yes they can a lot of people will use neon paint to make them visable
It depend on how cold it gets in the basement.
OSHA has not established color code requirements for natural gas lines.
Natural gas sould be transfered in yellow pipes.
What is the application as many times such as natural gas it is permissible as gas lines exposed to the elements have to be protected painted / insulated or galvanized piping vanized piping
You DONT
Pressure.
natural gas?
pipe lines and stoves
you dont.and its basement.
Usually not.
Try Nitrogen (For natural gas lines NOT cars /trucks etc)
yes. Generally caused by ruptured natural gas lines.