Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Lumpy fostapex?

Options
Hi all

New here..

Local plumber here in Ma..
I have an oil fired hydronic system..system was here before we purchased
They used Viega fostapex to connect the supply and return lines to the boiler to existing blk pipe and baseboard..this morning I had a zone valve fail and while inspecting I noticed a bulge/split in one of the supply lines near the boiler(no leak) and then upon further inspection noticed some of the fostapex appears to be lumpy? Any advice,suggestions etc..is appreciated

Comments

  • hot_rod
    hot_rod Member Posts: 22,467
    Options
    got a pic?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Tinman
    Tinman Member Posts: 2,808
    Options
    Zone valve fail = no water flow; maybe a freeze up that thawed?
    Steve Minnich
    delta T
  • Intplm.
    Intplm. Member Posts: 2,083
    Options
    Freeze up between the layers of the fostapex??? Please provide a few pictures. I have never seen what you are describing.
  • theguynextdoor
    theguynextdoor Member Posts: 2
    edited February 2019
    Options
    Thank guys..Was thinking from the water temp possibly? I believe its rated for 180f ?

    Pictures below..hope it worked. Anyone see them?
  • Intplm.
    Intplm. Member Posts: 2,083
    Options
    Looks like the fostapex is doing its job. Wow! No leaks! Really?!
    In the first and third pictures it looks to me as if water some how got between the layers.
    The third picture might be from when the pipe was uncoiled and had some ripples in it from the coil.
    Never saw the results of the first and second picture. I am looking forward to what others will have to say.
    theguynextdoor
  • hot_rod
    hot_rod Member Posts: 22,467
    Options
    Different about FostaPex is that it has a standard full size pex SDR-9 tube I believe the inner tube is an oxygen barrier tube. The aluminum is just a protective layer, additional O2 barrier with a plastic over it, not really part of the integrity of the tube like aluminum in PAP. That is why the OD is larger than other PAP.

    It does look like something caused the pex tube to expand, freezing, being run over?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    theguynextdoor
  • bob eck
    bob eck Member Posts: 930
    Options
    Send the photos to Viega see what they have to say.
    theguynextdoor
  • billtheplmbr3845
    billtheplmbr3845 Member Posts: 41
    Options
    Had a similar situation, we determined at some time the water temp went above the temp rating on the tubing due to a bad aquastat. The temp gauge your looking at may not be accurate.
  • hot_rod
    hot_rod Member Posts: 22,467
    Options

    Had a similar situation, we determined at some time the water temp went above the temp rating on the tubing due to a bad aquastat. The temp gauge your looking at may not be accurate.

    The Viega site indicates that is hydrostatically tested to 400F? Rated like other pex the higher the temperature the lower the pressure, something like 180F at 100 psi seems to be what everyone lists.

    I think the legal folks start to squirm when you mention listing products over 200F or so, even if the product can easily handle it.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream