Disconnecting, reconnecting and purging gas lines.
I need to disconnect the exterior gas line in order to reside my house. Once I'm ready to reconnect everything do I need to then purge air from the line at each individual appliance (range top, water heater and gas fireplace) or in just one location for the entire system?
Usually just a slit is made in the siding to get it over the piping & electrical conduit. Suggest contacting your utility regarding the disconnect from the main, if you do not want to cut the slit in the siding panel.
As for your question of purging, there is no need, just need to make sure that it does not leak when connected back up. From there you just have to relight the pilots on those appliances that use a standing pilot light.