1955 Stopcock

Discussion in 'Plumbers' Talk' started by John_L, Sep 19, 2019.

  1. John_L

    John_L New Member

    In my first-floor maisonette, post-war council build, the mains water supply has a joint main stopcock with adjoining properties, not just the one below. The stopcock to my own property is solid and, judging from the mangled mess caused by Mole grips, has been for some time. It now has a combo-boiler, so no tanks now. Fitting a new kitchen gives me the opportunity to start again but I want to minimise the time the water is off.

    I assume the mains-in is ½", given the age; would this be true?
    I understand that a modern 15mm stopcock with compression fittings will replace it directly; is this true?
    What is the exact spanner size for the old compression fitting and the old stopcock? I have a lot of Imperial AF and WW spanners, in addition to metric, but want to get the correct ones to avoid too much damage.

    Sideways photo!

    Attached Files:

  2. kiaora

    kiaora Screwfix Select

    The pipe with bends in, is that connected to the pipe work between to two stop taps ?
    It’s not clear in photo ?

  3. Heat

    Heat Screwfix Select

    Just needs decent adjustable spanners for to remove the old stopcock and for tightening the new stopcock.
    Adjustable wrench.
    Get an experienced plumber to do it.
    Pipe will be 1/2” copper I would think.

    This wrench or similar I use, but expensive for a DIY occasional user.
  4. dobbie

    dobbie Screwfix Select

  5. kiaora

    kiaora Screwfix Select

  6. John_L

    John_L New Member

    Yes, it is. The 'upper' section previously fed the loft tank (as did the other pipe you can see, for the downstairs maisonette). The 'bend pipe' is the feed to the rest of the services, via the kitchen sink.
    Last edited: Sep 19, 2019
  7. John_L

    John_L New Member

    I've got some adjustables like that but I've also got a workshop full of other spanners, too (ex-mechanic). I can just try some out.
  8. John_L

    John_L New Member

  9. Heat

    Heat Screwfix Select

    You probably will find the old stopcock nuts will be an odd size.
    I understand you being an ex-mechanic would see dedicated open spanners as a professional choice due to their fixed and accurate size, but on a lot of plumbing fittings (but not all) can vary and are soft brass.
    For nuts and fittings that are to be scrapped, I would use grips/pump pliers or adjustable wrenches. Footprint grips are excellent British made grips and not expensive. 7” handy for small work and 9” for bigger connections.

    Also parallel jaw wrenches are excellent on brass and especially chrome fittings, but are expensive.

    Use paste for potable water on compression joints to help olive seal. I use V2 Lube
    Last edited: Sep 19, 2019
  10. Heat

    Heat Screwfix Select

    You will be lucky if you manage to get compatible works for a 1950s stopcock.
    Normally only way is if you have any decent second hand stopcocks (maybe taken from somewhere that the stopcock had little or no use), or very old stock ‘new’ stopcocks
  11. John_L

    John_L New Member

    Thanks! I'll do some forensic investigations over the weekend. You're right, as a retired engineer, I'm used to precision fit! I've also got various adjustables (and big hammers), too. I'm just trying to make sure I don't end up with no stopcock at all...
  12. Heat

    Heat Screwfix Select

    Looks to me like those nuts will loosen okay.
    I also use two of large adjustable wrenches (think 15”) and just make sure they get tightened fully onto the nuts. Grips could hold centre of body of old stopcock if you needed.
    If water could be removed from inside the stopcock then a Roth SF2 torch would heat the nuts.
    John_L likes this.
  13. Joe the Plumber

    Joe the Plumber Screwfix Select

    I'd be amazed if you could undo the working part of the old stop tap unless you removed it and put it in a vice. It would be a great way to damage the incoming pipe trying it in-situ.

    If I were you, I'd thoroughly clean the pipe coming up from the floor back to nice shiny copper and, having turned the water off below your flat, use a junior hacksaw with a new blade to cut the pipe directly below the original stop tap. Support the pipe below the hacksaw with your other hand. De-burr the end, then fit a new stop tap onto the (nice shiny) pipe.

    Once the new stop tap's in place, turn the mains water back on, check for leaks and flush the pipework into a bucket with a hose attached to a bit of 15mm copper pipe in the outlet of the new stop tap.

    That way, you won't be risking straining the old pipework any more than necessary undoing the nuts, and you won't need to remove the old bottom nut and olive from the pipe. The nuts will almost certainly not be the same screw thread as modern stop taps (ie they'll probably be 1/2", but not BSP), so you won't be able to do up a new stop tap with the old nut and olive left in-situ.

    This all assumes you're going to then use new pipework from the new stop tap to run to the flat's existing pipes of course.
    DIYperson and Heat like this.
  14. John_L

    John_L New Member

    This does sound like a plan! I'm going to spend an hour on Sunday studying it. As you write, I really don't want to do more damage, especially catastrophic failure.
  15. robertpstubbs

    robertpstubbs Screwfix Select

    Do you have a Vernier calliper which you could use to measure the size?
  16. sospan

    sospan Screwfix Select

    With all respect John, your not getting any younger :).

    Make life easier as you don't want to be down on your knees battling old bits of brass as Joe says, bite the bullet and get rid of the old fittings and replace them with something new and shiny and easier to use.

    You can then do what the rest of us do and bore our grand kids by waving the old valves in front of them and say "they don't make them like this anymore ......" :D
  17. John_L

    John_L New Member

    Thanks all for the input so far. Update:

    @dobbie: I've cleaned off layers of paint from the primary stopcock and there does not seem to be any identification on it whatsoever. The redundant stopcock for the old tank supply is clearly marked ½, though, while the stopcock further along the feed, probably fitted later, is clearly marked 15-15.

    Now it's clean, the compression nuts and threads all look fine and the stopcock itself has hex-flats. On the assumption that a new 15mm stopcock with compression joints and 15mm brass olives will fit the old ½" copper pipe, I think I can use an OE spanner on the stopcock to reduce movement and remove the compression fitting on the inlet side.

  18. Joe the Plumber

    Joe the Plumber Screwfix Select

    You should be able to undo the bottom compression nut okay. However you've then got to get the olive off the pipe without damaging the pipe to remove the old nut. If you do damage the pipe, you'll end up cutting it off anyway, as I suggested above.

    If the old stop tap is tight on the pipe, you'll have to apply some force to it to get it off. That could damage the pipe.

    I can't help thinking all you've achieved so far is to make a scrap stop tap look nice.

    I'd just cut it off.
  19. Tony Goddard

    Tony Goddard Well-Known Member

    Not sure you will have olives in those fittings, those longer nuts from memory were used with a short lived system from the 50's where you flare the end of the pipe. Could be wrong, but as they are longer than standard and the tap body looks longer than a new one you will be best off cutting them off and soldering in some new sections to a nice new stopcock.
    Joe the Plumber likes this.
  20. Joe the Plumber

    Joe the Plumber Screwfix Select

    I think you may well be right Tony. I've met a few in my time with no olive to remove.

    Cut directly under the bottom nut, there's plenty of pipe there to either extend and then fit a new stop tap or, if the access in future will be okay, just put it straight onto the (properly cleaned up) existing pipe.

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