Compression joint leak hassle.

axzed · Mar 13, 2010

Hi all.
I have a leak that I just can't cure.
My mains stopcock is in the concrete floor in a 9x9" hole forcing me to use a tap spanner
It decided to leak from below the input comp. nut.
There is hardly any clearance to drop the nut down to get behind what may be an olive or a flange.
After a few futile attempts I noticed the first few threads on the tap were split.
I dug out an old one, unsiezed it and greased it up.
I have tried PTF & Bossand even fibre & rubber washers!
I am tightening as much as I can but it keeps slipping off, though I reckon I applied plenty of torque.
A simple problem but I have made 10 or more attempts!
Am I missing something?
What is the basic principle with these?
If it was an olive and no danger of disrupting the lead seal, I would be tempted to tap it up.
If I could get behing the olive, I would pack it with TPF. (I have tried this with tweezers)
HELP PLZ

Puddle · Mar 13, 2010

Well you could try this and that but you are not going to get a joint you can trust even if you stop leak and make tight joint for now,you are looking for an easy way out but sometimes there is not one,get your hammer and chisel out and make a bigger area around joint and redo as required,removing olive and if pipe ok fit new or cut back pipe end if damaged to much by over tightened olive and redo from there

axzed · Mar 13, 2010

Thanks.
So you are saying that the seal is the olive/tap joint & not the nut/olive?
Can it be, & what if it is a flange?
Regardless of the working space I can't see how I can prise the olive off as the nut will not back off enough.
How delicate is the lead to copper joint?
cheers.

WHPES · Mar 13, 2010

Remove the nut and olive. As stated you may need to enlarge the area in the concrete.

Sometimes fittings have a different length of pipe sticking out past the olive and if the olive has stuck on the pipe that may be your problem.

The seal is made between the olive and the chamfered part on the body of the tap. A couple of turns of PTFE around the olive will sometimes help.

axzed · Mar 13, 2010

THANKS
" different length of pipe". That's why I wanted to tap the olive up a little.
So I take it, it ain't gonna be anything other than an olive?
Thanks for the 'seal' enlightenment which becomes obvious if it is discernable as a convex olive edge - my vision is sad.
I never known people so eager to whip out their tools and start banging away.
Ta.

WHPES · Mar 13, 2010

The thing you've got to remember is that us pros have power chisels on our breaker drills and it takes no time at all to open up a hole in masonry, whereas if all you've got is a hammer and chisel, then you're going to get a good workout!

stevetheplumber · Mar 13, 2010

if its an underground stopcock it will not be an olive but a union of some sort most probably with a leather washer
if you can run the nut back you could try ptfe or ls or both doubt if youll change it in a 9x9 hole but you might be lucky and pull it up enough to get valve out

axzed · Mar 13, 2010

Sheesh, bach to square one.
So, is the seal the rear of the nut against the union flange?
As I said, I tried inserting PTF with tweezers and Boss to no avail.
Should the washer be in the same gap and is now irreplaceable?
"you might be lucky and pull it up enough to get valve out" er, ? You lost me there 'valve'. Pull what up? Please explain.
I guessed the hole dimensions. I was correct....for the trap door cover rebate,..... but not for the actual well....7x7!!!

I do have a Kango, put not a 'power chisel' of which, I've never heard.

WHPES · Mar 14, 2010

Laymans speak for a Kango.

axzed · Mar 14, 2010

Hi again.
I am now confused and seemingly left with no other option than to repeat that which I was originally attempting.
Please answer my questions and confirm any correct diagnosis.
Is it a union?
"So, is the seal made by the rear of the nut against the union flange?
As I said, I tried inserting PTF with tweezers and Boss to no avail.
Should the washer be in the same gap and isit now irreplaceable?
So I just add more PTFE?
Can I use an alternative?
THANKS

charitynjw · Mar 14, 2010

"How delicate is the lead to copper joint?"

Could you describe this?

& is incoming mains pipe lead?

axzed · Mar 14, 2010

Hi, Yes

WHPES · Mar 14, 2010

Post a photo. You know the old saying "a picture says a thousand words"

axzed · Mar 14, 2010

OK - Tuesday.
But what is the critical seal for a union joint?

WHPES · Mar 15, 2010

We'll wait until you've posted a photo otherwise we may be advising you wrongly as it's not completely clear from your description.

If you are trying to get a new joint onto a lead pipe, the only way is to cut back the lead pipe to it being sound and fit a Philmac universal fitting or a leadlock.

axzed · Mar 15, 2010

Hi,
It's a lead pipe with a compression joint to receive the stopcock. It could be an olive or a fixed union 'ferrule.' I can't stop it leaking from behind the 'nut'. If it is a union, where is the critical seal that I need to 'make' and how can I accomplish this as I have already pushed in PTF and Boss?
I do not wish to dismantle it again just to take a photo, knowing it will still leak as I am tired of repeatedly doing this and I am using the street stopcock which is leaking and may soon become unservicable!
cheers

WHPES · Mar 15, 2010

If the street stopcock starts leaking it is the responsibility of the water board to maintain it.

I would get a pro to come in and sort out your lead pipe union if you are having difficulty.

axzed · Mar 15, 2010

It's only a small leak in the street but it fills the well. They have been told that it has broken months ago! I have jammed a socket on it and use a long wrench bar.
I am only asking for your empirical knowledge here to save time and effort- I am quite capable of applying it.
thanks

axzed · Mar 16, 2010

That photo really helped - thanks guys.
I will bite the bullet and find my own solution.
nice.
THANKS

WHPES · Mar 16, 2010

Just keep phoning them up until they get sick and come and fix the street stopcock.

I thought you were meaning that the incoming pipe was made of lead but from the picture I see that you were meaning that it is copper with lead soldered joints.

You need to get a new stopcock, undo the old one, remove the olives and nuts and fit the new stopcock with a couple of turns of ptfe round the olives.

axzed · Mar 16, 2010

That is the overhauled replacement stopcock and after many attempts, using PTFE & Boss, I cannot stop the leak from below the lower nut.
That's what my whole query is about.
Is it a union, not olives and if so, where do I pack it, as I have tried behind the union/olive?
I can't back off the nut enough to see it.
Are more turns of PTFE counter productive?

franz · Mar 16, 2010

if you cant get to it with two hands thats tricky at best. best bet it to open the floor a bit ,or your just killing yourself struggling.

WHPES · Mar 16, 2010

Open it up and expose some fresh pipework. It looks like it is stepped down from 22mm so get down below this step and fit a new compression coupling then a new section of copper.

Be careful not to damage the pipe when chiselling.

NickH · Mar 16, 2010

Is it just me or does that stopcock look like its on backwards ?

If you've changed it presumably you can get it out of the way and have a look at the olive. You can get an olive puller which should be able to pull it off with the nut.
The incomimg pipework is copper so I would try to solder a new piece of 15mm onto the old piece and get a new stopcock higher up (out of the hole).

Bail the water out of the hole and use a length of thin plastic tubing to suck the water out of the pipework, clean the pipes carefully and use a yorkshire (solder ring) fitting to make the joint.

Can you solder ?

fuzzy · Mar 16, 2010

axzed said:
Thanks.
So you are saying that the seal is the olive/tap joint & not the nut/olive?
Can it be, & what if it is a flange?
Regardless of the working space I can't see how I can prise the olive off as the nut will not back off enough.
How delicate is the lead to copper joint?
cheers.

dont ptfe the thread(if this is what you are doing). My dad did this on a compression joint once, he did it 3 or 4 times then called me. i took off 3 rolls of ptfe from the thread, put a small amount round the olive and tightened up just a bit and hey presto never a problem since!

people see the thread on a compression and presume that is the joint, that only pushes the olive against the pipe and fitting,t he easier it is to tighten the better fixing you will get

axzed said:
that is the overhauled replacement stopcock and after many attempts, using ptfe & boss, i cannot stop the leak from below the lower nut.
That's what my whole query is about.
Is it a union, not olives and if so, where do i pack it, as i have tried behind the union/olive?
I can't back off the nut enough to see it.
Are more turns of ptfe counter productive?

no ptfe on the thread if olive or union

pete m l · Mar 16, 2010

sounds like if you have old lead mains then its time to run a new plastic main complete from the road and do a proper job rather than keep trying to bodge it up

fuzzy · Mar 16, 2010

pete m l said:
sounds like if you have old lead mains then its time to run a new plastic main complete from the road and do a proper job rather than keep trying to bodge it up

stop spoiling our fun!

pete m l · Mar 16, 2010

oh I forgot this was a fun site try putting a hose pipe and jubilee clip on that will stop the leak

axzed · Mar 16, 2010

Thanks all.
I could just move house too.
"my whole query is about.
Is it a union, not an olive and if so, where do i pack it, as i have tried behind the union/olive?
I can't back off the nut enough to see what it is."
Early on in this posting I was told that as it is a stopcock, it can't be an olive, but a union & maybe a leather washer!
Well, I guess I can deduce from all your references to olives that this aint necessarily true.
I initially connected with minimal PTF but later noticed lots of it already behind the olive/union that I tweezered out & later back in.

moony · Mar 16, 2010

mate youve tried most things a diyer would, as a professional (i think) haha, i would dig out the hole, explore the pipe work a bit deeper down, if lead then use a lead lock on a fresh piece of lead, run 15mm up out of hole and fit a new stop tap. You can mess around with the olive, union or pipework all you want and may find you seal it, but this is the incoming mains and ive seen too much damage to property from poorly fitted stop tap or lead lock to warrent you risking this.

its a simple job for a professional, prob cost no more than 60-80 quid and it would come with piece of mind and a more suitably located stop tap. I dont know how much time you,ve spent but i would certainly think of getting hold of someone who can come and have a proper look at it.

if its a olive and youve packed it out with ptfe and its still leaking, then there could be a fault with the fitting requiring a new one to be fitted - the lads have tried to help on here but its not as easy as saying do this do that and bobs your uncle. hence the 4 year training required.

WaterTight · Mar 16, 2010

The photo is quite unclear, is the problem area the side furthest away from us? With what looks like bubbles above the nut? It looks like there's a bit of 22mm copper coming out the concrete, then a reducer to 15mm, then a very small bit of 15mm, then your problem compression nut.

There are any number of possible problems causing the poor seal here.

The pipe might be kinked from over-tightening or being pulled about.
The PTFE might be applied poorly and/or wrongly.
The nut might not be tight enough or be too tight.
The pipe might not be inserted fully into the tap body (unlikely to cause leak by nut but who knows when it's so difficult to see)
There's too little room to get tools in (tweezers aren't used by plumbers) and therefore properly gauge tightness.
There's not enough "play" in the pipe so everything sits flat.
The thread on the nut is buggered.
There is grit or gunk in the assembly preventing a seal.

I'd say the two important advisory things to take from this thread are:

1. Don't take chances, it's your internal stopcock. Mains pressure water meets your house with a unsealed nut inbetween. It's needs sorting properly.

2. A decent plumber not intent on a quick fix for cash will almost certainly begin by making the hole bigger. So should you. If you can't, call a plumber.

However....If you are unable to afford this, convinced you can do it yourself or simply cannot make the hole bigger then this is what I suggest:

1. Remove stopcock again. Clean all the boss-white off.

2. Pull back the nut and clean off all the PTFE, boss-white, grit, dirt you can. Do same for pipe. Pull forward and back while cleaning. Get some damp rag in there and have a scrub. Use some wire wool on the copper. Dry it all, have a look with a flash-light and then do it all again. But gently.

3. Apply up to 7 turns of PTFE. Apply it so it lies flat over the olive and turns round the pipe in the same direction that the nut will when being tightened.

4. Put stopcock back on. The olive should meet the end of the stopcock body. Re-tighten the nut. Tighten to a good degree. To about when you're grimacing a little, but not too much.

5. Does it still Leak? Remove stopcock again and using a junior hack-saw, hack-saw blade or olive-puller, remove the olive from the pipe. Put on a new one. Repeat 3 and 4.

6. Still leaks? Then you will need fresh pipe to work on and the hole has to become bigger.

pete m l · Mar 17, 2010

well said q-plumb i have been in the trade 43 years hence my reply of renew the entire main with plastic from the main stopcock,I have seen to many DIY cock ups and to many floods and devistated properties and people. Also it is now classed as detrimental to your health to have any lead pipework in or supplying your property
hope someone takes note of the advice given
Pete

axzed · Mar 17, 2010

Hi, Thanks WT for your kind consideration in providing an eloquent, methodical and exhaustive reply.

Yes, the lower nut. I also referred to and complied with the flow direction arrow.

There's too little room to get tools in (tweezers aren't used by plumbers)
I needed tweezers to remove & replace the PTFE behind the olive/union flange as there is too little room to lower the nut down the pipe for reasonable access. I tried a power chisel but it didn't help. lol (see previous post)

There's not enough "play" in the pipe so everything sits flat. Huh?

2. A decent plumber not intent on a quick fix for cash will almost certainly begin by making the hole bigger. So should you.
So, I guess the guy who installed it was off "Rogue Traders"?

1. Remove stopcock again. Clean all the boss-white off. Did that.

2. Pull back the nut and clean off all the PTFE, boss-white, grit, dirt you can. Do same for pipe. Pull forward and back while cleaning. Get some damp rag in there and have a scrub. Use some wire wool on the copper. Dry it all, have a look with a flash-light and then do it all again. But gently. See above - no access.

3. Apply up to 7 turns of PTFE. Apply it so it lies flat over the olive and turns round the pipe in the same direction that the nut will when being tightened. I recognised the wrap direction imperative. 7 turns contradicts previous posting advice.

4. Put stopcock back on. The olive should meet the end of the stopcock body. Re-tighten the nut. Tighten to a good degree. To about when you're grimacing a little, but not too much. I'm grimacing already. Depends on your 'grimace threshold' really.
Seriously, PLEASE, do I discount a previous posting correction that this is not an olive, but a union flange?
If not, then this surely demands a different approach.
Anyway, I am about to try again, regardless.
cheers.
Thanks

pete m l · Mar 17, 2010

it could have been a kingsley fitting at first

axzed · Mar 18, 2010

Hi again,
It is an olive.
The pipe below the olive is split!
I am going to solder a short extension on it once I find my propane torch.
Is it a leadloc?
If so, I am concerned about heat damage to the seal when sweating the joint.
Should I excavate and expose it?
Any info/tips gratefully appreciated.

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