mick
Member
Is there an easy way to judge when an olive-type compression joint (gas) has been tightened enough, but not too much?
Gas compression joint
- Thread starter mick
- Start date
Freebee
Well-known member
the short answer is when it does not leak anymore.
Cut the tube so that there is sufficient bare tube showing past the olive, do not fit the olive right on the end of the tube, ensure the cut tube is cut square if you have use a pipe cutter even for small bore, have a dry run at making the joint by hand before you prepare to tighten.
The fact is the joint has to be tightened quite sympatheticaly, with the correct size spanners, firstly assemble by hand to hand tight, then apply the spanners and nip the joint, test under pressure with soapy water, some may apply just a smear of hydraulic seal or jointing compound but it should not really be necessary.
If you strip the joint the olive should be tight on the tube unable to move but not so tight that it has deformed the tube. Its a matter of practice really
Cut the tube so that there is sufficient bare tube showing past the olive, do not fit the olive right on the end of the tube, ensure the cut tube is cut square if you have use a pipe cutter even for small bore, have a dry run at making the joint by hand before you prepare to tighten.
The fact is the joint has to be tightened quite sympatheticaly, with the correct size spanners, firstly assemble by hand to hand tight, then apply the spanners and nip the joint, test under pressure with soapy water, some may apply just a smear of hydraulic seal or jointing compound but it should not really be necessary.
If you strip the joint the olive should be tight on the tube unable to move but not so tight that it has deformed the tube. Its a matter of practice really
mithril
Member
Hi Mick
errrrr probably but I dont know what it is, however . . . .
I've re-plumbed my gas system and installed a gas bubble device which shows if I have a leak. So assuming I do not tighten the olives enough then the bubble device shows a leak. If no leak then the olives are ight enough.
When I was in E Germany a local "expert" came aboard and tightemed the olives until the 8mm pipe looked like 5mm at the joint, I'm convinced he had no idea and so simply leaned on the spanner. /forums/images/graemlins/mad.gif
Good luck, and like you, I'll watch for the authorititave answer to come in. /forums/images/graemlins/smile.gif
Check my Travelog for the details of my fuel (and gas) problems. /forums/images/graemlins/mad.gif
errrrr probably but I dont know what it is, however . . . .
I've re-plumbed my gas system and installed a gas bubble device which shows if I have a leak. So assuming I do not tighten the olives enough then the bubble device shows a leak. If no leak then the olives are ight enough.
When I was in E Germany a local "expert" came aboard and tightemed the olives until the 8mm pipe looked like 5mm at the joint, I'm convinced he had no idea and so simply leaned on the spanner. /forums/images/graemlins/mad.gif
Good luck, and like you, I'll watch for the authorititave answer to come in. /forums/images/graemlins/smile.gif
Check my Travelog for the details of my fuel (and gas) problems. /forums/images/graemlins/mad.gif
catmandoo
Active member
You can get a bottle of gas tester soapy solution from calor. Suggest when tightening you make sure that pipe is firmly pushed home at each connection and do not over tighten otherwise you will distort tube . If unsure suggest you practice on a few bits of scrap pipe and then take apart . you will soon see if olive has bitten into pipe wll or not you can always get extra olive s for pence
KREW2
Well-known member
Hi
the only way you can be sure you dont have any leaks is to get a gas fitter to put a water guage on your system, I believe insurance companies are now starting to insist on this, and want to see a certificate from a marine corgi registered fitter, why they differ from a caravan or domestic fitter I dont know, but peace of mind is not such a bad thing
K W
the only way you can be sure you dont have any leaks is to get a gas fitter to put a water guage on your system, I believe insurance companies are now starting to insist on this, and want to see a certificate from a marine corgi registered fitter, why they differ from a caravan or domestic fitter I dont know, but peace of mind is not such a bad thing
K W
Avocet
Well-known member
I'm not sure that a small amount of deformation of the copper pipe is a bad thing. Copper really is very soft! All mine are a bit deformed and seem to work fine. It's hard to quantify a "bit" but on one occasion I ended up cutting off several olives and if I squint down the inside of the pipe, I can see a slight change in bore under the olives.
Incidentally, I replaced some "T" pieces a while back and was a bit surprised when, a week later, my bubble detector showed a leak. To my horror, one of the new nuts on the "T" piece had cracked. I replaced it and the following week, two more had cracked!!! Needless to say, I replaced all the "new" "T" pieces!
Incidentally, I replaced some "T" pieces a while back and was a bit surprised when, a week later, my bubble detector showed a leak. To my horror, one of the new nuts on the "T" piece had cracked. I replaced it and the following week, two more had cracked!!! Needless to say, I replaced all the "new" "T" pieces!
Porthandbuoy
Well-known member
One and a quarter turns from hand tight.
itsonlymoney
New member
Simple answer....Experience.
Incidentally do not use soapy water as a leak test. Recent reg's state that the detergent can effectively corode the copper over a period of time, use an over the counter approved gas leak spray. I would also point out that just because after tightening there is no leak apparent, if the joint is not "made" correctly a leak could indeed develop later due to movement and expansion / contraction of pipe and fitting.
As a CORGI registerd business I should point out that anyone carrying out work on a gas related installation who is a "non competent" person ie. not CORGI registerd and not CITB trained and approved is breaking the law. Yes it does include work on your own premises, boat or caravan.
Not getting heavy just passing on a relevent point worth knowing.
Regards - Ian
Incidentally do not use soapy water as a leak test. Recent reg's state that the detergent can effectively corode the copper over a period of time, use an over the counter approved gas leak spray. I would also point out that just because after tightening there is no leak apparent, if the joint is not "made" correctly a leak could indeed develop later due to movement and expansion / contraction of pipe and fitting.
As a CORGI registerd business I should point out that anyone carrying out work on a gas related installation who is a "non competent" person ie. not CORGI registerd and not CITB trained and approved is breaking the law. Yes it does include work on your own premises, boat or caravan.
Not getting heavy just passing on a relevent point worth knowing.
Regards - Ian
richardandtracy
New member
I've got a little feeling that you're getting 'Competent' and 'Corgi Registered' confused - they are not precisely the same thing. You can be 'Competent' without being 'Corgi' Registered, you just can't do business without being 'Corgi Registered'.
Some of the work I've seen by 'Corgi Registered' people cannot be confused with 'Competent' in any way, shape or form.
Unfortunately.
Regards
Richard.
Some of the work I've seen by 'Corgi Registered' people cannot be confused with 'Competent' in any way, shape or form.
Unfortunately.
Regards
Richard.
LittleShip
New member
Competent means you can fit it ........Corgi means you can turn it on?? /forums/images/graemlins/smile.gif
richardandtracy
New member
More like
'Competent':- You can fit.
'Corgi':- You can charge.
Regards
Richard.
'Competent':- You can fit.
'Corgi':- You can charge.
Regards
Richard.
Anwen
Member
If you use compression fittings from Swagelok, then there is a feeler gauge which should be able to be inserted between the back of the nut and the body of the fitting. This takes any guess work out of making the joint. Swagelok fittings are industrial quality, and are suitable for hydrogen use. Consequently, they are expensive, but definitely marine quality!
30boat
N/A
This is probably a bit off this particular subject but I think that gas is too dangerous in a boat.Or anywhere else for that matter.
I got rid of my old Flavell Vanessa (up for grabs if anyone wants it) and installed a Wallas Parafin hob.If that one ever goes seriously wrong I'll get another one regardless of cost.I know of at least four boats that blew up and have read enough horror stories to put me off gas forever.
I got rid of my old Flavell Vanessa (up for grabs if anyone wants it) and installed a Wallas Parafin hob.If that one ever goes seriously wrong I'll get another one regardless of cost.I know of at least four boats that blew up and have read enough horror stories to put me off gas forever.
KREW2
Well-known member
At least if I blow up I'll be certified
regards KW
regards KW