Seems everybody that i'm working for are changing from propane..or even heat pumps to Natural Gas..I've plumbed in three this week..last week one of the one's i did had a leak..they all get inspected and pass before vectren will ever hang the meter..I climbed all over the new line under pressure..checking every joint..more than once..Finally found the leak ..right in the middle of a coupling...right in the middle,or actually right in the H in CHINA....pin hole leak....was really testing threadded ends for leaks..finally after the third time through....the bubble shows up..after removeing and replaceing ..you could see the bad sand cast from the inside.. I wonder what time will do to the US..with the inferrier parts that are being installed every day that come from China..