How to cap off 15mm water pipe

kimwp

I attempted a small plumbing job and now lots of things are leaking. 

Main issue is how to cap off this pipe (see photo) I thought I would just be able to turn the isolation valve to block the flow, but it's leaking. I think I have two DIY options - cap off the isolation valve or cap off the pipe (which I've successfully reattached to the valve). A cap on the isolation valve would be neatest, but I'm not sure what I'm looking for - I can only find compression end caps - if it's the same thing another compression fittings ie with an olive, I don't think this would be the right thing as there's no pipe for the olive to be compressed onto? Can anyone advise on what I should be looking for? (Or doing - with the pipe or generally in life, I'm open to suggestions at this point)

(I know I've fitted the flexible pipe with the isolation valve facing the wall, I didn't spot that it had one

Vitor

JG Speedfit Stop End 15mm | Toolstation

ThisIsWeird

Hi Kim.
Relax - you've got this
There are a few options for capping off that isolating valve. It you have no future use for it, then you can actually remove the valve itself, leaving just that bottom chrome nut, and then fit the insert part from this fitting on to there: 
https://www.toolstation.com/made4trade-compression-stop-end/p63232?
Or, if you want to cap off the copper pipe that's shown in your pic, then fit all of that fitting on the pipe! That pipe can be cut down in length wherever you prefer.
Or, you can remove the top nut from that valve, and replace it with the blanked nut from that same stop-end linked to above - leave the olive inside to make the seal.
If you are going to be doing more plumbing involving compression fittings, then it's worth getting a wee tub of pipe sealant too - just a wee smear will ensure they're watertight. Use one for 'potable' water like: 
https://www.toolstation.com/fernox-water-hawk-jointing-compound/p14953
Do you have proper tools for this sort of work? For comp fittings, you need two spanners/wrenches. Comp fittings need doing up firmly, but don't overtighten them.

kimwp

ThisIsWeird said:

Hi Kim.
Relax - you've got this
There are a few options for capping off that isolating valve. It you have no future use for it, then you can actually remove the valve itself, leaving just that bottom chrome nut, and then fit the insert part from this fitting on to there: 
https://www.toolstation.com/made4trade-compression-stop-end/p63232?
Or, if you want to cap off the copper pipe that's shown in your pic, then fit all of that fitting on the pipe! That pipe can be cut down in length wherever you prefer.
Or, you can remove the top nut from that valve, and replace it with the blanked nut from that same stop-end linked to above - leave the I've inside to make a seal.
If you are going to be doing more plumbing involving compression fittings, then it's worth getting a wee tub of pipe sealant too - just a wee smear will ensure they're watertight. Use one for 'potable' water like: 
https://www.toolstation.com/fernox-water-hawk-jointing-compound/p14953
Do you have proper tools for this sort of work? For comp fittings, you need two spanners/wrenches. Comp fittings need doing up firmly, but don't overtighten them.

Amazing, thank you @ThisIsWeird, that detail of the different options is great. I think I'll go for replacement of the top nut with the blanked nut if that will work - that's what I was looking for, but wasn't sure if the olive would make a sufficient seal. I've used PTFE tape for the joints I've done so far as I already had it and a history of buying compounds that dry up before being used. (Actually will also use for the blanked nut, thinking about it). But if I decide to do more plumbing, I'll get some. 

I have slip joint pliers that I got as a birthday present as a child when I asked my parents for tools and a 12" adjustable wrench.

Next step is the joint to the tap - that's started leaking, I presume with all my fiddling, but I believe I need a special plumbing tool to get into the recess.

Grenage

Those isolation valves almost always weep.

Assuming this this temporary, the speedfit cap is ideal.  If this is permanent, you should really take the pipe back as far as possible to its feed.  I can't remember if there are any regulations for dead leg lengths (to cut down on the risk of legionnaire's disease), or if it was just guidance.

ThisIsWeird

kimwp said:

I think I'll go for replacement of the top nut with the blanked nut if that will work - that's what I was looking for, but wasn't sure if the olive would make a sufficient seal. I've used PTFE tape for the joints I've done so far as I already had it and a history of buying compounds that dry up before being used. (Actually will also use for the blanked nut, thinking about it). But if I decide to do more plumbing, I'll get some. 

I have slip joint pliers that I got as a birthday present as a child when I asked my parents for tools and a 12" adjustable wrench.

Next step is the joint to the tap - that's started leaking, I presume with all my fiddling, but I believe I need a special plumbing tool to get into the recess.

"I think I'll go for replacement of the top nut with the blanked nut if that will work - that's what I was looking for, but wasn't sure if the olive would make a sufficient seal." That's a very good point - the olive, on its own, isn't designed to seal like this - it is always expected to have a piece of pipe inside it to crush against. So, to use just the outer cap and olive to replace the top nut of that isolating valve wouldn't be normal practice - you'd be trying to seal on to the sharp end of an olive. It should work - provided you don't crush the olive - but I cannot recommend it on second thoughts.

Instead, if you really want to cap off the end of the isol valve, try just the 'cap' part of the fitting, and see if it bottoms-out on the round end of the isol valve - will it 'seat'? If so, the addition of some PTFE or a smear of pipe sealant should make it watertight. Or, if you have a pipe cutter, cut the emerging pipe to within an inch of the isol valve, and slip the whole blanking cap fitting over the pipe - the best and correct way.

Will you be using that isol valve in the future? If not, or 'unlikely', then I'd personally remove it at the bottom nut, and fiut the 'inside' part of that blanking cap on there - jobbie properly jobbed.

The plastic push-fit options are great, and are readily removable again without tools, but you must ensure the copper pipe you are slipping them over has been fully de-burred, or else a sharp edge could cut the rubber O ring which provides the seal. If you have a 'rotary' pipe-cutter - the most common type - then that will/should nicely round the outer edge of the cut pipe, so all good.

"I have slip joint pliers that I got as a birthday present as a child when I asked my parents for tools and a 12" adjustable wrench." Brilliant! That's a good combo, as the wrench is needed for holding non-hex'd fittings, like the bodies of isolating valves (slight 'flats', but hardly!)

Your other tap connection really needs attention too. As you say, the isol valve is facing the wrong way, but it also looks as tho' it's pointing in the wrong direction too - see the direction arrow on its side? Tbh, I have no idea how important this is, as I doubt it's a non-return type? Not just a case of turning it around, as the two ends are different, so you'll - again - need to make up suitable parts.

"Next step is the joint to the tap - that's started leaking" Which joint?

I still recommend a tub of potable jointing comp, tho' - a wee smear, and almost always sorted - much easier than PTFE. https://www.toolstation.com/fernox-water-hawk-jointing-compound/p14953 It should last years - mine has (you just pull off the skin that's formed each time...)

Micron

It looks like when you cut the pipe you damaged the end, it will have to be cut back so the outside of the pipe is smooth and then fit a new olive, the old olive might never seal properly on the damaged pipe.

kimwp

ThisIsWeird said:

kimwp said:

I think I'll go for replacement of the top nut with the blanked nut if that will work - that's what I was looking for, but wasn't sure if the olive would make a sufficient seal. I've used PTFE tape for the joints I've done so far as I already had it and a history of buying compounds that dry up before being used. (Actually will also use for the blanked nut, thinking about it). But if I decide to do more plumbing, I'll get some. 

I have slip joint pliers that I got as a birthday present as a child when I asked my parents for tools and a 12" adjustable wrench.

Next step is the joint to the tap - that's started leaking, I presume with all my fiddling, but I believe I need a special plumbing tool to get into the recess.

"I think I'll go for replacement of the top nut with the blanked nut if that will work - that's what I was looking for, but wasn't sure if the olive would make a sufficient seal." That's a very good point - the olive, on its own, isn't designed to seal like this - it is always expected to have a piece of pipe inside it to crush against. So, to use just the outer cap and olive to replace the top nut of that isolating valve wouldn't be normal practice - you'd be trying to seal on to the sharp end of an olive. It should work - provided you don't crush the olive - but I cannot recommend it on second thoughts.

"I have slip joint pliers that I got as a birthday present as a child when I asked my parents for tools and a 12" adjustable wrench." Brilliant! That's a good combo, as the wrench is needed for holding non-hex'd fittings, like the bodies of isolating valves (slight 'flats', but hardly!)

Your other tap connection really needs attention too. As you say, the isol valve is facing the wrong way, but it also looks as tho' it's pointing in the wrong direction too - see the direction arrow on its side? Tbh, I have no idea how important this is, as I doubt it's a non-return type? Not just a case of turning it around, as the two ends are different, so you'll - again - need to make up suitable parts.

"Next step is the joint to the tap - that's started leaking" Which joint?

I still recommend a tub of potable jointing comp, tho' - a wee smear, and almost always sorted - much easier than PTFE. https://www.toolstation.com/fernox-water-hawk-jointing-compound/p14953 It should last years - mine has (you just pull off the skin that's formed each time...)

It would also require a perfect surface inside the isolation valve for the olive to seal onto. I did a bit of YouTube ad googling and found that there are tap tail adaptors which provide a flat surface to seat onto, so I think one of these and a cap with a rubber seal similar to on flexible pipes is what I'm looking for. (I actually screwed one of these, albeit not capped, onto the cold isolation valve at a plumbers advice, you can see it hiding behind the waste pipe in the picture. - but an ultimate handyman video points out that, while it often does work, it's pushing a sharp, probably not-flat surface into the seal). I've got an idea to fit a bidet attachment to the pipe to see if I want to have a bidet when I redo the bathroom, so I want to keep it "live".

Dense question - I presume I'd have to shut off the stopcock downstairs and drain the system down to the bathroom level if I wanted to remove the isolation valve?

The joint to the tap that's started leaking - I'm not totally sure, how to describe, I'll take a photo and post it.


I'll add the joining compound to my shopping list along with a couple of compression joints and ends caps, feels like a good idea to have some of them around. Any other things for the list?

kimwp

Grenage said:

Those isolation valves almost always weep.

Assuming this this temporary, the speedfit cap is ideal.  If this is permanent, you should really take the pipe back as far as possible to its feed.  I can't remember if there are any regulations for dead leg lengths (to cut down on the risk of legionnaire's disease), or if it was just guidance.

Good to know, thank you! I never run the hot taps myself, so hopefully the legs are already short/cool enough that legionella isn't an issue - I do try to remember to run them for a bit before visitors arrive. The hot water has been set to 38C though for showers to directly come from the boiler since changing to a combo, so maybe I need to think about that.

kimwp

This is what I mean by the connection to the tap. There's a little drip, but I can't work out where it's coming from - all the joints feel dry (IE no wetness on my hand).

kimwp

Micron said:

It looks like when you cut the pipe you damaged the end, it will have to be cut back so the outside of the pipe is smooth and then fit a new olive, the old olive might never seal properly on the damaged pipe.

Thanks @micron, if you are pointing to the bump, that's water leaking from the joint. I've had another go at tightening it until I heard creaky sounds, and that seems to have stopped leaking now.

The lines are my attempt to clean up the pipe to give a smooth surface, I think I did a better job where I was going to place the olive.