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Discuss Problem with rising main tap connections in the Plumbing Forum area at

  1. rsk289

    rsk289 New Member

    Our old mains water tap seized, so we had it replaced a couple of days ago. The original was brass, connected directly to the blue supply pipe, with a smaller outlet going to a pressure control valve with a pressure gauge. The replacement is as shown in the photo.
    About 40 minutes after it was fitted, the new copper pipe blew out of the pressure gauge at the joint ringed in red, luckily above the new tap. A call-out saw it replaced again, but the second plumber said the copper pipe doesn't go very far into the valve so the olive is only just held on the copper pipe.
    Should it have plastic pipe into the valve for better location, or is this OK? I'm paranoid that it's going to blow off again. We need the valve as years ago high pressure blew off an underfloor plastic joint and I really don't want to do that again. What's best? Thanks! IMG_4303.jpg
    Last edited: May 13, 2018
  2. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    IF the joint is done correctly and the copper pipe is fully in and the nut is tightened to the correct tighteness it won't blow off

    I would open the lever valve fully as well
  3. Watts

    Watts GSR

    IMO lever valves are much better than brass stopcocks, fit quite a lot of them now. And copper into the vlave is more than OK if its fitted properly.
  4. rsk289

    rsk289 New Member

    Thanks both, a bit of peace of mind's always helpful. We're needing a Megaflo service so I'll ask our independent guy to replace the PRV at some stage as it appears to have seized too. Hopefully he can re-orientate the new one so I can open the lever valve fully!
  5. Watts

    Watts GSR

    Also there should be a double check valve fitted between the lever valve and the drain cock
  6. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    reason why?
    • Agree Agree x 1
  7. Watts

    Watts GSR

    Incoming main needs a protection against backflow
  8. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    back flow of what if it has all the correct air gaps etc
    • Agree Agree x 1
  9. Watts

    Watts GSR

    Well yes if there is backflow prevention and every point of use then not necessary. I was always taught to fit one on incoming main and have carried that on.
  10. Stigster

    Stigster Plumber

    That is not a requirement though. All backflow prevention is at point of use so rarely is there a need for "whole site" backflow prevention on the main. Not to say that fitting one after the stopcock is actually wrong though.

    To the OP, as long as that is all tightened and installed correctly it'll be fine. You don't need to get anyone back to install a check valve but it would be good if a plumber could turn the lever valve around a bit so it can open all the way at some point in future.
    • Like Like x 1
  11. Michael1960

    Michael1960 Plumber

    I think the Strom valve has non return built in.
  12. Ric2013

    Ric2013 Plumber

    I hope he means the previous plumber had cut that little bit of copper pipe too short and the 2nd plumber has now fitted a new slightly longer piece that fits as far into the joint as it will go, and not that the pipe is still too short really. I'm worried, though, that he means the latter. Copper into that joint should be F.A.B., if installed properly.
  13. johnduffell

    johnduffell New Member

    Even if you put a dcv on the incoming to protect the public main, you'd still need to protect your kitchen tap drinking water from any hose pipes, bidet/shower hoses etc.
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