Results 1 to 14 of 14
  1. #1
    Dis-member
    Dougal's Avatar
    Join Date
    Nov 2005
    Last Online
    12-06-2019 @ 10:27 AM
    Location
    Head Rock
    Posts
    3,507

    Hot water supply

    A question for DD perhaps.

    A friend of ours advised me that when fitting a hot water supply he had to use copper pipe installed by the AC team, the reason being:-

    1) The glue available is not a proper solvent and when the normal blue pipes are used the joints seperate and water leaks result.

    2) He also has corrosion problems with the flexible pipes used for the last few cms between pipe and sink. He puts this down to the flexible hoses being cheap fakes but I am wondering whether he has salt in his water supply (he has his own bore hole). Or he may be getting a cathodic reaction between the copper pipe and the flexi hose couplings.

    On the first point, I jointed a couple of blue pipes into a 'U' shape with Thai Pipe glue from HomePro and tried to twist it apart. Although there was some evidence of stress around the joint the actual pipe broke at the junction with the 'L' bend connector rather than the glued joint coming apart.

    I am going to try the same test later today but put one end of the pipe into boiling water and see if the glue deteriorates under heat.

    Anyone else had any problems like this or want to comment.

    Confirmation that any of the above is bollocks and that his plumbers don't know how to glue a pipe together is fine by me.
    Lord, deliver us from e-mail.

  2. #2
    RIP
    blackgang's Avatar
    Join Date
    Dec 2006
    Last Online
    08-07-2010 @ 08:33 PM
    Location
    Phetchabun city
    Posts
    15,471
    I have had the glue joints come apart from just being in the sunlight for a time and the water therein was not really that hot and have put glued joints in very hot water and had them come apart, and I had roughed the surface before gluing both the pipe and the inside surface of the fittings, so I know that they were glued properly.
    I have not had really good luck with any plastic pipe or fittings here in Thailand, the quality of the glue is poor and the threaded fittings do not have true NPT threads but more like machine threads that are cut straight instead of tapered like they should be.
    And I have had to replace the shielded flexable hose fittings also, I think they are made to sell and not for their service quality.
    And I do not have salt in my water as we use harvested roof water and stored in Thai 1500 liter water jars [21 jars in system] so unless there is some salt in the cement jars it should be OK.

  3. #3
    lom
    lom is offline
    Thailand Expat lom's Avatar
    Join Date
    Jan 2006
    Last Online
    @
    Location
    Trapped in an old mans body
    Posts
    8,316
    Quote Originally Posted by blackgang
    And I have had to replace the shielded flexable hose fittings also, I think they are made to sell and not for their service quality.
    10" - 80Baht - Made in Thailand - Crap !
    10" - 200Baht - Made in US/Italy - Good

    Usually you will need a "gender changer" adapter to connect the
    flex to the wall outlet. Don't by cheap iron or galvanized ones.
    Brass is a bit more expensive but they don't rust or corrode.
    May the bridges I burn light my way

  4. #4
    Thailand Expat
    Whiteshiva's Avatar
    Join Date
    Dec 2005
    Last Online
    29-05-2019 @ 04:45 AM
    Location
    Nontaburi
    Posts
    4,632
    Quote Originally Posted by Dougal View Post
    A question for DD perhaps.
    2) He also has corrosion problems with the flexible pipes used for the last few cms between pipe and sink. He puts this down to the flexible hoses being cheap fakes but I am wondering whether he has salt in his water supply (he has his own bore hole). Or he may be getting a cathodic reaction between the copper pipe and the flexi hose couplings.
    Most likely the latter. Galvanic corrosion due to connection between dissimilar metals. Copper has a very high standard potential compared to most other common metals like Iron, Aluminium, Zink etc.

    Where does the corrosion appear - on the inside or outside of the pipe?

  5. #5
    Dis-member
    Dougal's Avatar
    Join Date
    Nov 2005
    Last Online
    12-06-2019 @ 10:27 AM
    Location
    Head Rock
    Posts
    3,507
    Quote Originally Posted by Whiteshiva
    Where does the corrosion appear - on the inside or outside of the pipe?
    I haven't seen an actual example - I will try to get hold of one.

  6. #6
    I am in Jail
    stroller's Avatar
    Join Date
    Mar 2006
    Last Online
    12-03-2019 @ 09:53 AM
    Location
    out of range
    Posts
    23,080
    That's odd, I thought those flexible steel pipes had a plastic core?
    As for the 'glue', it's a plastic that fills the gap between the surfaces joined, the solvent in it slightly etches the surfaces, but doesn't "weld" them together. A soldered copper joint is much stronger, of course, but as to the question: I don't know whether the blue pipes are suitable for hot water, I mean, how hot is it, how much pressure, one should ask.
    There is a yellow pipe available, which is of higher quality than the blue and cheaper than copper, I think, and won't cause any corrosion.

  7. #7
    lom
    lom is offline
    Thailand Expat lom's Avatar
    Join Date
    Jan 2006
    Last Online
    @
    Location
    Trapped in an old mans body
    Posts
    8,316
    Quote Originally Posted by stroller
    There is a yellow pipe available, which is of higher quality than the blue and cheaper than copper, I think, and won't cause any corrosion.
    Same quality, different colour. Yellow is used to indicate the pipe carries electrical wiring of high voltage.
    The grey pipe, often used for electrical in houses, is actually intended for low voltage like door bells, telephone, intercomm.. Now tell that to the Thai´s..

  8. #8
    Dis-member
    Dougal's Avatar
    Join Date
    Nov 2005
    Last Online
    12-06-2019 @ 10:27 AM
    Location
    Head Rock
    Posts
    3,507
    Quote Originally Posted by stroller
    There is a yellow pipe available,
    Are you referring to the yellow conduit that the electricians use to run cables in?

  9. #9
    I am in Jail
    stroller's Avatar
    Join Date
    Mar 2006
    Last Online
    12-03-2019 @ 09:53 AM
    Location
    out of range
    Posts
    23,080
    Oops, didn't know this is for electric, I used some for making models, the moulding and surface is superior to the blue.

  10. #10
    Thailand Expat
    dirtydog's Avatar
    Join Date
    Jun 2005
    Last Online
    @
    Location
    Pattaya Jomtien
    Posts
    58,775
    Yellow is for electric, the fittings dont fit as good as the standard blue pipe, for hot water runs us copper pipe, although the fittings will be of a differant metal and cause corrosion, nothing last forever

  11. #11
    Member jumbo's Avatar
    Join Date
    Jul 2006
    Last Online
    04-11-2018 @ 12:59 PM
    Posts
    239
    Hi Dougle

    I am in the middle of having a home built, the question of what water pipe to use, I decided to use copper pipe for hao and cold water. It was a close call between copper and a pipe called multi pipe. The multi-pipe is manufactured in Germany, it has a white plastic inner covered by a aluminium layer finaly coverd by a secon layer of plastic. The joints are also plastic. The 15mm pipe is sold by the meter 91 baht per meter and the 20 mm is sold in 100 meter rolls. I found this product in Kanyong (Pattaya). The sales guy put me off by saying they had seen several connections fail. I started to use copper and after a short time (or long time in preperation) found myself sorry I had not used the Multi-pipe. Copper is working out at the same price but much more work in fitting.

    Phil.

  12. #12
    Member jumbo's Avatar
    Join Date
    Jul 2006
    Last Online
    04-11-2018 @ 12:59 PM
    Posts
    239
    Sorry Dougal for the poor spelling.

  13. #13
    Dis-member
    Dougal's Avatar
    Join Date
    Nov 2005
    Last Online
    12-06-2019 @ 10:27 AM
    Location
    Head Rock
    Posts
    3,507
    Quote Originally Posted by jumbo View Post
    Sorry Dougal for the poor spelling.
    No problem

    We will use copper for the hot water as that seems the conservative and safe thing to do. As someone else pointed out earlier, the double ended thredeed male couplings are straight cut rather than tapered and I really can't see how these could NOT leak after a short period of time.

    I still haven't dome my test of boiling up a glued joint to see what effect it has.

  14. #14
    lom
    lom is offline
    Thailand Expat lom's Avatar
    Join Date
    Jan 2006
    Last Online
    @
    Location
    Trapped in an old mans body
    Posts
    8,316
    Quote Originally Posted by Dougal
    the double ended thredeed male couplings are straight cut rather than tapered and I really can't see how these could NOT leak after a short period of time.
    Using a lot of teflon tape is the secret to keep them sealed.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •