Originally Posted By: James D Mosier This post was automatically imported from our archived forum.
Caoimh?n P. Connell,
What?!?
How about some words with those acronyms.
LEL, CGA, GCA (typo maybe?), UEL, etc.
Thanks!
bkelly2 and phinsperger,
While checking my own house for leaks I noticed that when I installed my second hot water tank 5 years ago I used white teflon tape (codes, shmodes, who needs a plumber? ) No leaks yet. Is it so important that I should re-plumb it or can I just wait until I install the third one? My tendency is to just keep it in mind for the next time.
Originally Posted By: Gary Reecher This post was automatically imported from our archived forum.
phinsperger wrote:
bkelly2 wrote:
And I do not think teflon tape is ever allowed on natural gas piping anywhere.
The white stuff - No
The yellow stuff - Yes
Well the installation instructions for gas valves, Honeywell and White Rodgers, state do not use teflon tape for pipe connections. And yes they do inspect the those warranty turnins and find teflon tape as a culpirt in valve failures.
Originally Posted By: bkelly2 This post was automatically imported from our archived forum.
James D Mosier wrote:
Caoimh?n P. Connell,
bkelly2 and phinsperger,
While checking my own house for leaks I noticed that when I installed my second hot water tank 5 years ago I used white teflon tape (codes, shmodes, who needs a plumber? ) No leaks yet. Is it so important that I should re-plumb it or can I just wait until I install the third one? My tendency is to just keep it in mind for the next time.
You should follow the local code and or monitor the tape.
The thing is when the trained craftsman finishes the plumbing they pressure test the line. Minimum is probably 2 x working pressure for 15 minutes. So let's see, 10 psig for 15 minutes using some old gauge that is laying in the back of the truck, unless they are big leaks they usually pass.
Of course your local gas authorities take precidece but if you ask anyone about it make sure they are clear about the yellow stuff that is approved for gas. They will probably will just hear "gas" and "teflon tape" and then their preprogramed answer will be no.
The color usually signifies a denser and thicker tape. Sometimes, it's just colored tape--but we'll ignore that junk from disreputable vendors.  These tapes are used for pressure fittings, particularly gas fittings, because the denser, thicker material more assuredly seals the joints. This extra assurance from the thicker, denser tape is absolutely critical with flammable and highly toxic gases like methane, propane, etc.
One argument against teflon tape is that the hair-like fray that peels away is bound to go downstream and hang up a regulator, foul a pilot orifice, hang up a diaphragm within a gas valve, get caught in an inlet screen blocking flow, etc. If yellow (denser, thicker and less likely to fray) is applied correctly (not covering the starter threads) than there is no reason why it would fray and get bunged up somewhere.
Originally Posted By: Caoimh?n P. Connell This post was automatically imported from our archived forum.
James D Mosier wrote:
What?!?
How about some words with those acronyms.
LEL, CGA, GCA (typo maybe?), UEL, etc.
See? That's what government work does to your brain...
LEL = Lower Explosion Limit. The lowest concentration of a gas in air that will support an explosion in an upward direction. e.g. 100% of the LEL for propane is given as 22,000 ppm in air; 50% of the LEL would be 11,000 ppm, etc.
CGA = Combustible Gas Analyzer (an LEL meter)
GCA = Not enough coffee
UEL = Upper Explosion Limit. The maximum concentration of a gas that can exist in air and still support an explosion in any direction; any more than this concentration, and the mixture becomes too fuel rich (insufficient oxygen to permit the repid oxidation to occur).