Propane line advice needed

[Laneman]

I live in a pier and beam home in the country. I currently have a propane tank in the back yard with buried galvanized pipe running from the tank, then under the house to a propane water heater in our hallway. I added a propane stove and a plumber teed in a length of CSST from the water heater stub to the kitchen stove. I would now like to move the water heater from the hallway to the garage. This means I need to run a new line under ground from the tank to the garage wall for the water heater. My plan is to then unhook one end of the CSST at the old water heater location, pass it through the kitchen wall, attach to exterior wall and tee into the new line at the garage wall location. I was going to use 3/4 soft copper with flare fittings from the tank, underground to the garage wall, then black pipe through the wall. At the outside I would add a threaded tee for the CSST to attach. The soil is clay alkaline, though I have seen many buried copper pipes hold up just fine after decades in this area. Just wanted to submit this plan for suggestions and tips. I read somewhere that one should use copper pipe that is rated for propane?

 

[Rancher]

propane tank in the back yard with buried galvanized pipe running from the tank

Galvanized pipe with propane is not to code (I think), it needs to be the plastic coated black steel pipe, or fully wrapped with pipe wrap, with a 2 layer overlap.

I could be wrong but that is what my building inspector would approve.

Rancher

 

[Sponsor]

 

[GrumpyPlumber]

Black mallable or copper are ok in my state for propane..natural gas however prohibits copper because of the corrosive sulfur content.
Other states won't allow black and you need galvanized, it all depends on your code.