PVC trap adapter on galvanized trap?
I am putting a new tub in my bathroom, which includes a new tub drain kit.
The existing plumbing is 1/2" galvanized. The tricky thing is that the trap is right above some ductwork so there is limited space to work with. The end of the trap is 1 1/2" galvanized male. I need to connect my 1" plastic tub drain adapter to this. My first plan was to do this using two PVC adapters: a threaded female 1 1/2" to unthreaded female 1 1/2", connected to a male unthreaded 1 1/2" to 1" trap adapter. These connections would all fit, however, when I use this, the drain is about 1" too high for the tub.
If I were to eliminate the adapters and just use the screw-on part from the PVC trap adapter and use it to attach the tub drain kit to the galvanized trap, this will allow the drain to be low enough. This is how the original construction was done, but the adapter and the tub drain were also both galvanized.
is this appropriate? Screwing the PVC trap adapter "nut" straight on to the galvanized trap? Or should I be worried about mixing materials in this case?