Which plastic pipe?? PB or PEX

Discussion in 'Plumbers' Talk' started by Robdiyman, May 4, 2006.

  1. Robdiyman

    Robdiyman New Member

    Can anyone enlighten me as to which pipe is best, as they are both suitable for central heating, easiest to work with and why???

    PB pipe tends to be more expensive, so therefore better????
  2. r2d2

    r2d2 New Member

    Looks like no one knows. :^O
  3. doitall

    doitall New Member

    whats pb pipe
  4. devil's advocate

    devil's advocate New Member

    pb = polybutylene? As used by Bartol on their Acorn range - now Hep20.

    I don't there's much to choose between them - certainly nothing significant by the choice of the different plastics. However, if it's to be used on a CH system, as opposed to domestic water, then barrier pipe must be used as (from what I understand) it prevents air from permeating the wall which would lead to deterioration of the system.

    (Does the 'x' of PEX mean 'barrier', or does it refer to cross-linked polyehtylene?)

    Basically, make sure it has a barrier if it's to be used on a CH system - like 'speedfit' pipe.
  5. SDSMax

    SDSMax New Member

    the X stands for cross-linked.
  6. Robdiyman

    Robdiyman New Member

    Thanks for that guys,

    PB is Polybutylene
    PE-x, Polyethylene cross linked.
    They both have an oxygen barrier, and are both suitable for central heating, I was just wondering if either one was better in you experience, or more flexible, as I can get the PB pipe about 25% cheaper than the PE-x.

  7. Robdiyman

    Robdiyman New Member

    I meant 25% more!! Sorry.
  8. Dick Puller

    Dick Puller New Member

    If your not a Plumber and not using copper, well just use garden hose. You can't be giving a f.ck about the installation really anyway, if your a DIY duffer, EH??

    Listen m8 it will all end up sagging and look like sh.t anyway.

    Dick Puller (Appointed PR guru to 2 shags)
  9. devil's advocate

    devil's advocate New Member

    Hi Robdiyman.

    I think I've read on this forum that pb is, indeed, slightly more flexible and therefore a little easier to handle (I think the thread was about straightening coils! You could try a search?).

    Other than that, I doubt if there is anything significant to choose between them. Some peeps swear by Hep20 (pb, or at least used to be) and others speedfit (pex).
  10. pipefittings

    pipefittings New Member


    Message was edited by: Screwfix Peter due to unsuitable content
  11. sparticus567

    sparticus567 New Member

    Chlorine is a world-famous chemical that is used to purify water. Now the main problem is that chlorine will steadily rupture the PB pipes bonds. At some point of time, PB pipes can become weak and ultimately break due to the water pressure. However, PEX has the greater resistance to control the pressure of water, even with high amount of chlorine. Due to the inbuilt weakness in Polybutylene (PB), the pipe is not accepted in Canada and U.S. as people living in these countries do not use these pipes because of its fragile aspects. Though, PEX pipe are still acceptable in many countries, as it promises the long lasting features that help people save their money and time. Always use inserts if using compression fittings.
  12. Ryluer

    Ryluer Well-Known Member

    Polypipe is one of the largest suppliers of polybutylene in the UK and this "rupture" and "breaking" that you claim is just not an issue.
  13. Rec

    Rec New Member

    To answer Robdiyman's original question, you are probably better using PEX (crosslinked polyethylene) over PB (Polybutylene) for your central heating system to ensure future compatibility with pipe fittings. Now that PB fittings are cheaper they can be appealing but you should be aware of its limitations. It will react with chlorine and become brittle over time from its exposure, as Sparticus567 described especially when dealing with hot chlorinated liquids, but on closed loop central heating systems this is not a problem as the chlorine is removed and replaced with other chemicals to prevent corrosion in the system. PEX is a stiffer pipe which makes it harder to work with if you are trying to bend it into curves because it has a thicker pipe wall to mitigate some of the issues of rupture and leaking experienced with PB pipes. You should also know that most PB pipe types no longer hold an approved WRAS (Water regulations advisory scheme) or DWI (drinking water inspectorate) certificate meaning they are not suitable for use in drinking water applications, so are really only any good on central heating or grey water installations. All types of plastic pipe will require more support than a copper counterpart just because of their inherent flexibility

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