In this video I am making a natural gas pipe connection. I go over the tools needed to create a leak free steel pipe fitting. The steel pipe threads are tapered in opposite directions. Therefore when tightening a pipe into a fitting, resistance happens and with the help of thread sealant, create a tight sealed fitting. You can use pipe dope sometimes called plumbers putty or Teflon tape. White Teflon tape is no good to use on gas pipe. Natural gas deteriorates the Teflon and pieces of it closes of the inlet of gas valves. Usually a yellow Teflon is used by most professionals. Yet many other colors are now on the market. Just make sure the Teflon is made to seal gas pipe. I prefer pope dope over Teflon for gas fittings.