The above diagram shows early Y-valve shipments used with the Compool LX22 solar control. It had a reversible plug which is no longer used. The LX220 replaced the reversible plug with a three position switch on the rear of the Valve Operator (VOR). If the valve is installed backwards [reverse staged], simply change the switch position to cause the valve to rotate in the opposite direction. The 2 inch Y-valve is no longer available as an option. Current SolarAttic Solar Pool Heater shipments are shipped with a 2 inch T valve. Its output ports are 90 degrees from the input port [forming a T] as shipped and can be adjusted so that any of the three ports can function as an input port by staging the valve differently.