The burner rusted out in my gas grill so I purchased a replacement - a universal burner that was approximately the same size. It was easy to assemble and install. However, the ends of the gas tubes that connect to the gas line ends by the control knob have a wire-mesh webbed opening. When I attach these, the ends coming from the control knobs do not go beyond the webbed opening. The old line had a similar mesh opening that was even longer.
How is this not a gas leak in the line?
Those openings are the air inlet. The gas line ends in a small diameter opening that inserts into the burner assembly. The small gas opening causes the gas to flow out at a high velocity, which causes the pressure to be a bit lower at that point because of the Bernoulli effect. So instead of gas leaking out, air actually flows in to mix with the gas before it gets to the burner exit where the mixture burns. There should be an adjustable metal sleeve which partially covers the opening. By moving the sleeve to let more or less air in, you can adjust the flame until you have the right ratio of air to gas.
