I want to run a gas line from the meter to a spa heater, a distance of about 10 feet. The existing line (being replaced) is flexible copper. I prefer to use something more like galvanized pipe. My concern is about corrosion between the (sometimes damp) sandy clay soil and the buried portion of the gas line. The gas pressure will only be about 5 psi, since it is drawn from the downstream side of the meter. Any ideas and/or suggestions about pipe material and depth of burial for such a line? City code does not give much direction about selection of pipe material, but I assume that some participants in this board who have done this before and have experienced advice to share. Thanks.