The 3-way diverter valve is installed on the high pressure side of the pool pump between the pump and filter. You need to choose the easiest place between the pump and filter to install it. If the tubing connecting the two is short and straight, it may have insufficient flexibility to use simple couplings during the diverter install. If your plumbing code allows, you could use unions and/or slip joints (see videos later on this page).
The procedure to install the diverter is as follows:
PVC unions installations have two benefits. First they allow easy disassembly for repair, and second when piping does not have enough flexibility to properly create space for using and cementing simple couplings, they are very useful for joining two pipe sections.
Just like unions, slip couplings are useful for joining two sections of pipe when the pipe does not have enough flexibility to properly create space for using and cementing simple couplings. Unlike unions, they are permanently cemented in place. Local codes should be checked before using them.
Cementing PVC is simple, but if you take short cuts, like not using primer, and not having near perpendicular cuts at the PVC end, the joints may be prone to early failure. Take a look at the videos for good practice tips.
The first video below really helps you understand how to determine the length of pipe needed to join two sections of PVC. It shows how to include the length of pipe that gets inserted in the coupling used to cement pieces together.
You may find the second one useful for installing the diverter.
