Stopcock and isolation valves

[Pagala]

Hi everyone

Thanks to the sterling advice of contributors here, my uphill leaky toilet waste pipe is well on its way to being resolved with no hassles.

I have 2 more questions please if you don't mind.

1) I have a leaking stopcock (picture attached). It's a pretty bad leak which appears to be coming from where the knob screws into the stopcock unit. This stopcock is under the kitchen sink, and it shuts off water to the entire property, upstairs and downstairs. I would like to get it properly fixed. What's the best way of doing that? The source pipe below it is a PVC water pipe, with 20mm external diameter. The output pipe above it is copper with 18mm external diameter. Should I ask a plumber to replace this stopcock (and, if so, would he be able to do it with water presumably coming up out of the source pipe)? Or should I ask a plumber to just seal it up (e.g. with solder) and affix a new stopcock above it (in line with the coppoer outlet pipe)?

2) I would like to fit isolation valves to the 15mm external diameter copper pipes in the bathroom. An isolation valve for the toilet, an isolation valve for the bath, as isolation valve for the sink. When I went into B&Q today I was confused by all the different products they had. They had push-fit plastic connector iso valves (I don't want plastic because I want soldered-in iso valves). They had ball-type big valves described as for radiator use, and small ones described as for washing machines. For my purpose (soldered in-line iso valves to shut off supply to those things) would the following product suffice:
https://www.diy.com/departments/compres ... 085_BQ.prd

If not, then which is the correct product to buy?

Thanks in advance

[arco_iris]

1. (a) Before you go to any other trouble, try putting a spanner of the correct size, an adjustable wrench, or if neither available, a pair of unworn grips/pump pliers (in the correct orientation) and tighten the small nut where the white scale is, at the base of the round spindle. Turn the nut a small amount CLOCKWISE, this will tighten the packing gland that prevents water from passing the spindle and quite possibly, more than likely, cure the leak. Do not touch any other nuts, you do not need to turn the water off to do this; do not use excessive force or an incorrect size spanner as this nut is soft brass.

(b) if this fails to fix it, so pray that it does, to replace the stopcock you must lift the lid outside your property (possibly in the pavement) and turn the mains supply off at the valve you will find in the hole. On dismantling the stopcock you will have to catch, mop up, the water that comes out of the system so be prepared with many old towels & a bucket. Then fit a new one of the correct type (20mm MDPE > ??mm copper), should be a straight swap reusing the old nuts & olives.

SFix stock these in 15 & 22mm. Your current set up has an end feed reducer soldered between the stopcock outlet (most likely 22mm) and the 15mm copper pipe rising up from there. Double check your 18mm measurement, don't think thats right.

(c) to fit a new stopcock above, you will still have to fix the leaking gland, though in this scenario you could raipse the gland nut up a bit tighter (when you go too tight, you can't turn the T handle).


2. You will not get a solder isolation valve, they do not exist, the item you link to (15mm compression) is the correct thing to use. You must turn off both hot & cold supplies to the bathroom (possibly in the airing cupboard), clean off any paint either side of the proposed locations using wire wool, then cut the copper pipes very cleanly using a pipe slice.

[wine~o]

arco is correct regards a leaking gland nut, but not on the best fix. Undo the small nut completely (you'll get a minor dribble of water nothing to worry about though)
Wrap ptfe tape round the shaft and use a thin screwdriver to poke the ptfe into the main body, then tighten the nut (don't overtighten)

Repeat as necessary until the weep stops.

EDIT UHM video

[Pagala]

Thanks for the helpful responses guys. I really appreciate it because I haven't the first idea about plumbing, so it's a scramble to Google different issues, etc.

I think this problem is going to be solved as well! I needed to retain a builder to fit some things for me at the property, and he agreed to sort out this problem as a part of the works. If he doesn't, or if his fix fails, then I will surely use the PTFE tape method, which seems like a perfect solution to me, to solve the issue.