gas (propane) barbeque hookup

My Inlaws Have A New Gas Barbeque That Was Connected Recently.
They Have Propane Tanks With A Regulator And Also A Regulator On The Barbeque.
I Told Them They Don't Need That Extra Regulator Because It Cuts Down On The Flame.
Am I Correct?
Thanks
Ron

You are NOT correct. The regulator at the tank reduces the high pressure at the tank to service line pressure. Each device, like a stove, barbecue, furnace, etc has another regulator to reduce to the very low pressue required by the burner. The appliance...in this case your barbecue....is designed to burn at a certain BTU rate. Assuming the input is correct, pipes are not too small, etc.....that is what it will do. Increasing the pressure by eliminating either of the regulators would result in an improper flame, or no flame at all.