A possibility. The nut profile looks like it might be a Conex brand valve which, if I recall correctly, used to have a non-standard/Imperial thread.What are the chances that the existing nut is imperial?
A possibility. The nut profile looks like it might be a Conex brand valve which, if I recall correctly, used to have a non-standard/Imperial thread.What are the chances that the existing nut is imperial?

Plenty of 15mm compression nuts will screw onto 1/2"The nut will be imperial because the ballcock is 1/2 BSP and the nut is screwed onto it.
It won't make any difference to what you want to do..Just change the ballcock and add an isolating valve.
Exactly.....lots are BSP thread as is the one in the photo.That is why i said it's a straightforward job.Plenty of 15mm compression nuts will screw onto 1/2"

Personally, I'd change the ball valve only, and only if required. A ball valve repair must be the most common plumbing task, I wouldn't over think it. But you could of course go as far as you like.What do you think?
I tried to get a plumber for her but I couldn't. I told her not to get anyone from checkabodger or from the blue van company and I think that was good advice.Only in the plumbing forum!
But, I guess it's easy for us when we've a van full of odds and sods and the know-how to hurdle whatever obstacle is out in front of us...
I get it all the time in my local merchants, where I drink a lot of tea, behind the counter... "what do I need to need to connect this - to this?"
"a fookin plumber" is my usual quib!![]()
I tried to get a plumber for her but I couldn't. I told her not to get anyone from checkabodger or from the blue van company and I think that was good advice.
Now, as you're a plumber how many times have you gone to a job prepared only one thing only to find out the all the rest that was disturbed was leaking after you finished?
Isn't it easier to just change what's needed and add a service valve to that pipe?
The question is: how many times you've changed one leaking part only to find that adjacent parts started leaking after being disturbed?I don't leave leaks.
They may occur post visit due to expansion/contractions/pressure fluctuations, but I check and recheck there are none whilst I'm there.
The question is: how many times you've changed one leaking part only to find that adjacent parts started leaking after being disturbed?
Don't tell me "never" because that's surely not true.
I'm retired, so my time for a friend costs nothing, so why not change 1 extra part for the sake of less than £5?
No, that's why I'm asking advice here.When you weren't "retired", were you a plumber?
Fortunately other plumbers here gave good advice.
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