Compression fittings

[kozak1968]

Just about to fill 2 unvented cylinders and i check that all compression fittings are done up. I have noticed that some fittings are not as tight as when first installed. It seems that the compression fittings these days feel tight but need re-torquing. Has anyone else experienced this.

 

[Guest123]

Never known this, compression fittings should remain tightened. Again I only use Conex these days as they don't leak and have the correct slip to connect on to any brand of plastic pipe.

 

[kay-jay]

Yes!
Had this on a brand new alpha boiler. On the gas connection of all places. It was the fibre washer connection and not the olive. Me and my boss got called out a week or so after the install because of a strong smell of gas.......
Was probably about six months ago

 

[Guest123]

So it was the wssher joint that failed and not the actual compression joint with olive.

 

[kay-jay]

Yes but the principle is the same.
Screwed female onto screwed male needing re-torquing as the original tightening relaxed or slackened

 

[lame plumber]

More likely you never did it up.

 

[kay-jay]

More likely you never did it up.

Nope!

 

[lame plumber]

so why did it leak, cant have been done up properly first time

 

[kay-jay]

Suggest you reread the thread

 

[lame plumber]

just read it again, still need to tighten the nuts properly first time imho

 

[kay-jay]

Im more than capable of tightening a nut.
The point being made on this thread is that there is a mechanical failure on some fittings where the threads of m to f are not staying at the bite.
If you haven't experienced it yourself pal then that's fair enough but i seriously resent you suggesting i can't tighten a nut

 

[jam1979]

kay jay dosent tighten nuts lol funny this convo

 

[kay-jay]

I've never been into tightening nuts but I've left a few flanges on the slack side....

 

[jam1979]

lol u wish kev

 

[jam1979]

hows the toxteth job going

 

[kay-jay]

hows the toxteth job going

Way to hijack a thread Jamie!
Doing ellesmere port as well.
Flues wastes and soils in tocky but no soils in e.p but they are bungalows made of corrugated metal panels screwed to a a 3x2 frame.....no wonder they need external insulation

 

[lame plumber]

Im more than capable of tightening a nut.
The point being made on this thread is that there is a mechanical failure on some fittings where the threads of m to f are not staying at the bite.
If you haven't experienced it yourself pal then that's fair enough but i seriously resent you suggesting i can't tighten a nut

knew youd bite in the end just teasing

 

[Nostrum]

Yes I have had compressions feel like they slackened off, I always thought it was a temperature contraction thing. Fill it with cold water, or tighten up when there os still some latent heat from soldering and you can get another half a turn on it. Either that or your a bit stronger the second time around!

The gas leak above may have been the washer shrinking. Used to find lots of restrictor elbows with small leaks on them with the red fibre washer, we used to fit black replacements with the metal band and these seem to hold up better, some boilers use them as well ( Worcester I think)

 

[gassafe]

I can sometimes re-tweak the compression joints, it may be because I tighten joint whilst a joint is still hot from a nearby solder joint! I think it's down to different temperature effects, I'm paranoid about compression joints! Always rechecking joints that I know I tightened! It's crazy!

 

[GasmanxxxR1]

Tighten till they squeek!