Gas PTFE tape vs.water PTFE tape

[namsag]

Tonyboy where did i say it Caused explosions. That was something Onetap said i guy said to him.
What i said is once the ptfe has deteroited the joint is then loose and the resulting gas leak could then b ecome dangerous

Onetap i will put it to you really simply why does it just not say wrap loads of normal ptfe around joint to simulate thicker gas grade tape
And why if you done this and there is no leak it would be a FAIL in ACS exam.

I have tins of paste that The contents look exactly the same but would i use them both on LPG, no, why because it says so on the tin

Same as the 2 rubber cooker flexes they look exactly the same and and if i fitted a NG flex onto a LPG cooker it would work perfect and be perfectly sound with no leaks at all for probably about a year.

But all the time the LPG would be reacting with the rubber in the flex and what was a previously sound installation would then be pouring gas out and becoming a potentially explosive condition.
Have i done independent chemical analysis on these NO i listen to what the manufacturers of these products say and results that come from independent testing houses.

You seem to have a big problem with such a basic concept

 

[tonybhoy]

Chill big boy I was being sarcky

 

[namsag]

.its a monday .

 

[tonybhoy]

.its a monday .

I know great eh?

 

[namsag]

Yep mondays are for recovery from multiple weekend hangovers . Its great being your own boss
Nipped out looked at 3 wee jobs and soon off to laze in the sauna after a bit of gym workout.
Of course i have been busy all day darling what do you take me for.

 

[ChrisR]

namsag wrote:
Ok here is one that is just as basic which joint should not be done with PTFE gas or otherwise

CHrisR:
There's nothing to say you can't use PTFE on a long screw

namsag

Chrisr as a ACS instructor you should know on the lock nut side it is hemp and paste and that is an ACS question as you are moving nuts up and down the pipe and ptfe would not be sufficent for this

The only question I know asks where you CAN use Hemp , not where you MUST. BS says the same. Good, innit!
Maybe it's written somewhere, IGE maybe. ANyone know?

Never tried L55 on a long screw but I expect it's fine.
I've seen PTFE tested and apparently it was OK.
I don't think my llife will be incomplete for the lack of touching another...

 

[IJWS15]

Just to lob a stone into the pond that seems to be settling. . . .

I am not Corgi registered but have done my own gas work.

Wasn't the reason that over enthusiastic use of thin PTFE tape can cause small pieces of tape to come away INSIDE the pipe. Once there gas flow can move it around the system and it can cause valves to jam. This resulted in a total ban of PTFE on gas a few years ago, thicker heavier tape probably stops this happening.

Did not know that there was a thicker tape available - do now (some of you will be thinking "Damn - too much information for the DIY losers - should have had the PTFE thread in the secret forum" ).

BTW and AFAIK PTFE is totally inert and does not react with anything including jointing paste. Possibly something to do with the F in PTFE - Flourine is chemically very reactive so difficult for anything else to displace.

On Paste and PTFE the presence of the paste may just hamper sealing by the PTFE and vice-versa.

 

[namsag]

Chris r . The wording in the book i have is blah blah blah.
To make the joint,the coupler is run off the parallel thread and onto the pipe thread. Because there is no seal between the coupler and the long screw threads a soft hemp washer or grommet is covered in jointing compound and compressed between the coupler and the backnut. These joints are only suitable for low pressure supplies.
Pipe threads where pressure tight joints are not made on the threads should comply with bs2779: 1986 . They are also of whitworth form and the BSfollows the ISO 228/1 and 228/2 recommendations.

 

[Agile]

Flourine is chemically very reactive so difficult for anything else to displace.

That may be something to do with bakers?

I expect you mean Fluorine with the symbol "F".

I vaguely remember that even gas PTFE can only be used on small pipe sizes, perhaps below 1½" ?

I also remember that gas PTFE has to be used with ( at least ? ) a 50% overlap.

Tony

 

[ChrisR]

Chris r . The wording in the book i have is blah blah blah.

Then get a better book! There should be Standard documents covering it.

To make the joint,the coupler is run off the parallel thread and onto the pipe thread. Because there is no seal between the coupler and the long screw threads a soft hemp washer or grommet is covered in jointing compound and compressed between the coupler and the backnut. These joints are only suitable for low pressure supplies.

Is that the law according to namsag, or from a Standard?

BS2779 is withdrawn and only covers the threads, not how they're sealed.

IOW, where does it say you have to use hemp?

 

[namsag]

Nope its fom a BG training manual that takes everything from the standards.
And the initial blah blah bit was describing what a long screw is for but diddnt think i needed to put that

 

[GforceJames]

PTFE is for girls, long live Loctite 55.

James

 

[Norcon]

Seems as though I can keep using normal ptfe for my diy gas exploits as the two are the same according to Onetaps link.
Apart from the thickness that is.
Happy Days......

 

[tonybhoy]

PTFE is for girls, long live Loctite 55.

James

How is this stuff for taking fittings apart after it's been on a while?

Think I'll be buying some,this thread (sorry) has been iluminating

 

[DCPlumbing]

There's only one way to settle this... Fi i i i i i i i ight!