For those who were following this thread, here's a new development and
probably the final answer as to what the silver fitting is:

Earlier, I had written,


"They (the gas company) came out today and I asked them what the fitting is.
They said it is
called a "posilock" fitting. It is used because the old steel gas lines
that came into buildings are no longer used for gas supply. Instead, the
steel pipe is now used as a conduit. Inside the steel conduit is a plastic
gas supply line that comes in from the street. The posilock fitting
connects the plastic gas supply line to the gas line that is inside the
building that goes to the meter."



Later, I wrote,



"The first street 90 was taken off, but the silver color
fitting and the straight brown fitting that it is attached to were left in
place. I was not there, but the person doing the work looked inside the
supply pipe coming through the wall. He said it is nothing but a hollow
steel pipe -- no plastic gas line inside, etc.



So, the person who told me that the silver fitting was a "posilock" that
connects to a plastic gas supply line that is inside the steel pipe was
mistaken."



Well, the new develoment is that we took the street 90 off again, and this
time, I personally looked inside the pipe rather than relying on what the
person who was doing the work before said he saw when he looked inside the
pipe.



When I personally looked inside the pipe yesterday, I could see that the
other person's impression of what he saw was clearly mistaken. When I
looked in, I could see what is apparently the smooth inside of the plastic
gas line that the gas company said is inside of the 1 1/2-inch steel pipe
coming into the building. The inside is smooth and has some fine lines
running longitudinally (sp?) along the inside of the tubing; and the
diameter of what is in there is clearly smaller than the inside diameter of
a 1 1/2-inch steel pipe.



It does looks like the silver fitting and the fitting attached to that are
what adapts a plastic gas line inside the incoming steel pipe pipe to the
black iron gas piping inside building that goes to the meter. I didn't take
those two fittings apart (and I don't intend to), but I have a hunch that
the two pieces serve as a pipe ferrule fitting to secure the incoming
plastic gas line to the interior black iron gas pipe (somewhat like the
fitting diagram shown here
http://www.thepipefittings.com/pipe-ferrule.html ).



So, as far as I can tell, the gas company person who told me that the silver
fitting is a "posilock" that connects to a plastic gas supply line that is
inside the steel pipe is CORRECT.



I think that is the final answer on this one.



++++++++++++++++



RogerT wrote:
I have a gas line coming into my house through the basement wall. The line
coming looks like it is about a 1-1/4 inch pipe. The pipe
comes in, then there is a silver steel color knurled fitting, then a
regular reducer fitting, then a street 90 degree L. From there, the
piping goes up to the gas meter that is in the basement.

What I am trying to figure out is, what is that silver steel color
knurled fitting? Whatever it is, it is threaded onto the pipe that
is coming into the house and threaded into the reducer fitting.

Here are two photos:

http://i56.tinypic.com/qx9kl1.jpg



http://i51.tinypic.com/15n7syh.jpg



This is in New Jersey (PSE&G is the gas company). Yes, I know I
could try calling the gas company to find out, but it is next to
impossible to get through to them on the phone, and I have already
had them out there twice because I am trying to figure a way to
relocate the meter about one foot over for remodeling. They were no
help (long story), and I didn't think to ask them while they were
there what the knurled fitting is. I have a hunch that the knurled
steel fitting is some kind of gas company tag or marker that they put
on to make sure no one has tampered with the gas line before the
meter. Does anyone know if that's correct or what that fitting is?


Thanks.