Most barbecues are controlled by the control knob that is attached the the control valve. The control valve has an orifice at the tip and the orifice slides into the burner to spit the gas into the burner. However, some control valves are not installed close enough to the barbeque burners to attach in this way.
This barbecue grill from bbq galore stores is such an example. The tip of the control valve does not have an orifice that slides into the barbeque burner. Instead there is an aluminum gas line that extends from the tip of the valve and the orifice is attached to the other end of the gas line.
The control valves we sell at Grill-Repair.com for barbecues like this are manufactured to have an orifice attached at the end of the valve to control the amount of liquid propane or natural gas going into the burner. If this control valve was going to be used in a turbo, kalamazoo, cook on or any other barbecue grill that has an extension gas line connecting the control valve to the burner we can add a compression fitting to convert the tip of the valve into a gas line extension. The instructions for using a compression fitting to add an extented gas line connecting the control valve to the burner follows.
The same control valve as the one on the black and white drawing is in the picture above. This control valve can be used on Cook-On barbecues, Turbo models like the Grand Turbo and the Turbo Select and many others. The compression fitting and the aluminum gas line is also shown in this image.
One half of this compression fitting is female pipe thread to attach to the barbecue grill control valve. The other half unscrews to expose the flared piece. This flare slides onto the tip of the aluminum gas line. When the top is screwed back onto the other side of the fitting the brass flare is soft enough to flare out and seal the connection. Once sealed this flare cannot be re-used but the gas line is now sealed to the control valve. The gas line can be unscrewed at the valve for maintenance later if it becomes necessary to replace the valve. Do not push the aluminum (or copper) tube too far into the control valve.
Compression fittings are available in a wide array of sizes on both sizes. The size of the gas line does affect the amount of gas travelling through but with a low pressure appliance like a gas log fireplace or an outdoor barbecue grill an eighth of an inch to a quarter inch is acceptable unless there is a lot of gas line added for some uncommon reason.
The compression fitting for the other end of the aluminum gas line has a 1/8 male pipe thread side just like the control valve. This threaded side screws into the hood style orifice just like the control valve would have. This aluminum gas line is a 3/16 line so the other side of the fitting is a 3/16 compression fit.
Again the compression side of the brass gas fitting comes apart to reveal the soft brass flare. The soft brass flare fits onto the aluminum gas line. The flare should fit snug. Like with the female side compression conversion fitting slide the flare about a quarter inch onto the aluminum (or copper) gas line and then tighten the nut back to the fitting. The soft brass flare will spread with the tension and seal the gas line to the fitting.
The hood style orifice is now attached and sealed safely to the aluminum gas hose that is also attached to the control valve. If the orifice has to be converted at some future time the fitting is still able to be unscrewed from inside the orifice but if the fitting is separated at the center where the flare piece is compressed it is no longer useful. The orifice on any gas barbecue grill has a hole in the tip that is sized to allow a specified amount of gas through to the barbecue grill burners. Liquid propane vaporizes and feeds through the valve in a compressed form so the hole in the orifice is very small. Natural gas is a true gas in its natural state and has more mass so the orifice opening is much larger. When a gas barbeque grill needs to be converted from one gas type to another the orifices can be removed and changed to the proper size for propane or natural gas. When converting from propane to natural gas the orifice can be removed and drilled to the larger size since the natural gas orifice has a larger opening than the hole in the propane orifice. Because liquid propane is always pulled from a reservoir propane is always regulated at the same pressure for low pressure appliances like gas barbecues and gas log fireplaces. Natural gas can be regulated anywhere from 2 or 10 inches of water column displacement but the environmental temperature and the altitude can affect this. Recently we have had a lot of customers repairing gas grills with extensions attached to their control valves. This is actually very rare today but a lot of older barbecues utilized this technique of attaching the control valve to the gas BBQ burners. For additional information about control valves, orifices, gas lines, regulation or any other barbecue grill repairs contact Grill-Repair.comat 954-2-Grill-2.