Do I need to paste/tape this connection?

[Mr. Clueless]

I always thought that it needed to be pasted or taped on the left side (the one coming out of the floor), but then i'm a know-nothing at this stuff so i'm quite happy to hold my hand up & say i'm wrong.

Reason i ask is because we had new rads installed downstairs by 2 different plumbers. They've had to be removed for decorating & when i removed them I noticed none of them had any paste or tape on these ends. The other end being the TRVs & they didn't have paste or tape on those ends either.

If it was just one plumber then i would've thought maybe he forgot or was just being slack, but two plumbers? I'm either quite unlucky in my selection of plumbers or i'm wrong.

Now i've put them back on the walls & we'll be getting carpets put in, i don't want to connect them up slapdash style so i'll ask here first.

 

[Dan Robinson]

You don't need anything on the olive. Only joint that does in your picture is the insert of the radiator.

 

[Dan Robinson]

It fills most of us with dread when we see tape on olives.

 

[Mr. Clueless]

So to just clarify (sorry)...
that part that is sticking out of the radiator (sorry you're going to have to forgive my ignorance on terminology) with the nut on it - this needs tape/paste on the end that actually connects in to the radiator...

but to connect the bit coming out of the floor to the part that is sticking out of the radiator, i don't need any tape or paste on that connection at all?


I know it probably gives a good giggle to those who are in the know, but i'll take it on the chin

 

[Dan Robinson]

Yes

 

[Mr. Clueless]

Everything on & everything tightened.

Predictably out of 6 connections, 1 had a very slow leak coming from i think just where the nut from the radiator end connects to the valve coming from the floor. It was already quite tight but i tightened it a midge more. Hopefully that's fixed it.

I re-pressurized the system & turned the heating on. Fingers crossed no leaks.



Just another question though if you don't mind.....

the (lockshield?) end. I can't remember the positioning of it (the bit you tighten with the spanner) before i totally closed it off. I think i didn't have to move it too far to tighten it up but i don't know for sure.

Now i can keep loosening it off all day long but i guess this isn't such a good idea? I've had to slacken it off a bit to get the water flowing so the rads heat up & see if there's any leaks, but since i can't remember the positioning of it too good, what do you suggest (short of saying name yer price to someone)?

 

[Mr. Clueless]

Bugger. It's still leaking

Put a tissue underneath & while the actual metal connection is dry, or at least seems it, the tissue underneath is wet.

Looks like i'm going to have to call someone out after all.

 

[ianmcd]

Take a pic of what is leaking and post it as your description is very vague

 

[Jackrae]

In response to your original query, I always put a slight smear of jointing compound on compression couplings during assembly. Whilst olives are supposed to provide a tight mechanical joint a the smear of compound always offers the opportunity of sealing off any imperfections in components.

With an olive joint that's been previously made and disassembled there is always the possibility of a leak on reassembly simply because the olive is already 'formed' to suit what was the fitting's original shape and further tightening usually just causes 'waisting' of the tubing rather than 'reforming' of the olive.

The use of tape on olive based fittings is, in my opinion, a sign of a crap job. Although teflon tape is now almost universally used as a 'sealing' product it certainly wasn't developed as such. It's orignal intent was simply as a lubricant for tapered fittings, where metal-to-metal was the method of sealing. However in the interveaning 50 years or so, techniques and skills have changed - not always for the better. Many industries still prohibit its use on fittings as it can plastically creep into the system during tightening and cause 'downstream' problems

 

[Mr. Clueless]

Take a pic of what is leaking and post it as your description is very vague

I'm pointing at the leak point.

I have a plumb tray underneath now with a tissue in. I turned the heating back on for 30mins & turned it off about 15mins ago.

The tray & tissue is currently dry.

If it was going to leak, at what point would you expect it to leak (or could it be anyones guess?) - when the system is hot, when it's cooled down, or just anything in between depending on how it feels?


Jackrae - If i get you right then you're saying that putting in tape or paste from the outset (where i'm pointing) is a bad thing, but that once you've removed & reconnected then you may have to put a bit because you may get what i'm getting now?


Also i don't know how tight you're supposed to tighten these things. Obviously nobody wants any leaks so i guessed fairly tight. I YouTube'd some videos & the old fella seemed to be putting some decent force in to it so i figured go quite tight. Don't worry, i didn't bend the piping to the left of my finger. Been there done that, but thankfully not this time

 

[ianmcd]

undo the nut again and wrap some PTFE around the olive then tighten it back up and it will be fine

 

[Mr. Clueless]

I'll have a do at that tomorrow, thanks.

To avoid any tears i'm going to have to ask....

1) PTFE tape, do you wrap the same way the nut would tighten or opposite? So looking at the photo above, to i wrap in to the wall / the direction i am pointing or away from it?

I googled to find all manner of answers which is why i'm asking. Wrap this way, wrap that way. Start at the connection end & work left, start at the left & work to the connection. Ok for you plumbers who can pick the right from the wrong but not good for someone who isn't sure Though please don't say 'with/against threads' as i didn't get that one


2) Is there any way i can undo that nut without having to drain off that full radiator? Or is that unavoidable?

 

[ianmcd]

just close both valves at either end and put a towel under the joint , you will get some water dripping out, you are wrapping the olive , the ring that is compressed onto the pipe not any threads , it wont matter which direction you wrap it , I always do it clockwise but it doesnt matter , only wrap it say 4 or 5 times then connect the pipes back up and you will be fine

 

[Mr. Clueless]

I remembered after posting that that I'll need to drain the system anyway after putting x400 in it so that bit doesn't matter.

Good job you said that. I had to google images 'plumbing olive' to see what it is - that ring part. I would've just wrapped the threads of the bit that connects in to the radiator if you hadn't said

 

[Mr. Clueless]

This is a real strange one, to me at least.

I wasn't going to do anything until the weekend anyway. My wife & I have tea at my mothers on a Monday so as she was passing the house she called in, checked the boiler (pressure hadn't dropped since this morning) & turned the heating on. Oh - no leaks from there either.

Get home a few hours later - check everything. Boiler is now at 1.5 bar (up from 1.0 bar). All rads are hot .... & still no leaks.

Turn the heating off & check once again as it cools down ... still no leaks.



So unless there was a wet patch on the floor yesterday that i hadn't wiped up, or something else that i thought i'd taken care of which i actually missed then i don't know how to explain how it'd leak one minute but not the next.

It was certainly leaking at the very start - this isn't the leak i'm talking about. I saw that myself. But then i gave it another turn as i tightened it a bit more. It was after this part that i thought it had stopped but then later on i found the tissue underneath was wet. So as i say, unless i hadn't mopped everything up from the initial leak as well as i thought i had.





Would you still undo & re-tighten or would you leave it now as it appears to not actually be leaking?