The economizer suction pipe was laid from the top of the economizer tank and then down to the deck, then back up to the compressor again. making it a perfect place for condensation to occur and shoot it into the compressor
Also the NRV valve was placed 2 meters from the economizer port on the compressor, also making it a perfect place for oil to gather during low capacity operation, just waiting to be mashed back in

About the pressure regulator, it's done a bit backwards here, there is an AKVA between the top of the economizer and compressor suction, so if the pressure in the economizer is to high the AKVA will open and bleed the pressure down and not open the main ICS valves until the pressure in the economizer is at the setpoint.