recover back to the separator? And this is normal? Where can I go to get more training and exposure? My goal is industrial refrigeration but I'm stuck in the HVAC world. Any advise appreciated! Thanks again
P.s hope all that made sense..,