Any plumbers in the house?

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IanA2

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I need to change a stopcock valve, it's 3/4". Is that the same as 22mm? In other words can I just do a straight swop...?

Thanks in advance......
 
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I know bugger all about plumbing, but three quarters of an inch (25.4mm) is less than 20mm, so 22mm sounds like quite a bit out.
 
I need to change a stopcock valve, it's 3/4". Is that the same as 22mm? In other words can I just do a straight swop...?

Thanks in advance......

3/4 is as near as you can get to 22mm,, it may be better to just change the washer. A problem could arise if you try and change the whole thing as if the threads are not the same (should be) the olives are now captive on the pipe and you cant get them off with out sawing the pipe,then it will be to short.

If it has been dribling or leaking for sme time you can re seat it
 
I know bugger all about plumbing, but three quarters of an inch (25.4mm) is less than 20mm, so 22mm sounds like quite a bit out.

22 mm = 0.866141 inches

.....So it looks as though unless I can find Imperial replacement parts I'm in for a big job, bugger!
 
Half inch & 15mm are the same diameter, three quarter & 22mm are not. You can get 3/4 x 22mm adaptors though.

Russ
 
why do you need to change the tap
 
3/4 is as near as you can get to 22mm,, it may be better to just change the washer. A problem could arise if you try and change the whole thing as if the threads are not the same (should be) the olives are now captive on the pipe and you cant get them off with out sawing the pipe,then it will be to short.

If it has been dribling or leaking for sme time you can re seat it

Re seat? Tell me more. I'm not sure the washer on the stopcock can be changed. That was my first hope. It has indeed been dribbling/leaking for a while. I can get the olives off with a puller &/or hacksaw.....but then I have to go through the whole business of replacing all the other bits....and there are a few....in the piping sequence. Bugger!
 
If the gland washer is leaking, thats the one on the knob stem where it goes into the tap, the nut can be undone and the gland washer re packed with hemp. maybe just tightening the nut will stop it

If the stop **** cannot be turned off the you can borrow against a deposit a re seating tool that cuts a new face for the washer

A photo would help if possible
 
3/4" is a fitting size. 22mm is a pipe size.
What are the diameters of pipe either side of the stop tap?
 
3/4" is a fitting size. 22mm is a pipe size.
What are the diameters of pipe either side of the stop tap?

3/4" is stamped on the stopcock valve.....have not got round to measuring the pipe size as I still have the olive problem...ie 3/4"!!
 
If the gland washer is leaking, thats the one on the knob stem where it goes into the tap, the nut can be undone and the gland washer re packed with hemp. maybe just tightening the nut will stop it

If the stop **** cannot be turned off the you can borrow against a deposit a re seating tool that cuts a new face for the washer

A photo would help if possible

I'll try tomorrow...
 
You can get olives to suit an imperial to metric change.

By the sounds of it you still have old pipework installed back when China didn't buy all the copper!
 
3/4" is a fitting size. 22mm is a pipe size.
What are the diameters of pipe either side of the stop tap?

On reflection.....if that is the case, why is the outgoing stopcock marked 3/4" and the new one 22mm??

Help...
 
The 3/4" refers to the thread for the fitting (that will be where the tap part screws into the body of the tap.)

The outlets at either side will be 15mm, 22mm or both.
 

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The 3/4" refers to the thread for the fitting (that will be where the tap part screws into the body of the tap.)

The outlets at either side will be 15mm, 22mm or both.

Ah...so in fact I have the right size now?
 
The only times we change stoptaps is when they will not turn off fully.
If they're just weeping from the tap spindle (sometimes happens after turning off then back on) then as TV says, just tighten up the spindle nut.
That will sort it in most cases.
If this doesn't work the post back with pipe size and I'll look into it tomorrow.
 
Old 3/4 inch was the inside diameter of the pipe, whereas new 22mm refers to the outside diameter. They are very close but not the same. However, as previously mentioned, you do get converting olives, and you won't get the old olive off without damaging the pipe.

Your easiest way forward would be to repair the existing tap, which shouldn't require removal at all.

Your next easiest way is to source a replacement 3/4 inch tap and screw it back on using the existing olives and PTFE tape (try a decent old plumbers merchant, you won't get one at B&Q etc).

Next it's the hard way - cut your pipe anywhere before the olive and fit a new 22mm tap using a converting olive. Fit a length of 22mm pipe to the "out" end of the tap, and join it to your existing pipe using a straight union joint and a converting olive. It's not as tricky a job as it sounds if you deliberatley cut the pipes at places to suit, and to give you a decent length to work with.

If you are going to use the converting olives buy them from somewhere that the guy knows which way round they go - it's near impossible to tell.
 

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