Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie

Connecting Copper pipe to Gun Barrel pipe.

Options
  • 24-10-2008 3:15pm
    #1
    Wavey
    Registered Users Posts: 861 ✭✭✭


    Afternoon all,

    I am planning on replacing some radiators in my house.
    The old ones are piped with what looks like 3/4" Gun Barrel pipework.

    How can I connect this to 15mm copper pipework?

    I have googled this but cant find anything.

    Any advice appreciated.

    Thanks,

    Wavey.


Comments

  • Options
    #2
    bbam
    Closed Accounts Posts: 7,410 ✭✭✭bbam


    Hi..
    I used to plumb a bit... I think what you are looking for is a "318" fiting.. Ask at any good hardware store and they will have one...


  • Options
    #3
    copper12
    Registered Users Posts: 680 ✭✭✭copper12


    spot on


  • Options
    #4
    311
    Closed Accounts Posts: 5,332 ✭✭✭311


    A 327 would work aswell if you had some 372's for the last pair.


  • Options
    #5
    Micky Dolenz
    Registered Users Posts: 44,080 ✭✭✭✭Micky Dolenz


    Have I missed something? How could I connect GB to copper using a 318 (tee)?

    I would unscrew leg from rad, where it goes into GB elbow. I would then screw a 311(3/4 x 1/2 if needed) into the GB elbow and run copper from there to the new radiator valve.


  • Options
    #6
    Wavey
    Registered Users Posts: 861 ✭✭✭Wavey


    Thanks for the replies lads.

    Where can I purchase these 318 fittings?
    I tried B&Q and Woodies over the weekend but they didnt stock them.

    I have also looked on the Screwfix direct web site but I couldnt find them there either. Unless they were called something other than 318.

    Thanks again,

    Wavey.


  • Advertisement
  • Options
    #7
    Pete67
    Registered Users Posts: 1,257 ✭✭✭Pete67


    Here you go:

    link here

    311 or 312 is most likely the fitting you want. Also available as elbows, 316 or 317. Available from any plumbing supplier or good hardware shop.


  • Options
    #8
    Wavey
    Registered Users Posts: 861 ✭✭✭Wavey


    Thanks for the lenk Pete.

    Although I was under the impression that you needed a special fitting that separates the steel from the copper to prevent corrosion through electrolysis.

    THIS site suggests you use what is called a Dielectric Union.

    Or is this just overkill?

    Also when I measured the existing mild steel pipe it measures 17mm OD. This seems a strange size and is too small to be 3/4" imperial.
    Any ideas what size coupling I need to fit onto this threaded pipe?

    Thanks again.

    Wavey.


  • Options
    #9
    Pete67
    Registered Users Posts: 1,257 ✭✭✭Pete67


    The dialectric union sounds like a good idea, but I've never used one, or seen one used.

    17mm OD steel pipe is probably 3/8" BSP, the threaded portion of which has a major diameter of 0.656in (16.66 mm). The OD of the pipe itself is 17.2mm

    It's a standard size.

    See here:


Advertisement