Re: New Propane cilinders
First shut the bottle off.
Disconnect the propane line.
Reconnect propane line.
Turn propane bottle on.
Turn gas knob to on and light.
The problem comes if you open the know on the barbecue before the propane bottle is turned on. Then, when you shut it down do it in reverse order.
Barbecue to off and then the bottle.
Be patient, I knew a guy that made a valve bypass and his home blew up so really the valve is a good thing.