Steel water pipe in 6 in. and larger sizes general is covered by AWWA C200 standard. Additionally, AWWA Manual M11 states, "Current AWWA standards list coatings and linings for steel water pipe that are believed to be the most reliable, as proved in practice." Although many AWWA options are available and standardized for various coatings and linings for steel pipe, I don't believe galvanizing or galvanized steel pipe per se is currently represented by a "standard" in AWWA.
I suspect there are probably multiple ASTM standards covering other types and sizes of of steel pipes and tubes etc., including galvanized pipe.