Replacing water connector and stop to cpvc. Do I use both purple primer and cement to fittings and pipe?

If it says to do it that way on the cement you are using, yes otherwise the cement won't properly hold.

If you use Primer on both, pipe and fitting, your connection will be "welded". Welded connections hold more pressure than connections without Primer. We always use Primer regardless of pressure. I suggest you do the same.

Good luck with your project. Milo

The Twink and Milo nailed it.
The reason for PVC primer is to remove the glaze from both pieces so the cement will react.
PVC cement is much more then glue, as Milo points out. It melts the two surfaces so they "weld" together as they set up and cure.
Our inspectors make us use purple primer on our drainage so he knows we primed it but where the fittings can be seen, (such as under the sink we're allowed to use clear primer. Cheers, Tom

Hi OM

CPVC has very specific primer. As Twinkiedooter said, read your cement can and purchase the primer recommended by the manufacturer. Using the wrong primer could result in a poor weld... ;)

Mark

Not many folks read instructions on cans anymore... I do all the time as I want to ensure what I buy does work for me.