What in the world is a Venturi?
The function of the venturi is to connect the control valves to the burners, to mix air and gas to help create the flame that your burner emits (like a carburetor for all you car nuts) and to reduce the pressure of the gas causing it to flow faster into the burner. The final function is where the tube gets it's name, the reduction in fluid pressure that results when a fluid flows through a constricted section of pipe is known as the Venturi Effect. Different grills will need different lengths and styles of venturis. Some venturis will include a mesh cover known as a spider guard. Spider guards are not necessary and do not impact the function of your venturis.