I recently called out the use of galvanized pipe used for some of the gas supply line. Here is what I put in the report.

A small section of galvanized pipe has been used for the gas supply line to the furnace. Galvanized pipe is steel pipe covered with a protective coating of zinc that greatly reduces its tendency to corrode and extends its life expectancy. It may be used in residential water supply lines, but not gas lines because natural gas causes the zinc to flake off and clog the system.

A local heating and cooling contractor evaluated the HVAC system and said that the galvanized pipe is ok. He also said that galvanized pipe that was known for the zinc to flake off is no longer made. What do you guys think.

Trent - The board archive is a great source of info. I did a quick search and found a thread about various materials, including galvanized, being used for gas. Our resident expert on such things, Bob Harper, replied that all the materials listed were approved for gas.
Gas Line - approved materials - Home Inspection & Home Inspector Services For Inspections and Inspectors

In Oregon it is allowed to use on gas lines, I checked with the county.