Hi, I've only just registered on this forum and hope there is someone out there that can help. I've just dismantled an old kitchen in our house ready for a new one to be installed. In the process, i unearthed a stopcock connected to the incoming water supply pipe which comes up in the middle of the floor about 2 foot away from the wall. This was previously below a kitchen cabinet and inaccessible. The only way we could turn off the incoming water supply was to turn it off from the external stop tap housed in a grid in the pavement outside our house, or use one of those isolation valves that you turn 90⁰ one way or the other with a screwdriver to turn it on or off. While the kitchen space is clear, i thought I'd try and tidy things up by moving the black water supply pipe near to the wall it comes in under so that the stopcock can be accessed through a hole cut in the back of the kitchen cabinet that will be going in that place.
The problem i have is that there are a series of connections all joined together that reduce the pipework from the black plastic pipe via a series of compression fittings which lead to a 22mm to 15mm reducer that then goes in to the stopcock.
I originally assumed that the black plastic pipe was 28mm outside diameter based on a quick check using a tape measure. I thought i could do away with some of the compression fittings by fitting a new 28mm to 22mm reducer and a new 22mm to 15mm reducing stopcock.
My first mistake. The black plastic pipe is not 28mm. The olive from the 28mm to 22mm reducer was nothing like a snug fit when offered to the plastic pipe. It looked like there was more than 1mm play.
My second mistake. I then thought the black plastic pipe must have been 25mm (i didn't remeasure to confirm this). I found a 25mm to 15mm reducing stopcock. Bonus... i could do away with one more part... the 28mm to 22mm reducer i thought i did need.
My third mistake. The plastic pipe is bigger than 25mm. The olive from the most recently bought 25 to 15 reducing stopcock does not fit over the plastic pipe.
I thought that perhaps it might be an imperial size pipe (the house was built in the mid 80s) but thought i should be more precice in measuring the pipe diameter. I got hold of a vernier caliper and measured the outside diameter. It seems it is 27mm having measured it at a few different places.
Question - is the configuration of this pipework from plastic supply pipe to 15mm copper pipe normal? Is anyone familiar with it and does anyone know what is needed to replace what is currently in this set up?
In case anyone is wondering why i dont just leave it as it is, there was a leak coming from somewhere amongst the compression fittings, somewhere before the stopcock. A plumber came and took things apart and suggested i take the whole setup to a plumbers merchant and let them work out what i need. When he'd left after everything had been reassembled, the leak was even worse. I took it all apart again and reapplied ptfe tape to all the threads and also around the olives this time. This appears to have stopped the leak for now but as far as im concerned, it's been patched up rather than fixed.
I can't take the whole assembly to a plumbers merchant because i can't remove the olive from the plastic pipe without cutting it off. I don't want to cut the olive off until i know i can get the replacement fittings back on the same day. Rock and a hard place you might say.
Any help and advice will be greatly appreciated. Thanks in advance.
Paul
The problem i have is that there are a series of connections all joined together that reduce the pipework from the black plastic pipe via a series of compression fittings which lead to a 22mm to 15mm reducer that then goes in to the stopcock.
I originally assumed that the black plastic pipe was 28mm outside diameter based on a quick check using a tape measure. I thought i could do away with some of the compression fittings by fitting a new 28mm to 22mm reducer and a new 22mm to 15mm reducing stopcock.
My first mistake. The black plastic pipe is not 28mm. The olive from the 28mm to 22mm reducer was nothing like a snug fit when offered to the plastic pipe. It looked like there was more than 1mm play.
My second mistake. I then thought the black plastic pipe must have been 25mm (i didn't remeasure to confirm this). I found a 25mm to 15mm reducing stopcock. Bonus... i could do away with one more part... the 28mm to 22mm reducer i thought i did need.
My third mistake. The plastic pipe is bigger than 25mm. The olive from the most recently bought 25 to 15 reducing stopcock does not fit over the plastic pipe.
I thought that perhaps it might be an imperial size pipe (the house was built in the mid 80s) but thought i should be more precice in measuring the pipe diameter. I got hold of a vernier caliper and measured the outside diameter. It seems it is 27mm having measured it at a few different places.
Question - is the configuration of this pipework from plastic supply pipe to 15mm copper pipe normal? Is anyone familiar with it and does anyone know what is needed to replace what is currently in this set up?
In case anyone is wondering why i dont just leave it as it is, there was a leak coming from somewhere amongst the compression fittings, somewhere before the stopcock. A plumber came and took things apart and suggested i take the whole setup to a plumbers merchant and let them work out what i need. When he'd left after everything had been reassembled, the leak was even worse. I took it all apart again and reapplied ptfe tape to all the threads and also around the olives this time. This appears to have stopped the leak for now but as far as im concerned, it's been patched up rather than fixed.
I can't take the whole assembly to a plumbers merchant because i can't remove the olive from the plastic pipe without cutting it off. I don't want to cut the olive off until i know i can get the replacement fittings back on the same day. Rock and a hard place you might say.
Any help and advice will be greatly appreciated. Thanks in advance.
Paul
). 
