So I'm looking to connect an Aquapure AP102T whole house water filter to my 3/4" CPVC line. The filter housing is plastic with 3/4" female threads on the inlet/outlet ports. My question involves the fittings used to make the connection. (See attached MSPAINT diagram)
My goal is to have the ability to remove the filter housing from the system without cutting the CPVC. It's been suggested to me that in almost every case, brass unions are superior to their CPVC counterparts. Can I use a brass transition union (as illustrated) to make the connection to the PLASTIC housing? Taking into account that this is a cold line, are there any consequences to this approach? Metal threads mating with plastic threads? I'd rather not be stuck using CPVC male adapters and then having to cut the line if a repair/replacement of the filter housing is needed. I really want a union there for easy disassembly! Comments or suggestions?
Also, what method do you suggest for sealing the threads? Telfon tape or pipe dope? I started using Oatey Great White pipe joint compound about two weeks ago and I don't want to put the stuff down! It's approved for most metal types and PVC/CPVC pipe, so I don't really see the need to use telfon tape anymore... Am I wrong?