DAC, Cancoil Installation Manual
Unit Placement and Mounting - ... Suction riser capacity is the MINIMUM allowable that will return oil up a vertical riser at the given condition. ... Inverted traps should be used at the end of vertical risers to prevent liquid and oil from draining back down to the compressor. ... Vertical suction risers should be installed with a trap at the bottom and should have 1 additional trap per 20 feet of vertical rise. Vertical risers must be sized for proper oil return. ... The control system must be adjusted at start-up for proper operation.