Copper pipe wall thickness

[noonespecial]

You don't use compression fittings in lieu of getting the correct pipework for the job.

Well, lots of DIYers do, and what on earth is wrong with that?

I would say you are right for water pipework and DIYers. They do the job, are not that difficult to install and safer than gas torch. They are more expensive and bulkier. BUT I READ HIS POST THAT HE IS PROPOSING TO INSTALL GAS PIPEWORK - If it is just one intermediate compression joint on gas then fine. Re-reading the post the guy does not make it clear if it is water or gas.

...PTFE And you don't use that in compression joints

Really? Why not? Perhaps you don't use it, but that doesn't make it wrong, so why do you imply that there is a general rule when there's no such thing? Perhaps to maintain some ridiculous clique of which you think you are a part?.

Well I have to hold my hands up to your practical experience on making joints as I do not install them and have really very little experience in doing so. I know a lot of plumbers use PTFE tape on the screwed sections and jointing compound and also PTFE tape on the olive rings. But that all contravenes manufacturers recommendations and also anyway the joints are designed to rely on a mechanical metal to metal contact. I know tape and compound can overcome some minor leakage problems. But I have investigated quite a few severe water damage cases and seen probably hundreds of minor water leaks which has been due to excessive PTFE tape being used (not all by DIYers) and also unfortunately one death from LPG which was done by the same unfortunate DIYer. AS a result of my experiences no plumber that I employ will use PTFE tape or jointing compound on compression joints. And really it is not a problem.

I think you have too much to learn before you should attempt to install pipework.

I disagree - the guy is willing to learn, has come to the right place (although receive many unhelpful replies), and, with some experimentation, there's no reason why he can't make a start. We all began somewhere...

OK if it is water BUT AS I SAID ABOVE I READ THE POST THAT IT IS GAS HE IS PROPOSING TO INSTALL.

Above very long winded so to summerise I would say:

If it is water pipework guy is doing then fine and I agree there is no technical reason why he cannot use compression fittings. PTFE tape should not be used on the joints.

IF IT IS GAS PIPEWORK - no not until he knows what he is doing, has adequate experience and is competent.

 

[Softus]

Re-reading the post the guy does not make it clear if it is water or gas.

I concur, therefore you might have a cause for concern - it didn't occur to me that it might be for gas. However, he was not encouraged to bend the pipe, as he wanted to do. Quite the reverse in fact.

If you want to know whether or not he's doing gas work, then why guess? Why not just ask him?

AS a result of my experiences no plumber that I employ will use PTFE tape or jointing compound on compression joints. And really it is not a problem.

On gas pipe joints I would agree with you. On the threads of compression couplings I would agree with you. However, there are plenty of nut and olive joints, tap connector joints, cylinder boss joints, and many more types of joints, all of which will readily leak water that is at high pressure without the use of either jointing compound (which I don't favour) or PTFE tape (which I do).

OK if it is water BUT AS I SAID ABOVE I READ THE POST THAT IT IS GAS HE IS PROPOSING TO INSTALL.

I know you said it above, within your own reply, but you're shouting at me as though I haven't listened, whereas I hadn't had the chance to listen. Bizarre.

If it is water pipework guy is doing then fine and I agree there is no technical reason why he cannot use compression fittings. PTFE tape should not be used on the joints.

Utter nonsense, especially since you've said that this belief is not based on practical experience.

IF IT IS GAS PIPEWORK - no not until he knows what he is doing, has adequate experience and is competent.

An excellent illustration of tautology - the law requires him only to be "competent".

 

[noonespecial]

If you want to know whether or not he's doing gas work, then why guess? Why not just ask him?

Agreed - you thought it was water, I thought it was gas and we still don not know. f49h please clarify. Then you will get the advice which you are after.

On the threads of compression couplings I would agree with you. However, there are plenty of nut and olive joints, tap connector joints, cylinder boss joints, and many more types of joints, all of which will readily leak water that is at high pressure without the use of either jointing compound (which I don't favour) or PTFE tape (which I do).

Softus this is something I think we will diasgree with. You know what you are doing, you have done it probably for years and it works for you-on that basis therefore who can or should argue with what you do. There is a difference though between a compression fitting and a boss, etc in so much as there is releince upon two processes to make the joint eg tightening up the screwed thread and pushing down upon the olive. And I would assume a boss, etc was originally intended years ago for a jointing material to be used.

OK if it is water BUT AS I SAID ABOVE I READ THE POST THAT IT IS GAS HE IS PROPOSING TO INSTALL.

.

No sorry did not mean it like that, did not mean to 'shout' just to emphasis that I thought it was gas. Should have used lower case as I am sure you can read lower case as good as upper case, unless your eyes are getting like mine

If it is water pipework guy is doing then fine and I agree there is no technical reason why he cannot use compression fittings. PTFE tape should not be used on the joints.

Utter nonsense, especially since you've said that this belief is not based on practical experience.

I think we will disagree and leave it at that-what I meant though by practical experience is that throughout my 35 odd years in the industry I have only actually made a handful of compression joints up but I have inspected must be thousands of suspect/failed joints.

competent.

= even HSE cannot or will not define competent and they are the ones requiring such people to do the work.

 

[Softus]

Softus this is something I think we will diasgree with. You know what you are doing, you have done it probably for years and it works for you-on that basis therefore who can or should argue with what you do. There is a difference though between a compression fitting and a boss, etc in so much as there is releince upon two processes to make the joint eg tightening up the screwed thread and pushing down upon the olive. And I would assume a boss, etc was originally intended years ago for a jointing material to be used.

I appreciate that there is a distinction in the designed sealing method, but then there are tapered threads...

...unless your eyes are getting like mine

I'm afraid that they are

I think we will disagree and leave it at that-what I meant though by practical experience is that throughout my 35 odd years in the industry I have only actually made a handful of compression joints up but I have inspected must be thousands of suspect/failed joints.

Well, OK.

 

[f49h]

I dont think a question about bending pipe is technical.
A yes or no whould have done.

 

[Softus]

I dont think a question about bending pipe is technical.
A yes or no whould have done.

Really. Well then, would you give an example of a question about plumbing and central heating that you do consider to be "technical"?

 

[f49h]

What size of a boiler in BTU's do you need for 10 radaitors
How do you work out the size of radiators for a given room size taking into account of the number of windows.
How do you calculate the heat loss.
What is the maximum heat loss in a radiator when you balance them.
How many Pizza's can you fit in a trumpet.
Why is abbreviation such a long word.
Blah blah blah blah

 

[Nige F]

.
A yes or no whould have done.

Yes

 

[Softus]

What size of a boiler in BTU's do you need for 10 radaitors
How do you work out the size of radiators for a given room size taking into account of the number of windows.
How do you calculate the heat loss.
What is the maximum heat loss in a radiator when you balance them.
How many Pizza's can you fit in a trumpet.
Why is abbreviation such a long word.
Blah blah blah blah

...which all goes to demonstrate why you're the layman who's having to ask for free technical information.

However, the pizza thing is extremely amusing - I'll give you that.

 

[noonespecial]

Why is abbreviation such a long word.

Don't know but it is not the longest word.


You have elastic which stretches on and on

You also have smiles - which has a mile between the first and last letter.

 

[f49h]

Good lad your starting to chill out.
See ya later

 

[chr15]

Just out of interest,what is the problem with jointing compound on compression joints?

 

[croydoncorgi]

The problem with PTFE on compression joints is where it ends up. If it stays between the 'compression cones' and the olive - all well and good - it MIGHT make the diference betwen a leak and no leak. OTOH - the manufacturers and designers INTENDED the compression joint NOT to need additional sealing apart from the compression of the olive onto the pipe and the tight fit betwen olive and cone sections. The other problem is that there is NO practical way to seal the hole where the pipe comes through the nut, so if fluid has got past the olive it WILL come out of the hole in the nut; so tape on the threads on the body of the joint is ALWAYS a waste of time.

Jointing compounds are a different matter. Once again, it's a question of what the designer intended. IMHO, the main benefit of Hawk White or similar is that is helps lubricate the threads and the olive so it's easier to judge when the joint is tight enough without having to consider the effort needed to overcome friction as it tightens.

 

[Softus]

...there is NO practical way to seal the hole where the pipe comes through the nut, so if fluid has got past the olive it WILL come out of the hole in the nut; so tape on the threads on the body of the joint is ALWAYS a waste of time.

Whilst I agree that tape on the these threads is a waste of time, I don't agree that there's no practical way to seal the olive/pipe junction. Both Hawk/Boss White and PTFE tape will do it. IMHO, the 'White' is capable of being washed away, whist the tape isn't, hence I prefer either the latter or else nothing at all.

Jointing compounds are a different matter. Once again, it's a question of what the designer intended. IMHO, the main benefit of Hawk White or similar is that is helps lubricate the threads and the olive so it's easier to judge when the joint is tight enough without having to consider the effort needed to overcome friction as it tightens.

Brass is an alloy that self-lubricates, hence the threads don't need lubircating. Hawk/Boss White just makes a mess and can be eroded by the passing of water. Personally, I have no trouble judging the effort needed - if you're unsure then I seem to recall that the MI specify the correct torque.

It comes down to whatever you're used to and what you find to be reliable. There is no perfect solution, although we each believe our own method to be the best!

 

[Nige F]

. OTOH - the manufacturers and designers INTENDED the compression joint NOT to need additional sealing apart from the compression of the olive onto the pipe and the tight fit betwen olive and cone sections. .

.....The Road to Hell is paved with good intentions.............and when the comp. fittings were manufactured in Britain with copper olives inside.......I would have agreed.............now they come from the Yuk Fu........manuf. co. somewhere in China.........and as a Plumbers` merchant once said to me Re. buying policies........."Cheapest on the day".............Brass olives inside I just apply a smear of LS-X and Think of England