What Size Of Orfice For Natural Gas Grill

Catechumen a gas barbecue grill from natural gas to propane or propane to natural gas with orifice plugs. Mostly if we have to convert an orifice fabricated for LP employ into an orifice that will burn NG all we need to exercise is make up one's mind the correct size and drill the orifice. This is considering LP as a vaporized gas has a much smaller mass than NG and this means the LP orifice will have a much smaller hole than the aforementioned BTU's for NG which needs a much larger pigsty in the orifice. Using the regulated pressure, BTU's per burner and an orifice drill flake nosotros simply check the chart to determine the right size and drill the orifice to brand the smaller LP opening into a bigger NG opening.

If we are converting a BBQ grill from natural gas to propane we volition commonly take to remove the NG orifices and replace them with LP orifices considering the larger pigsty cannot exist fabricated smaller. Unfortunately a new orifice drilled for LP gas is not always available for every barbecue grill on the planet. Necessity is the female parent of invention — if we are converting a charcoal-broil and cannot locate new orifices we take to figure out how to make that larger NG pigsty into a smaller LP hole.

spud orifice drilled for use in a NG gas grill

A Spud orifice has male threads and this one is drilled for NG

This Spud mode orifice is from a NG charcoal-broil grill and information technology is not a brass fitting of a size that we take new orifices that tin can exist drilled to whatever size nosotros want them to exist. In order to convert this charcoal-broil to use liquid vaporized propane nosotros demand to make the hole in the orifice smaller.

If we are able to purchase a replacement orifice that can be drilled to the size we demand that should always be the correct move. Often finding a replacement orifice is not possible and because the valve and orifice tin can be fragile we need the size and threading to be exact. Using the original orifice is about as exact as we tin can get. When a replacement is not available we will ruin and then repair the original orifices to brand the larger natural gas hole into a smaller propane hole for our depression pressure appliances: barbecues, grills, fireplaces, fire pits, side burner ranges and smokers.

spud orifice to be drilled.

Irish potato orifice to be drilled for plug.

In social club to seal the hole the beginning footstep is to get a brass orifice plug and lucifer the cylinder tube of the plug with a drill bit. I use a "21" orifice bit which is Huge and only needs to be reamed back and along a trivial chip.

Drill the Huge pigsty in the orifice. At this point the orifice is totally ruined if we practise non plug information technology correctly because Nothing needs this big of an orifice opening. Drill the orifice taking care of the size based on the plug and beingness careful not to damage the threaded inner walls of the back of the orifice when working with modest irish potato style orifices similar this one in the picture.

drilled spud orifice matched to plug

irish potato drilled to match brass plug

Once we have drilled the large hole in the orifice we need to check it with the plug. Sometimes we'll need a bigger drill bit or only need to ream the drill bit dorsum and forth a little to open the hole. The plug should get-go into the pigsty only not go in easily.

Utilise a hammer to lightly farce the plug into the hole. Be conscientious not to hit the soft brass so hard we ruin the original orifice. I usually start with slight taps and piece of work upwardly watching the plug. Use a strong solid base; zilch ruins the strike more a moving table or soft flooring that volition move when hit.

match drilled orifice hole to plug and punch

Match the cylinder of the plug to the hole in the orifice.

We too have to lucifer the back end of the orifice with the large part of the dial. The minor tip will be modest enough for the back-end of the plug but as it increases in bore note that larger diameter will be hit into the back of the orifice and will tear the brass threads if it is also bog to fit into the back opening. This punch shown in the image is a function of the kit and there are bigger punches only not smaller ones. When I need a smaller punch I utilize a small phillips-head screwdriver equally a punch and spreader so I do non tear the orifice.

Recall the whole reason we're going through this process is because replacement orifices are not available and nosotros have to use our original orifices. Check twice and so you lot do non rip the orifice and have to supervene upon an unabridged valve unproblematic to change the orifice.

plug the hole in the orifice

plug the pigsty in the orifice by hand and so with a hammer.

One time we accept chosen a good dial we demand to get the plug into the large pigsty we drilled into this spud orifice.

Use a hammer to forcefulness it through. If y'all over-drilled, deal with it past testing at the terminate and using a plumbers putty when you lot supervene upon the leaking plug. Optimally we desire the plug too tight to be able to exist placed past hand. Nosotros want it to be forced with a hammer so information technology is as tight equally possible.

plug the orifice hole with brass plug

plugged orifice seems tight but is not completely filled, yet.

Makes sure to sink the plug into the orifice completely so the head is tight confronting the caput of the orifice. We want the enlarged part of the plug to completely hide the hole we drilled so no gas can escape sideways after.

punch backend to spread the plug in the orifice

One time the plug is tightly inserted from the forepart of the orifice it feels tight but years of use can modify that. The next step is to solidify the plug by using the spreader punch. Insert the punch you chose from the back of the orifice inserting it into the hole of the plug. Smack it with the hammer, hard enough to spread and maybe tear the brass. Place the orifice upside-downwardly so the rounded plug caput is on a solid flooring. This manner when we smack the back side of the plug hard we are non risking dislodging the plug from the orifice. The tubular back-end of the plug that is within the orifice will be forced to spread and pull the caput tighter against the outer front of the orifice.

Orifice plug punch spreads backend to seal the hole

Orifice plug dial spreads backend to seal the hole

I can only barely tell with the small orifice because it is and then tight inside the back stop of this spud. The left paradigm is the plug only pressed into the orifice. The right paradigm is the plug spread to tighten the plug into the orifice tight enough to keep it there forever (or until we take to change information technology again and remove it past drilling through the plug).

redrill NG or LP opening in grill orifice

Drill Newly Sealed Orifice For Correct BTU'due south and Fuel Type.

Once the plug is forced tight into the orifice the result is a orifice with the threading we require to attach to our barbecue grill control valve merely without a much-besides-large hole drilled in an orifice designed for apply burning natural gas. Now our orifice is sealed and we can drill the orifice with what ever size orifice drill fleck we demand.

Determining the orifice hole size means knowing the gas type, amount of regulated gas force per unit area and BTU's for each burner. For instance LP standard regulators will regulate vaporized liquid propane at 11″. Like whatsoever plumbing gas pressure is generally measured in pounds per square inch. Gas fireplaces, barbecues, grills and smokers use a very low-pressure setting well below one pound per square inch so we measure the pressure in terms of water-column deportation. In a manometer the gas pressure is attached to a tube of water and the pressure is simply potent enough to push the water so far in the tube. Natural gas has more than mass just is ordinarily regulated between 2 inches and 9 inches whereas LP is e'er regulated at 10-11 inches for low-pressure level appliances.

Orifice sizing charts will be in columns of Inches starting with 2 and moving upwardly to xi inches for LP gas. The rows of the chart will show BTU'south. Nosotros observe the BTU for the burner and match the proper BTU in the column of regulated gas pressure we're

valve orifice burner assembly