Hi .. i have recently purchased an old house and noticed that when i open the gas valve, a lot of rust comes out of the pipe .. non of the gas appliances have been installed yet (they are on order) .. I opened the valve for the stove more than 20 times throughout the day (about 10 sec each time) .. and the rust doesn’t seem to get any less .. Does this have anything to do with the fact that the has been vacant for more than 2 years and no one has used it? is it normal? should i keep running it until the dust stops or is it time for new pipes? .. i have never heard anyone changing gas pipes inside the house .. any suggestions?