PVC isn't particularly great for holding screws depending on its thickness. It works well to "cap" another material like wood which is a better substrate for holding screws. Screws through PVC into another substrate work well.
I don't know the particulars of your application. When I use PVC I secure it with an adhesive compatible with the PVC and the substrate I'm securing it too.
Not all PVC is resistant to UV
light. If your application will be exposed to sunlight make sure you use the PVC that is.
Good luck with your project!