PVC Pipes for water on boats

Discussion in 'Boatbuilding' started by mydauphin, May 12, 2009.

  1. mydauphin
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    mydauphin Senior Member

    I would like have people opinions on using PVC and CPVC pipes for water and graywater, blackwater drainage pipes. Obviously they would have flexible joints at certain points. But could they be used for single long spans with flexible ends.
     
  2. rasorinc
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    rasorinc Senior Member

    They are used in all homes, commercial and industrial constuction and are I.C.B.O. and U.B.C. approved so why not. PVC is not really approved for HOT water but it has a plastic cousin that is. Blue or maybe yellow pipe using a different adhesive.
    Using all copper adds to a galvanic corrosion potential problem in sea water. Even natural gas piping is plastic today and fire hydrant high pressure pipe is a thicker blue pipe and is used extensivly. Use schedule 40 as it is a minimum. schedule 20 is for sprinkler systems and schedule 80 is for high pressures which you will not have. With all the avaiable fittings you do not have to use a flexible pipe.
     
  3. Ilan Voyager
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    Ilan Voyager Senior Member

    There is also a plastic pipe sold in Mexico under the name Tuboplus (made under german licence) by the firm ROTOPLAS. The pipes are green with a liner white inside. Needs a special tool (in fact an electric heater cost about 150 bucks) to join it by fusion.

    Very good stuff. It withstands hot water at 95 celsius (200 F), salt water, black water, some corrosive liquids and UV. I have used it on 2 small boats, and a medium pressure air circuit (about 150 PSI) exposed to the sun and weather: after 2 years as good as new.
    Nice feature the couplings have threaded male and female inserts in a metal which looks like a cupro nickel. Salt water does not oxyde it.

    Before using it I made some crude experiments.
    It's virtually unbreakable: hammer, vise, press, and several destructive devices. It seems impervious to vibrations, you can bend it a 90 degrees and it will come back, it's given for 24.3 kg/cm2 (345 PSI) max pressure I have tried to burst a tube (with the due precautions) using air from a dive cylinder at 600 PSI; nothing happened.
    It's a low modulus plastic Polypropylene Random Copolymer (PP-R). Not rigid, but that outclass all the PVC I know. I do not use PVC on boats because the have a tendency to crack and are unable to accept deformations or flexing. PVC do not age well as I see in my own house plumbing and it's planned to replace it with Tuboplus.

    http://www.tuboplus.com/tuboplus07/ in spanish. It's worth to make a Google search.
     
  4. TollyWally
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    TollyWally Senior Member

    I wonder what a US equivilent might be?
     
  5. rwatson
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    rwatson Senior Member

    PVC pipes accept embedding in Polyester resin very well - forms a tight, bonded connection. A previous boat I owned used PVC pipe as a curved "former" for fibreglass, and there was never any question of disconnection or fracture in the years that it was in use.

    MacGregor yachts embed PVC pipe as an outflow for water ballast into the f/g hull.

    I am planning to do a fair bit of it in my next project. I would give it the thumbs up myself
     
  6. Frosty

    Frosty Previous Member

    This may raise some eybrows here. My exhausts are PVC, twin Yanmar 250HP 6LP turbos with surface props so always up 3500 RPM.

    The first foot out of the turbo is stainless the rest is PVC thick wall blue pipe glued up.

    They are now 5 years old.
     
  7. Boston

    Boston Previous Member

    I have an inherent distrust of plastics
    although as R Watson implies
    plastic sticks to plastic pretty darn well
    so if the rest is also plastic it kinda makes sense
    if its a wood hull
    I would not use plastics in the through hull areas if for no other reason than the expansion and contraction issues with sealant it presents
    best of luck
    B
     
  8. marshmat
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    marshmat Senior Member

    Somehow I think you'd have a hard time finding PVC that meets SAE J2006 for wet exhaust systems. But since Frosty's still alive, I guess it works...

    For potable water you'd want something with the NSF 61 marking, indicating it won't leach anything nasty into your drinking water. PEX tubing is becoming quite popular for potable water, some say it's easier to install. If you do use rigid PVC, it would have to be supported in the middle of any long spans- water is heavy!
     
  9. Ilan Voyager
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    Ilan Voyager Senior Member

    Yes, polyester sticks well to PVC but in this case PVC is rather a lost mold for a GRP pipe. It works but it's better to have a joint (for example a "rubber" pipe) to allow some movement. PVC and GRP are brittle and you'll end with annoying leaks. For example the cockpit drainers are prone to crack if a "rubber" joint is not used.

    The use of PVC in a exhaust: huhhhh I prefer a good synthetic rubber pipe...

    But the "tuboplus" is amazing, really it's worth to try. Rotoplas is known here for his good quality products at fair prices (for once we have a company making good products it's worth to mention it). I do not know if it's sold in the States (a search would give the answer) for such polypropylene pipes.

    Here in Cancun, it's taking the place of the Flow Guard PVC and the copper which became very expensive, as it's better and cheaper. It's replacing also the galvanized steel in the 150 PSI compressed air systems, for the same reasons; better and cheaper.

    In my opinion it has it's place in a boat's plumbing system.
     
  10. apex1

    apex1 Guest

    Thanks Ilan for sharing.
    Rotoplas seems to be a Mexican compny using a German patent. I could not find any other source.
    You?

    Regards
    Richard
     
  11. Ilan Voyager
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    Ilan Voyager Senior Member

    I'll make a search as I have the advantage to read in english, french and spanish. For the german no hope.

    Living in Germany (Hamburg), if I'm not mistaken, maybe you can read german.

    I has been told by a german friend living in Cancun and working in construction that these pipes are well known and used in Germany. Tomorrow I'll post the results of the search. The funniest would be that the Americans have to import it from Mexico :D
     
  12. Ilan Voyager
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    Ilan Voyager Senior Member

    As promised I made a search. I've found everywhere in the world but nothing in the States...astonishing.

    To show what are missing our "amerikanische Freunds" I give an Indian link where you'll some pics and explanations in english.

    http://aquaflow.in/afs.htm

    Admire the nice couplings in metal embedded in the plastic...that doesn't break or leak.
     
  13. mydauphin
    Joined: Apr 2007
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    mydauphin Senior Member

    Once again, very interesting guys. Much to think about...
    Frosty, PVC for exhaust... wow... At least they wont melt underwater line...I guess as long as water flows.... I would love to see Coast Guards or surveyors face... But you gave me idea for inside of muffler....

    In summary, Mexican-German stuff is best. but in a pinch Home Depot schedule 80 pvc is OK.... with precautions on joints....
    I was thinking of making solar water heater with CPVC ... later
     
  14. apex1

    apex1 Guest

    Thanks again Ilan,
    I have it:

    http://www.aquatherm-pipesystems.com/20.0.html
     

  15. Ilan Voyager
    Joined: May 2004
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    Location: Cancun Mexico

    Ilan Voyager Senior Member

    You're welcome. That the purpose of a forum. To share knowledge. Very interesting the german site a lot of good explanations.:)
     
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