Function of an Orifice in Gas Grills

Orifice Spud                     


You bought a gas grill for use with a propane bottle and now you moved to a home where there is natural gas. Think you can just hook it up? The answer is no. This is because the orifice size is different. Same holds true if you purchased a natural gas grill and moved to a home where you must purchase LP bottled gas. Here we will explain what the orifice is and its function in the gas grill.

The orifice, in gas grill applications, regulates the flow of gas either in a Natural Gas or LP Gas (Propane) application. The spud orifice is a male fitting (see far left picture) that will screw into the valve where as the hood orifice (see far right picture) is a female fitting that will screw onto the male valve end (see far right picture). You cannot operate a gas grill without an orifice.

The orifice hole size determines the BTU rating and the gas type of the grill. The BTU rating will determine the amount of heat produced by your grill burner. Gas types are not interchangeable. Natural Gas orifices will have a larger hole as it is a lower pressure gas and Propane is a compressed gas and the orifices will have a smaller hole. They are not interchangeable. You never want to use an orifice that is drilled for Natural Gas on Propane or Propane for Natural Gas. 

Using a Natural Gas orifice on a Propane grill will produce an abnormally large flame due to too much gas flowing through the hole and can be extremely dangerous.

Every grill has a BTU rating that is engineered and designed by the manufacturer. This BTU rating is located on the information sticker on every gas grill and will let you know the what the manufacturer has engineered each burner to produce. Therefore, Orifices are not "universal."  They not only will have different hole sizes but, they ill also have different diameter and thread size. Not all thread patterns are created equal.

If you need to change gas types, the grill must be converted. Changing orifice types or converting a gas grill should only be performed by licensed gas technician as it can be a potentially dangerous task. Both types of gas are flammable and should be repaired by professionals.

Conversion kits are sometimes available through the manufacturers since they will be drilled to the BTU specification of the brand and model grill you own. Many manufacturers are moving away from allowing the grills to be converted due to liability. It is difficult to control who is doing the conversion. Since it is gas and flammable the liability can be cost prohibitive especially if someone who is a novice is performing this task and they get hurt. 

Keep in mind that there are some valves that cannot be converted. One of these is the flame thrower valve. You can click on the link and read information on this valve.

In the aftermarket, there are some "blank" orifice options. They are called blank because there is a starter hole to allow for the specially designed gas drill bits to have a starting place. If an orifice needs replacement, there may be an aftermarket that will work. It must have the same threads in order to fit in the valve. 

Again, all drilling of these orifices needs to be performed by a licensed professional in your area.

If you have any questions, please email us at or call 877-983-0451

by Tracy Hollander on 3rd Aug 2017
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