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fostapex to copper transition

naphelge Member Posts: 9
I am planning to install fostapex for a home heating system. I will need to make multiple transitions from the fostapex to copper pipe. I've seen the pex press fittings that have a sweat connection on the one end, but I would prefer one with a compression fittings instead, but I have yet to come across one. Do they exist?


  • JeffM
    JeffM Member Posts: 178
    Are you looking for something that is PEX Press x compression? There isn't a one piece fitting like that, but you can make it up from the Viega SVC connection system. Get an SVC coupling, and put the PEX Press adapter in one end and a copper compression adapter in the other.
  • hot_rod
    hot_rod Member Posts: 16,286
    This should work as an inexpensive transition fitting.
    I doubt the manufacturer of the tube would warranty a failed connection, however, if that is important.

    A standard 5/8 compression coupling, a poly ring for the FostaPex end.

    I modified the Viega stripper tool to allow it to cut more jacket off, so the ferrule slides down enough that the tube sticks out beyond it.

    I would go with a poly ring from Parker or other top brands, make sure it is made from a material to handle the temperatures you will be running.

    I could also come up with a multiple pieces Caleffi fitting, it would be longer and may be $$.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Paul Pollets
    Paul Pollets Member Posts: 3,508
    Viega makes a FP to copper Propress coupling. Use them all the time.