Replacing 15mm Isolation Valve.. Problem

Discussion in 'Plumbing and Central Heating' started by mortarbo, 17 Apr 2017.

  1. mortarbo

    mortarbo

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    Hi,
    Old house we moved in to seems to have a faulty 15mm Isolation Va lve but because of the way pipes are, theres a problem. No extra pipework to allow me to chop out pipe and fit new valve as all pipes lengths tightly routed. ONLY OPTION IS to unscrew current nuts at ends of existing pipework (that then screws in to faulty isolation valve body). So question is ... can i reuse those nuts (and keep attached still to pipe ends), then just replace isolation valve body (with threaded ends) and reuse current nuts connected to pipe ends?. Or will this bugger up old connections?
     
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  3. mcmoby69

    mcmoby69

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    Should be OK to leave old nuts and olives in place. Sometimes nuts don't fit on new valves but you could split the olives with a junior hacksaw and replace everything.

    Might need some jointing compound round the olives, don't bother with ptfe round the thread, it doesn't work.
     
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  4. mortarbo

    mortarbo

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    Thanks mcmoby69. Someone just casual mentioned i may be wrong assuming faulty if the grub screw turns in existing which it does. Or can innards fail still?
     
  5. dilalio

    dilalio

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    Change it for a lever valve or at least a mini lever valve (like the ones you get on a filling loop). Ballofix isolators always leak eventually - usually from the get go.
     
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  7. REEMS

    REEMS

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    Just replace the the old valve with the new one using the old nut and olives PTFE will be fine but do it around the olives not the thread, nuts should be same size half inch BSP.


    Andy
     
  8. magicmushroom666

    magicmushroom666

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    Are you sure its an isolation valve? If there's a grub screw it might be a one way check valve?
     
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  9. oldbuffer

    oldbuffer

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    Magicmushroom makes a very good point. There's no grub screw in a normal isolation valve, and the small check valve nut is normally hexagonal.

    Also, if the pipework is a tight as you suggest, how are you going to get the pipes out of the ends of the old valve?

    I think a picture of the existing would help us all suggest solutions.
     
  10. FiremanT

    FiremanT

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    Exactly my thoughts. If it IS a valve, and you can fit a quarter turn lever one, you can get them with a "slip" effect, so you can cut the pipe, slide the valve over one end, and then slide it in the opposite direction. But post a picture.
     
  11. DIYnot Local

    DIYnot Local

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