Over time it can develop leaks if it is flexed enough. Check your local code though. Some used to say no flex except for stoves, others now want flex because of potential seismic movement that could break regular pipe joints. .
If you can get away with it where you are, and you don't screw it up, more power to you. Can't do it here if you are getting an inspection, so I just use pipe dope, even when I'm NOT getting an inspection. Hate to have someone else working on it later, needing an inspection, and having it failed and come back on me. Ain't going to happen, buddy. Do tit once, do it right.
Used to also be you could not use galvanized fitting on NG lines here
- but now you CAN.. Some inspectors still don't like it, but it is now legal in some areas. It's possible the yellow tape MAY pass here now too, but when my furnace was replaced about 3 years ago, it was still not allowed - the whole job was done with pipe dope - just like the water heater 8 or more years ago. The guy doing the furnace inspection said if there was ANY teflon tape visible he could not turn the gas back on - period - end of story.
It's been a few decades but I've fit miles of pipe when I worked in chemical plants back in the 70s. Threaded pipe up to 2" and flanged up to
12". IMHO using both tape and dope would be a waste of time. Applied properly and installed correctly, neither will leak.I like BLACK iron pipe BECAUSE it is visibly different THAN water pipe. So, YOU can tell by JUST looking which ARE which.
I've ALSO found that the LOCAL inspector may be RIGHT or WRONG, but on some THING like teflon tape, IT IS easier to do it like the local INSPECTOR wishes. NATURAL gas is low enough PRESSURE that either ONE is likely to SEAL.
Up here they really like it if you paint the gas pipes yellow. IF there is also galvanized water piping in the building.
Other than industrial/commercial sprinkler systems, galvanized water piping is pretty much extinct around here.
Au Contraire, mes amis - I very often mention "up here in Ontario" or other references to my location.
Waterloo Ontario - home of the RIM Blackberry, Open Text, Sandvine Systems, MKS, and a slew of other world renouned technology companies.
Oh, gosh. That would be useful for us American readers to know. Of course, we all think everyone who posts to AHR lives in USA. Cheerio!
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.