Can the balance line and the control air line be hooked together via a tee connection?
No. Do not tee the balance line and control air lines together. Each of these air lines has its own specific purpose and should not be tied together. The control air should be the cleanest driest air available since it supplies air to the control air circuit to operate the pneumatic actuating cylinder which functions best and lasts longer if clean dry air is used. The balance line allows the air in the reservoir to move out leaving room in the reservoir for the incoming liquid. This air contains moisture that would be drawn across a tee fitting tied to the control air line. Then that moisture would be pulled directly into the control air circuit, which can damage control air pathways and the air cylinder. If you need assistance, contact Drain-All to help with selecting the proper piping arrangements.