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SCH 80 CPVC for heating?

Solid_Fuel_Man
Solid_Fuel_Man Member Posts: 2,646
in THE MAIN WALL
Was just working on a jobsite (I was wiring and controlling the 4 Viessmann 300's) where the installers were using sch80 CPVC for all the heating pipes outside the boiler room. The engineer didn't want any copper or steel outside the boiler room. This is a saltwater did hatchery, right on the ocean. Steel and copper throughout the boiler room, no isolation of any kind. Am I missing something? Oxygen barrier?
Serving Northern Maine HVAC & Controls. I burn wood, it smells good!

Comments

  • GroundUp
    GroundUp Member Posts: 2,031
    Hmmmm...... I know saltwater takes a helluva toll on heat exchangers for pools unless they're titanium, might be a corrosion thing? I've run a lot of SCH80 CPVC for chemical piping and process coolant (which tends to get up to 150ish degrees) per the engineer's request but never asked why. If it were a corrosion thing though, seems odd he'd allow steel and copper within the boiler room
  • Solid_Fuel_Man
    Solid_Fuel_Man Member Posts: 2,646
    Design temp is 140 degrees.
    Serving Northern Maine HVAC & Controls. I burn wood, it smells good!
  • hot_rod
    hot_rod Member Posts: 22,828
    I've seen fin tube piped with CPVC. Pressure and temperature rating? But no O2 barrier as you suggested.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 16,102
    I think CPVC is supposed to be ok @140 is about the top end I think. Would have to look it up. I wouldn't do it but I am a plastic hater.

    They better put a lot of hangers on it or it will look like crap when the heat gets to it.

    We did a job (not me but my former company) using Aquatherm polypropolyne a few years back. I think their stuff is good for 170 maybe. The hanger spacing gets ridiculous. The hotter you get the more hangers you need. 6" pipe needs hangers every 2-3 feet.

    I didn't work on that job because I was a plastic hater and they wouldn't listen to me about the hangers. You should have seen what it looked like when it got hot. Not pretty, but nothing broke. Aquatherm is good stuff, BIG$$$$$$$$$$ but tough as nails
  • hot_rod
    hot_rod Member Posts: 22,828
    I’m worried about long term plastic of any type that doesn’t have a barrier. We have been down this road with PB and EPDM

    Why does Aquatherm sell a barrier product in Europe?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Solid_Fuel_Man
    Solid_Fuel_Man Member Posts: 2,646
    This was nothing special as far as fittings etc. The installers were laughing about needing to go to a class on "how to properly solvent weld". They said the 100s of thousands of other PVC joints are all wrong! I'll get some pics next time I'm down there.
    Serving Northern Maine HVAC & Controls. I burn wood, it smells good!
  • GBart
    GBart Member Posts: 746
    from one manufacturer- CPVC is similar to PVC, but is treated with chlorine to create a material that is highly resistant to heat, acids, alkalis, alcohols, and many other corrosive materials. Our Corzan® CPVC compound also has impressive fire resistant qualities-meaning it is very difficult to ignite. This may be useful in applications that require ignited heat sources or in situations that are prone to fire.

    With CPVC’s ability to withstand higher temperatures than PVC, CPVC is used in applications where the temperatures may reach 200°F (93°C) and can typically be found in numerous applications including chemical delivery systems, hot and cold potable water distribution systems, chemical processing systems, corrosive waste systems, and vacuum lines.

    I find none with an 02 barrier
  • GBart
    GBart Member Posts: 746
    this was a thread a few years back

    https://forum.heatinghelp.com/discussion/150482/cpvc-in-hydronic-heating-system
    Solid_Fuel_Man
  • HomerJSmith
    HomerJSmith Member Posts: 2,560
    I don't think CPVC is an oxygen absorber. Why not PEX it has a higher temp and pressure rating and is salt water immune.
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,852
    There IS an O2 barrier PVC out there, by Lubrizol if memory serves. No fittings tho...

    ME

    There was an error rendering this rich post.

  • Solid_Fuel_Man
    Solid_Fuel_Man Member Posts: 2,646
    edited March 2018
    This is a spec job. It's all 3" and 2.5" pipe. 1.2M BTU combined boilers.

    The mechanical room is all copper with so.e steel. CPVC outside boiler room.
    Serving Northern Maine HVAC & Controls. I burn wood, it smells good!
  • bob eck
    bob eck Member Posts: 930
    What about using Nyron?
  • Solid_Fuel_Man
    Solid_Fuel_Man Member Posts: 2,646
    It is Corzan, I'm back at this job for a couple of days. 4.5hour drive!
    Serving Northern Maine HVAC & Controls. I burn wood, it smells good!
  • AnthraciteEnergetics
    AnthraciteEnergetics Member Posts: 77
    In the semiconductor industry CPVC is the standard corrosive waste piping, SCH 80 commonly handling hot 140*F sulfuric acid/hydrogen peroxide mixtures, hydrofluoric acid, ozone, and some solvents in all concentrations. We use PVDF for hot (180*F) ultrapure water. Copper and iron is not allowed near process equipment as it causes defects if it contaminates the product even in minute (a few ppb) amounts.

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