8mm pipe bending

Discussion in 'Tech/Mech General' started by Mattyjwr, Mar 7, 2015.

  1. Mattyjwr

    Mattyjwr Funster Life Member

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    I'm installing an auto changeover valve and regulator and need to replace a rubber hose with 8mm copper pipe. I have a 10mm pipe bender that does a pretty good job of creating the 90 degree bends but the pipe is crushed more than I would like (although, no where near flat). Does a reduced bore make much difference with gas or am I better off using elbow joints or bending the pipe with salt or sand inside?
     
  2. NickNic

    NickNic Funster Life Member

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    Yes, it weakens the pipe on the bend. You need to get an 8mm bender or spring.

    Where in Beds are you? I've got a 8mm pipe bender you can borrow if you want?
     
  3. Mattyjwr

    Mattyjwr Funster Life Member

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    Thanks. We're in Bedford. Do 8mm benders have formers? I've heard that many do not and I wondered what effect that had on the final profile.
     
  4. oldflemo

    oldflemo Funster

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    B & Q have 8mm external springs in plumbing section
     
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  5. NickNic

    NickNic Funster Life Member

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    Mine does I think. The profile is fine. I'll dig it out of the garage later and double check.
     
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  6. Mattyjwr

    Mattyjwr Funster Life Member

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    Thanks.
     
  7. Mattyjwr

    Mattyjwr Funster Life Member

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    I haven't had much luck with springs - do the external ones just reduce the are in which the bend takes place?
     
  8. Manic

    Manic Funster

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    When I put my bbq point in, I made a former with washers.
    Get washers with outside diameter of required bend and stack to thinkness of pipe and then put a larger washer each side and bolt together. Larger washers stop pipe spreading and flattening.
     
  9. Mattyjwr

    Mattyjwr Funster Life Member

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    Sounds like a good idea. I'll have a play later and see if I can set something up like this.
     
  10. mitzimad

    mitzimad Funster

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    if you use sand make sure you get it all out as it will play havoc with lpg jets
     
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  11. Moodybrook

    Moodybrook Funster

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    Can you not get a 90 degree compression joint (y) never played with gas pipes so don't ask me :whistle:
     
  12. oldflemo

    oldflemo Funster

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    No not really I've bent 8mm copper to less than 90 degrees with no real problems other than getting the pipe back out of the spring (Applied lubrication always helps!)
     
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  13. Mattyjwr

    Mattyjwr Funster Life Member

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    I have 90 degree compression and solder joints but I would prefer it if I can create a 90 degree bend effectively. I am fine with wet plumbing and have leak detector gas and a gas alarm plus a friendly heating engineer who can check for me once installed.
     
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  14. Mattyjwr

    Mattyjwr Funster Life Member

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    KY, washing up liquid or something more dedicated?
     
  15. jockaneezer

    jockaneezer Funster

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    The secret to using bending springs, internal or external type is to bend slightly further than you need, then straighten it back to the required angle, this helps stop the spring jamming against the pipe when you come to remove it (y)
     
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  16. gus-lopez

    gus-lopez Funster

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    By keeping tight against the side you can bend around a small paint tin without losing shape. Failing that if you have insulation to go over pipe fit it first then bend & it will do so without crushing.
     
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  17. pappajohn

    pappajohn Funster Life Member

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    Depends how tight the radius is.

    A large radius with soft copper can be bent slowly by hand.
     
  18. Peter A Forbes

    Peter A Forbes Funster

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    The Rothenberger (sp?) benders are worth buying for doing a nice bend, the cheapo copies not so good.

    I use springs a fair bit, used to do air brake conversion on trucks and that was on steel pipe.

    Peter
     
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