Compression fitting for bath tap blew off

Discussion in 'Plumbers' Talk' started by EddieG, Sep 20, 2016.

  1. EddieG

    EddieG New Member

    I am by no means a seasoned plumber but have dabbled a bit around the house in the past. I'm currently redoing the bathroom and was connecting up the bath taps yesterday.

    I'm using flexible hose (one end screwed to bath tap, other end compression fitting onto 22mm copper pipe).

    Connected it all up and started filling up the bath so I could silicone around the edges. When it got to about half full I turned the tap off and all of a sudden one of the compression fittings burst off the copper pipe (Nut, olive and all). I guess this was due to the sudden increase in pressure which backed up from turning off the tap.

    After mopping up the bucket load of water that drenched the floor, I'm left wondering how the compression fitting burst off like that. I put Fernox LS-X around the olive first and then tightened with 9" spanners (felt pretty darn tight at the time).

    I'm surprised that the pressure from a bath tap could blow off a fitting, so I'm a bit perplexed. I'm also now paranoid that the compression fitting on the other tap (which seems to have held fine) is now going to burst off as well.

    Is it just a case of tightening even harder? Could it be olive is not quite right? (seemed fine to me)

    Wondering if anyone has had this happen before

    Cheers
     
  2. Pollowick

    Pollowick Screwfix Select

    One question - how old is the house and original pipework?
     
  3. KIAB

    KIAB Super Member

    3/4" pipe maybe...:eek:
     
  4. You obviously did not tighten it enough for the whole lot to blow off the pipe.
    It was probably a brass olive in the fitting as these are harder to tighten up.
    Or 3/4" pipe which Pollowick is thinking so the olive would not tighten on it as it is smaller
     
  5. EddieG

    EddieG New Member

    The plumbing in the bathroom is just under 10 years old (I didn't do it). I checked and cleaned up the copper pipe before putting the fitting on, and it looked OK to me.

    Pretty sure it's 22m pipe as I measured it before buying the fitting. I'll triple check later but don't think that's the issue - the olive would have been rattling about if that's the case surely
     
  6. KIAB

    KIAB Super Member

    Not the pipe, you, fitting not tightened enough.
     
  7. Pollowick

    Pollowick Screwfix Select

    At 10 year - unlikely to be the pipe.

    As mentioned I was thinking 3/4" as it is just a fraction smaller. Yes the olives would have been a loose fit but would you notice?
     
  8. EddieG

    EddieG New Member

    Gotcha, thanks for the feedback gents, will try doing the fitting tighter (didn't want to overtighten it first time, but I'd rather have a weep than the fitting blow off)

    My paranoia now makes me inclined to tighten the fitting on the other tap to be sure. Unfortunately that's the far side tap and there's not much room to get to it (vertical ended bath with lip sitting right up against the wall - and have already bedded the bath down on a wooden frame with silicone!). Will have to find a way of getting a wrench on though, else I won't be able to sleep at night.
     
  9. Dave does Gas

    Dave does Gas Screwfix Select

    Did you use a compound such as jet blue or boss white? If not that may have contributed to the failure of the fitting
     
  10. EddieG

    EddieG New Member

    Used Fernox LS-X which claims to work as a joint compound (and know other people use it)
     
  11. Hi Eddie.

    Combi or 'Thermastore' type system? Ie - supply to bath is at mains pressure?

    Not that that's the reason, only that you'll need to ensure the compression fitting is done up properly. And almost certainly that's all it was - chust not quite tight enough.

    When you applied the Fernox, did you also wipe a smear over the fitting's threads? Always a good idea as it reduces tightening friction, so you get a better feel for when it's time to 'snick up' the nut.

    You'd have known if it was a 3/4 pipe - the olive would have been faaaar too loose, and even have 'play'. A proper-sized olive should slip on easily and might even fall off under it's own weight, but should really be rattly.

    Have a close look at the pipe before you refit - I doubt there's any mark, ridge or groove where the olive sat? It's quite easy to leave a significant ridge in the pipe with a tightened olive, and getting that sort of 'tightened' olive back on wouldn't be easy...

    Chances are you'll be able to gently tap (use something soft like a rubber handle) that same olive back on to that pipe - in which case it simply wasn't done up quite tightly enough.

    A Fernox smear on the threads this time too.

    (You can over-tighten a comp fitting - but you'd have to be a klutz. So give it a fair doing-up this time with confidence.)
     
  12. EddieG

    EddieG New Member

    Yep, mains pressure - although bathroom is in a basement so maybe get a little bit more than usual

    Didn't put Fernox on the thread, will give that a go next time - and won't hold back with the wrench..
     
  13. teabreak

    teabreak Screwfix Select

    Tighten up undo again and slide the nut smartly against the olive a few times, any movement and it wants a bit more wellie!
     
  14. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    Make sure the end of your flexible pipe is correct(enough copper pipe inserted, correct inner bevel and diameter etc).

    Mr. HandyAndy - Really
     
  15. Jab64000

    Jab64000 New Member

    If it is 3/4" pipe you just need to get a 3/4" olive and it will fit into the 22mm comp fitting. Very difficult to tell the difference simply by looking at them - you really need to measure them with a vernier
     
  16. Dave does Gas

    Dave does Gas Screwfix Select

    Wont be 3/4" pipe he said the house is under ten yerars old
     
    teabreak likes this.
  17. You should have a good idea of the cause when you come to refit the parts, particularly how easy the same olive goes back on to the pipe.

    No harm in trying Teabreak's test to be sure to be sure.
     

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