Leak between two stopcocks with shared water main. Old stopcock not working so can't fix leak until mains turned off by Affinity water

[norriet]

Hello,
In my kitchen got a leaking elbow joint between an old original stopcock and another newer stopcock which was fitted later at some time. The old stopcock also has a tiny trace of leek where the handle spigot turns so this stopcock needs replacing. The mains water pipe which the older stopcock is connected to seems to be 22 or 25 mm steel pipe. The stopcock then connects to about 2 inch 15mm copper pipe to elbow joint just above stopcock and then about 6 inches of pipe to newer stopcock. This older stopcock does not stop waterflow so suspect seal or something has gone. We are on a shared outside water main with 5 other terraced houses so I have to wait a week till Affinity water can turn off the main water supply to allow the pipes to be worked on. The mains steel pipe is threaded which the old stopcock connects to via what seems to be some kind of about an inch and a half extension joint which is completely round, perhaps an old variation. Where the stopcock joins this extension joint there is no seperate nut it is just the stopcock itself with an incorporated nut which seems to be directly screwed on although I can't figure out how that has been done as the stopcock is quite tight to the wall and this would seemingly involve turning the stopcock to thread it into the extension joint. I would greatly appreciate any advice on taking off and replacing the old stopcock. Have included pictures if that helps.

 

[Exedon]

That looks like 1/2 in galvanised steel supply it's a 1/2 in socket with a Yorkshire stop tap screwed in ( 1/2 in bsp male x 1/2 copper )
The stop tap would have had head removed then easily screwed on.
To replace 1/2 male iron to 15mm copper screwed into galv socket then I would use a decent quality 15mm lever valve .
You will need a decent stilson type wrench to hold existing socket before unscrewing old stop tap .
Sort of work I'm well used to unfortunately you have to be a certain age lol.

 

[norriet]

Thank you for your advice and knowledge, it's appreciated. When I get the old stopcock off is it a lever valve with male end straight on to main steel pipe or should I put a 1/2 male compression joint on to main steel pipe and then put 1/2 lever on that.

 

[Exedon]

Male iron to copper into steel socket - stub of 15mm copper then lever valve.
The other option is just to replace existing stop tap head .
Existing valve is made to bs1010 pegler still make them stop taps to that standard.
With water off unscrew existing head and just screw new head in.