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A hypothetical question ??

Discussion in 'Plumbing and Central Heating' started by rich4nancy, 5 Oct 2011.

  1. rich4nancy

    rich4nancy

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    New condensing boiler to be fitted 24kw conventional with 22mm gas connection.

    Gas is 22mm copper at meter then joins inch iron (unseen) and appears elsewhere.

    Would it in any way contravene gas regs to connect 22mm copper back to the iron to supply new boiler? (pending sufficient gas pressure is there) ?

    So in simple terms it would be 22mm copper - inch iron - back to 22mm copper.

    Cheers
     
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  3. mrgas

    mrgas

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    There shouldnt be a problem but.........................................
    I'm sure your registered gas installer will be able to check whats what and keep it all legaland safe.
     
  4. rich4nancy

    rich4nancy

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    Cheers mrgas

    it was my understanding that minimum pressure drops must be adhered to but does it matter whats actually carrying the gas ? whether it be copper/iron/lead etc?
     
  5. dcawkwell

    dcawkwell

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    Any metal fitting approved for gas is ok.
    No plastic inside buildings.
     
  6. rich4nancy

    rich4nancy

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    Thanks

    I suppose what im getting at essentially is if the start of run is 22mm copper then connects to inch iron(which will be smaller internal bore) then back to 22mm copper you are changing down a size to then increase again. ok if pressure is sufficient?
     
  7. spraggo

    spraggo

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    22mm copper is outside diameter where as 1" iron pipe is inside diameter.
     
  8. Dan Robinson

    Dan Robinson

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    Which your rgi can advise you all about :rolleyes:
     
  9. Charnwood

    Charnwood

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    The OP may have measured the actual OD of the iron pipe, and not be stating the nominal bore.
     
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  11. Agile

    Agile

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    You obviously dont know that iron pipe is designated according to the internal thread size. So what you have measured as 1 " on the outside is actually just 3/4" in the inside.

    The other problem is the iron is rougher on the inside and with higher gas flow resistance creates more pressure loss.

    As stated your gas registered installer will deal with the measurement/calculation of the pressure loss which must be less than 1 mB.

    You do have a registered installer dont you ???

    Its odd that you have never asked him or even referred to him?

    Tony
     
  12. bell824

    bell824

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    Lead is now a no no subject but your rgi installer will know this! he will recomend what exacly is required as stated before!!
     
  13. rich4nancy

    rich4nancy

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    Tony

    As per the title " a hypothetical question" i havent referred to my rgi because there isnt one. Hence why im here. I work within the industry and heard someone say (with 32 yrs exp) that you "cant size down then up again" i was merely asking if the pressure drop is within boundaries is it ok to do this with the pipe, pending the material is suitable for gas internally ie copper/iron.

    cheers
     
  14. kevplumb

    kevplumb

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    when the flying do you internally thread black iron :?:
     
  15. Charnwood

    Charnwood

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    When it's an elbow, socket, tee etc. [​IMG]
     
  16. Dan Robinson

    Dan Robinson

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    Damn too quick :LOL:
     
  17. kevplumb

    kevplumb

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    thats a fitting not a pipe smart ass :rolleyes:
     
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