Discussion: An industry standard T-Valve is used to control the water flow rate through the PCS3 attic solar pool heater when pumps will exceed the optimum flow rate of 45-55 gpm (gallons per minute). This could easily occur on pumps that are 1 1/2 hp or larger. The graphic above shows how the T-Valve is plumbed. Cool water enters the T-Valve at the "A" leg of the valve. Water to the PCS3 flows up leg "B" and into the attic solar pool heater. The valve is adjusted to optimize the flow rate for the attic solar pool heater. The excess water from the pump and filter flows down leg "C" and back to the pool along with the heated water coming from the attic solar pool heater. A check valve in the down leg of the heater prevents water from flowing backwards up into the heater.
This valve can be installed as an independent T-Valve for proportioning or adjusting the flow rate to the heater.
Alternatively, this valve could be the solar controller's bypass T-Valve if the cams in the valve operator are properly adjusted to optimize water flow to the attic solar pool heater.