In the US, where I am. Natural gas is a low enough
presure, that the folks I work with coat the
external (male) threads with a bit of Rectorseal
#5. We do not use teflon tape on gas threads. Risk
of some of the tape flaking off, and get into the
gas valve, and create more problems.

Can't comment on the long or short ends of the
elbow. Try both -- see which works better.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"john bently" wrote in
message
...
Just replacing the kitchen gas hob for a new one.
It comes with a
right-angled pipe (an elbow), one end of which
goes into the hob and one end
into the copper supply pipe.

The *threaded* part of one end of the right-angled
pipe is about 4mm longer
than the threaded part of the other end.

Would it be the *longer* threaded part that goes
into the hob or the
*shorter* threaded part?

Since I was supplied with a rubber washer to go
into the hob connection
joint, should I use gas tape on both the threaded
ends of the right-angle
pipe. Thanks for advice.