I had to remove a gas pipe from a fire today to rotate the pipe 180 degrees.
In doing so a compacted fibre washer (?) came out and so needs to be
replaced. Is it just a normal fibre washer? The flared connection, which has
a captive locknut on it, at the fire measures 7/16" in diameter.

Is it a stock item? Does it need Fernox or summat to seal it?

Si