Review on FangKingNo Adapter Fittings Install Industrial by Sean Young

I have not used them for plumbing but to attach PVC pipe legs to a piece of plywood and they have worked great. I simply drilled a hole in their ends and threaded a bolt through a couple of them on either side of the plywood and attached them to the plywood, then attached short lengths of PVC pipe as legs to stand the plywood on edge. They were ideal for this use as they have flat ends to press against the plywood. For the installation I would suggest using regular PVC end caps you can get at the hardware store - they seem to be stronger than these.