Plumbing and Valves (and Orifices)
Introduction
To brew, one needs a source of heat to mash, lauter, sparge, and boil. Unless you are a large commercial brewery using steam, it’s safe to assume you are either going to use electric or gas. This section discusses the considerations, design, and build out of a low pressure LP (liquefied petroleum, aka propane) gas system that is adapted for the stand that we have earlier discussed. There are other options – high pressure LP or low pressure natural gas (if you have gas service at your place of brewing, and you can permanently alter the gas plumbing). I built my rig using low pressure LP and I fully intend to convert to natural gas down the road, it’s extremely easy and cheap to swap between the two.
There are discussions on various forums about LP vs natural gas. Both have their distinct advantages and disadvantages. LP’s biggest advantage is that its portable and cheap to get set up on (if you ever want to take your show on the road to a buddy’s place or if your local HBS or HBC does group brews). Or if you want to move your brewstand from your driveway to your backyard. Its biggest drawback is that it comes in a tank that needs to be refilled from time to time, and can run out mid-brew. It is also costlier than natural gas. The biggest advantage to natural gas is it never runs out (provided your up on your utility bill), and it’s cheaper than LP. The only (and frankly biggest) drawback to using natural gas is that it requires installing a quick disconnect onto your natural gas plumbing. This either means hiring a professional (which is the only avenue I can suggest if you go this route), or doing it yourself if you know how to plumb gas piping. Other than this potentially high initial cost, the other main drawback is that quick disconnect is fixed in one spot, so your mobility is limited.
For me, the LP route was what fit best. For you, it might be natural gas. The only difference between the two is going to be your orifice size on your burner and your control valve set up (low pressure LP is 11” WC and natural gas is generally 3.5-5” WC).
Let’s explain the difference between high pressure LP and low pressure LP. Many burners out there that are used by homebrewers are high pressure LP. They blow a lot of gas thru a tiny orifice at high pressure, which kicks out a LOT of BTUs. Low pressure LP requires a larger orifice, but operates at much lower pressure and uses a lot less gas. However, the trade off here is that you need a much bigger burner to get the same amount of BTUs as the smaller high pressure LP burner.
So what is an orifice (other than a word that makes us giggle a little inside when we hear it)? When used in gas flow, it refers to the hole that “meters” the gas from the supply line into the item that is using it. All gas appliances have orifices. The size is based on the number of BTUs that the item using the gas requires. There are many charts on various sites that show drill size, orifice size, and BTU for both natural gas and LP. You will find your orifice in the end of the fitting that threads into your burner. As of writing this, I haven’t found a burner that comes with a low pressure LP orifice. They may be advertised as “low pressure”, but you may not get what you expect.
At first, I messed around with the orifices that came with the burners and landed on a 5/64" orifice size. Then I came across these from brewers hardware. They are exactly what you need for this, and they fit perfectly in the BG14. Just make sure you use Teflon tape when you install them. Well worth the $7 bucks a pop.
Upstream (toward the tank) from the orifice is the hose, then the regulator. Most of us are familiar with propane grills and how they are hooked up to the propane tank using an ACME nut. The regulator for gas grills typically drops the pressure to 11” WC. The regulator used in this setup needs to be an 11” WC regulator. You can get fancy with a dual stage regulator, but a single stage will work fine and cost significantly less. The dual stage’s main advantage is that it will give smoother flow. When I say 11” WC, that means 11 inches of water column. This is NOT 11 pounds per square inch (PSI). This is enough pressure to hold an 11 inch water column in a manometer. Feel free to research this online if you are interested in where the unit of measurement comes from, I am not going to get into here for simplicities sake. For reference, 11” WC is a little under ½ PSI.
Why 11” WC? Simple. The control valves used on this setup are the same ones you would find on your furnace or hot water heater. You can buy high pressure industrial valves, but instead of ~$65 per valve, you will be spending ~$300 per valve. Most homebrewers use the Honeywell 8200 appliance valves. These valves have a built in regulator that will blow out if more than 11” WC LP is pushed thru them. Therefore, to have automation, we need to use the 11” WC low pressure LP!
The last thing about the hose/regulator connection to the tank. The QCC connection and ACME nut color. I spent HOURS trying to figure this out, destroyed an orifice, and only was able to find the info buried on some forum unrelated to homebrewing. So when I hooked everything up and tried out my burner, I got a really small flame. Opened the orifice up, same small flame. Opened the orifice all the way to 3/16” and still small flame. When opening the tank slowly, the gas flow was good but then a small click noise at the regulator and the gas flow dropped dramatically.
As it turns out, there is a safety excess flow valve in the ACME nut/QCC connector to the propane tank, and there are different kinds. If you have a black ACME nut, it is rated somewhere between 50-100k BTU/hr, green is 250k BTU/hr, red is 400k BTU/hr. I had a black ACME nut. Swapped it out with a green, put in a new orifice, and it worked stellar. A lot of folks recommend using a POL connector, but this eliminates the excess flow valve. It’s there for a reason – if your hose bursts while you’re over hooking up your garden hose, getting hops out of the fridge, or walked away during mash, it’ll just blow propane, potentially causing an explosion. Also – the ACME nut can be connected or disconnected by hand. The POL connector needs a wrench to connect and disconnect.
When you get your burner, check to see how it works. The flame should be big and blue, maybe with small orange tips but there should be almost no orange flame. If you didn’t pay attention in high school chemistry when the teacher was showing how to operate the Bunsen burners, orange flame is from the fuel/air mixture being too rich. This burns a lot of fuel, and isn’t a really hot flame. Blue flame is when the mixture is leaned out, causing more air, and therefore oxygen, to be combusted. The more oxygen, the hotter the flame. Too much oxygen and too little fuel, the flame will go out or die way down.
To test your burner, we are going to hook the regulator and hose assembly to your tank, and then the 3/8” flare fitting should go right on the orifice fitting on the burner. DO NOT HOLD THE BURNER – IT WILL GET VERY HOT VERY FAST. Using a long gill burner lighter or match, get a flame going (either by lighting the match or lighting the lighter). Hold this at the burner head and then slowly turn on the gas at the tank. You should be able to hear the gas flowing, and the burner should ignite rather rapidly. If you either do not hear gas or see fire, shut off the tank. Disconnect your hose from the tank and reconnect it. Try again, opening the tank valve slowly. You should have success. If not, make sure you have the right color (green) ACME nut.
You can adjust the flame with the air shutter on the burner. Rotate it to open or close the holes. The burner body is basically a venturi – its necked down and the flowing gas causes the velocity to increase, decreasing the internal pressure of the gas/air mixture in the throat of the venturi, drawing more air in thru the air shutter. If you close the shutter, you restrict the flow, making the mixture richer (higher fuel to air ratio). If you open it, you lean the mixture (lower fuel to air ratio). If you have it adjusted full open and you have large orange flames, your orifice size is too big. Follow the next section to avoid scrapping an orifice and having to buy a new one.
How to adjust orifice
Start out with the factory orifice size. Hook up the burner and light it. Rotate the air shutter until you find the spot that you are getting good blue flame with small orange tips. Check the size of the flame – it should be ample, 2-3 inches high, and throwing off good heat. If it’s not high enough, or you want it bigger, shut it down, and remove the orifice fitting. You will need a micro drill bit set to adjust it, size 41-60 bits. Open the hole up to the next size. The orifices I got came factory as size 57s. It takes a while, but don’t jump more than a size or two each iteration. Put it back together and try it out. Adjust the air shutter again, and check your flame. Repeat until you are happy with your flame size.
Gas valve selection
There are different kinds of gas valves out there that you can use. They have different BTU ratings, inlet/outlet sizes, operate on different voltages, etc. You can find 110 VAC valves, but they are usually pretty expensive. You can find cheap ones that are crap and have no safety features. This is fine if you want to sit adjacent to your propane tank with one hand on the valve incase the coil on the valve solenoid shorts and sparks and lights up the highly flammable propane flowing thru it. They also don’t have a pilot thermocouple that will prevent the valve from opening if the pilot blows out. Hey, you’re going for automation and you don’t want to have to worry about this stuff while you’re trying to brew.
I landed on Honeywell VR8200A2132 valves. They also have a variant that is an A2124 which comes with the thermocouple (but I don’t think it comes with a pilot assembly which you will need). I will be discussing the A2132 version. This valve operates on 24 VAC, and has pilot and thermocouple hookup. When you light the pilot, it heats the thermocouple, allowing the valve to open when commanded to do so. If the pilot blows out for some reason, the thermocouple cools, preventing the valve from opening and blowing propane freely which can cause an explosion. This valve also has 1/2” inlet and outlet connections. The VR8300 series comes with 3/4” connections, and a bushing to reduce from 3/4” to 1/2". You can use either, I used the VR8200 so it would be one less threaded connection. 3/4" valves have a higher BTU/hr rating (bigger pipe means more gas), but that size is overkill in this application.
To be honest, I did a lot of looking at stuff on ebay as the gas valves there are much cheaper. However, few are rated for LP or NG. The seal material will degrade over time and leak fuel gas if you get a valve that is not made for LP or NG. Considering safety and peace of mind, the extra $100 bucks on the set of valves is worth it here.
Gas valve conversion
Ok, so you have your gas valves. 99.9% of the time they come set up for natural gas. You need to convert it to LP. No need to worry or become intimidated by it – it takes about 3 minutes and uses a mid sized flat head screwdriver. Your valve should have come with a natural gas to LP conversion kit. Typically, the kit has a spring, o-ring, screw, and sticker to put on the valve saying its converted to LP. Based on the valve you have, you need to follow the instructions that came with the conversion kit. Hang on to the removed parts in case you ever want to convert your setup to NG.
Getting pipe
Residential NG is plumbed with black iron pipe. This is commonly available at Home Depot and Lowes, and it’s cheap. Some will argue that you can also use galvanized, and it’s immediately adjacent to the black iron, but most residential building codes call for black iron. Not that you are building to code here, but it’s good practice to stick with what is deemed safe for housing applications. People will say that galvanized is fine, and for all practical purposes it probably is. In fact, in outdoor applications galvanized is recommended, or its advised to paint black iron to prevent corrosion. Other people will say that it (the galvanized coating) can flake off inside the pipe and cause issues with debris getting in the orifices. End of the day, it’s your choice, I went with black iron. You can use either, but corrosion will not be a consideration unless you are keeping your stand in the elements.
You want your valves to be generally close to where the ends of your burners will be. Mine are mounted at an angle and not straight out the back of the stand. Get the pipe cut and threaded to the lengths that you need. Mine were 17” and 32”. Remember that at the propane inlet you need it to stick out an inch or two past your stand so you can connect to it. I also used 5” nipples to stand up from the tee’s to mount the valves on. You also will need one 1/2" tee and 1/2" elbow (not a street elbow, both ends need to be female).
From the valve to the burner you need the flexible appliance hoses. These are the yellow hoses that are also sold at Home Depot or Lowes. Mine are 24” long and 1/2" OD. They come with the fittings you need to attach it to the gas valve, which is a FIP connection. The burner orifice end that the gas line goes to is a 3/8” flared connection, and the flex hose has 1/2" female flared. Basically, the flex hose is 1/2” flare and comes with fittings that adapt it to MIP (male pipe thread). You will need an adapter that is 3/8" female flare X 1/2" male flare. The orifice assembly and flex line flare are both SAE 45 degree flare. I found these adapter fittings on eBay.
Your piping and valves will be MIP. The hose from your propane tank will be flared, so you need to buy a fitting that goes from 1/2” FIP (that goes on the end of the iron pipe) to 3/8” male flare (that the propane tank hose connects to). If not in the hardware store, they are available online from various places.
Build out
When assembling your piping, you need to use Teflon tape or you will gall the threads. Basically, they will not seal up right and they will more or less freeze up and lock together. You can’t use white plumbing Teflon tape – this isn’t rated for fuel gas use. There is yellow Teflon tape made just for this purpose. You need a roll of it.
To attach the plumbing to the stand, I used 1/2" pipe hanging brackets. This requires drilling and tapping holes in the stand (which we will need to also do to mount the pumps, burners, and burner grills), so pick up a tap and die set. You will need the SAE version, and it should come with sizes from #6 up thru 1/4". You will also need cutting fluid to tap the holes. This is also sold at the hardware store.
The easiest way to put this all together is to screw together all the plumbing first. Wrap the Teflon tape around the male threads of the pipe, then screw it into the female fitting. Using a pipe wrench, tighten the piping together. Both the 5” nipples need to run parallel to each other. Lastly, attach your two valves to the plumbing. The knobs should face the same direction, and will face out the back of your stand.
Put the built up plumbing and valves on the back of your stand, and let the valves sit on the bottom cross beam. Line up the pipe hanging bracket and mark the holes out. I mounted mine using #8-32 x 3/4” screws. Get your tap and die set, and using the provided chart, get the appropriate drill bit (for #8-32 thread it should be the #29 bit). Center punch the hole locations, then drill the holes. Using the tap and cutting oil, thread the holes. I used three brackets and it’s pretty sturdy. Two brackets are common to the 5” nipples and bottom cross beam, and one is common to the 17” pipe and the leg of the stand.
Teflon tape the last male pipe end where you will hook up the gas, and tighten on your 1/2" FIP to 3/8” flare fitting. Teflon tape the fittings for the flex lines and put them on the gas valves. Note that if you build drip/heat shields for the gas valves, the best place to attach them is here, between the fitting and the valve. Once attached you might want to run a bead of silicone around them to keep the top water tight.
The last thing I added for the gas system was a hook to hang the coiled hose on. Here #10-24 x3/4” screws were used to attach it to the stand. The hook I used had a small tab that needed to be ground off prior to installing. After grinding it off I painted it to prevent corrosion, and installed it.
That just about concludes the gas system hook up, from the propane tank to the flex lines going to the burners, with the exception of the pilots.
To brew, one needs a source of heat to mash, lauter, sparge, and boil. Unless you are a large commercial brewery using steam, it’s safe to assume you are either going to use electric or gas. This section discusses the considerations, design, and build out of a low pressure LP (liquefied petroleum, aka propane) gas system that is adapted for the stand that we have earlier discussed. There are other options – high pressure LP or low pressure natural gas (if you have gas service at your place of brewing, and you can permanently alter the gas plumbing). I built my rig using low pressure LP and I fully intend to convert to natural gas down the road, it’s extremely easy and cheap to swap between the two.
There are discussions on various forums about LP vs natural gas. Both have their distinct advantages and disadvantages. LP’s biggest advantage is that its portable and cheap to get set up on (if you ever want to take your show on the road to a buddy’s place or if your local HBS or HBC does group brews). Or if you want to move your brewstand from your driveway to your backyard. Its biggest drawback is that it comes in a tank that needs to be refilled from time to time, and can run out mid-brew. It is also costlier than natural gas. The biggest advantage to natural gas is it never runs out (provided your up on your utility bill), and it’s cheaper than LP. The only (and frankly biggest) drawback to using natural gas is that it requires installing a quick disconnect onto your natural gas plumbing. This either means hiring a professional (which is the only avenue I can suggest if you go this route), or doing it yourself if you know how to plumb gas piping. Other than this potentially high initial cost, the other main drawback is that quick disconnect is fixed in one spot, so your mobility is limited.
For me, the LP route was what fit best. For you, it might be natural gas. The only difference between the two is going to be your orifice size on your burner and your control valve set up (low pressure LP is 11” WC and natural gas is generally 3.5-5” WC).
Let’s explain the difference between high pressure LP and low pressure LP. Many burners out there that are used by homebrewers are high pressure LP. They blow a lot of gas thru a tiny orifice at high pressure, which kicks out a LOT of BTUs. Low pressure LP requires a larger orifice, but operates at much lower pressure and uses a lot less gas. However, the trade off here is that you need a much bigger burner to get the same amount of BTUs as the smaller high pressure LP burner.
So what is an orifice (other than a word that makes us giggle a little inside when we hear it)? When used in gas flow, it refers to the hole that “meters” the gas from the supply line into the item that is using it. All gas appliances have orifices. The size is based on the number of BTUs that the item using the gas requires. There are many charts on various sites that show drill size, orifice size, and BTU for both natural gas and LP. You will find your orifice in the end of the fitting that threads into your burner. As of writing this, I haven’t found a burner that comes with a low pressure LP orifice. They may be advertised as “low pressure”, but you may not get what you expect.
At first, I messed around with the orifices that came with the burners and landed on a 5/64" orifice size. Then I came across these from brewers hardware. They are exactly what you need for this, and they fit perfectly in the BG14. Just make sure you use Teflon tape when you install them. Well worth the $7 bucks a pop.
Upstream (toward the tank) from the orifice is the hose, then the regulator. Most of us are familiar with propane grills and how they are hooked up to the propane tank using an ACME nut. The regulator for gas grills typically drops the pressure to 11” WC. The regulator used in this setup needs to be an 11” WC regulator. You can get fancy with a dual stage regulator, but a single stage will work fine and cost significantly less. The dual stage’s main advantage is that it will give smoother flow. When I say 11” WC, that means 11 inches of water column. This is NOT 11 pounds per square inch (PSI). This is enough pressure to hold an 11 inch water column in a manometer. Feel free to research this online if you are interested in where the unit of measurement comes from, I am not going to get into here for simplicities sake. For reference, 11” WC is a little under ½ PSI.
Why 11” WC? Simple. The control valves used on this setup are the same ones you would find on your furnace or hot water heater. You can buy high pressure industrial valves, but instead of ~$65 per valve, you will be spending ~$300 per valve. Most homebrewers use the Honeywell 8200 appliance valves. These valves have a built in regulator that will blow out if more than 11” WC LP is pushed thru them. Therefore, to have automation, we need to use the 11” WC low pressure LP!
The last thing about the hose/regulator connection to the tank. The QCC connection and ACME nut color. I spent HOURS trying to figure this out, destroyed an orifice, and only was able to find the info buried on some forum unrelated to homebrewing. So when I hooked everything up and tried out my burner, I got a really small flame. Opened the orifice up, same small flame. Opened the orifice all the way to 3/16” and still small flame. When opening the tank slowly, the gas flow was good but then a small click noise at the regulator and the gas flow dropped dramatically.
As it turns out, there is a safety excess flow valve in the ACME nut/QCC connector to the propane tank, and there are different kinds. If you have a black ACME nut, it is rated somewhere between 50-100k BTU/hr, green is 250k BTU/hr, red is 400k BTU/hr. I had a black ACME nut. Swapped it out with a green, put in a new orifice, and it worked stellar. A lot of folks recommend using a POL connector, but this eliminates the excess flow valve. It’s there for a reason – if your hose bursts while you’re over hooking up your garden hose, getting hops out of the fridge, or walked away during mash, it’ll just blow propane, potentially causing an explosion. Also – the ACME nut can be connected or disconnected by hand. The POL connector needs a wrench to connect and disconnect.
When you get your burner, check to see how it works. The flame should be big and blue, maybe with small orange tips but there should be almost no orange flame. If you didn’t pay attention in high school chemistry when the teacher was showing how to operate the Bunsen burners, orange flame is from the fuel/air mixture being too rich. This burns a lot of fuel, and isn’t a really hot flame. Blue flame is when the mixture is leaned out, causing more air, and therefore oxygen, to be combusted. The more oxygen, the hotter the flame. Too much oxygen and too little fuel, the flame will go out or die way down.
To test your burner, we are going to hook the regulator and hose assembly to your tank, and then the 3/8” flare fitting should go right on the orifice fitting on the burner. DO NOT HOLD THE BURNER – IT WILL GET VERY HOT VERY FAST. Using a long gill burner lighter or match, get a flame going (either by lighting the match or lighting the lighter). Hold this at the burner head and then slowly turn on the gas at the tank. You should be able to hear the gas flowing, and the burner should ignite rather rapidly. If you either do not hear gas or see fire, shut off the tank. Disconnect your hose from the tank and reconnect it. Try again, opening the tank valve slowly. You should have success. If not, make sure you have the right color (green) ACME nut.
You can adjust the flame with the air shutter on the burner. Rotate it to open or close the holes. The burner body is basically a venturi – its necked down and the flowing gas causes the velocity to increase, decreasing the internal pressure of the gas/air mixture in the throat of the venturi, drawing more air in thru the air shutter. If you close the shutter, you restrict the flow, making the mixture richer (higher fuel to air ratio). If you open it, you lean the mixture (lower fuel to air ratio). If you have it adjusted full open and you have large orange flames, your orifice size is too big. Follow the next section to avoid scrapping an orifice and having to buy a new one.
How to adjust orifice
Start out with the factory orifice size. Hook up the burner and light it. Rotate the air shutter until you find the spot that you are getting good blue flame with small orange tips. Check the size of the flame – it should be ample, 2-3 inches high, and throwing off good heat. If it’s not high enough, or you want it bigger, shut it down, and remove the orifice fitting. You will need a micro drill bit set to adjust it, size 41-60 bits. Open the hole up to the next size. The orifices I got came factory as size 57s. It takes a while, but don’t jump more than a size or two each iteration. Put it back together and try it out. Adjust the air shutter again, and check your flame. Repeat until you are happy with your flame size.
Gas valve selection
There are different kinds of gas valves out there that you can use. They have different BTU ratings, inlet/outlet sizes, operate on different voltages, etc. You can find 110 VAC valves, but they are usually pretty expensive. You can find cheap ones that are crap and have no safety features. This is fine if you want to sit adjacent to your propane tank with one hand on the valve incase the coil on the valve solenoid shorts and sparks and lights up the highly flammable propane flowing thru it. They also don’t have a pilot thermocouple that will prevent the valve from opening if the pilot blows out. Hey, you’re going for automation and you don’t want to have to worry about this stuff while you’re trying to brew.
I landed on Honeywell VR8200A2132 valves. They also have a variant that is an A2124 which comes with the thermocouple (but I don’t think it comes with a pilot assembly which you will need). I will be discussing the A2132 version. This valve operates on 24 VAC, and has pilot and thermocouple hookup. When you light the pilot, it heats the thermocouple, allowing the valve to open when commanded to do so. If the pilot blows out for some reason, the thermocouple cools, preventing the valve from opening and blowing propane freely which can cause an explosion. This valve also has 1/2” inlet and outlet connections. The VR8300 series comes with 3/4” connections, and a bushing to reduce from 3/4” to 1/2". You can use either, I used the VR8200 so it would be one less threaded connection. 3/4" valves have a higher BTU/hr rating (bigger pipe means more gas), but that size is overkill in this application.
To be honest, I did a lot of looking at stuff on ebay as the gas valves there are much cheaper. However, few are rated for LP or NG. The seal material will degrade over time and leak fuel gas if you get a valve that is not made for LP or NG. Considering safety and peace of mind, the extra $100 bucks on the set of valves is worth it here.
Gas valve conversion
Ok, so you have your gas valves. 99.9% of the time they come set up for natural gas. You need to convert it to LP. No need to worry or become intimidated by it – it takes about 3 minutes and uses a mid sized flat head screwdriver. Your valve should have come with a natural gas to LP conversion kit. Typically, the kit has a spring, o-ring, screw, and sticker to put on the valve saying its converted to LP. Based on the valve you have, you need to follow the instructions that came with the conversion kit. Hang on to the removed parts in case you ever want to convert your setup to NG.
Getting pipe
Residential NG is plumbed with black iron pipe. This is commonly available at Home Depot and Lowes, and it’s cheap. Some will argue that you can also use galvanized, and it’s immediately adjacent to the black iron, but most residential building codes call for black iron. Not that you are building to code here, but it’s good practice to stick with what is deemed safe for housing applications. People will say that galvanized is fine, and for all practical purposes it probably is. In fact, in outdoor applications galvanized is recommended, or its advised to paint black iron to prevent corrosion. Other people will say that it (the galvanized coating) can flake off inside the pipe and cause issues with debris getting in the orifices. End of the day, it’s your choice, I went with black iron. You can use either, but corrosion will not be a consideration unless you are keeping your stand in the elements.
You want your valves to be generally close to where the ends of your burners will be. Mine are mounted at an angle and not straight out the back of the stand. Get the pipe cut and threaded to the lengths that you need. Mine were 17” and 32”. Remember that at the propane inlet you need it to stick out an inch or two past your stand so you can connect to it. I also used 5” nipples to stand up from the tee’s to mount the valves on. You also will need one 1/2" tee and 1/2" elbow (not a street elbow, both ends need to be female).
From the valve to the burner you need the flexible appliance hoses. These are the yellow hoses that are also sold at Home Depot or Lowes. Mine are 24” long and 1/2" OD. They come with the fittings you need to attach it to the gas valve, which is a FIP connection. The burner orifice end that the gas line goes to is a 3/8” flared connection, and the flex hose has 1/2" female flared. Basically, the flex hose is 1/2” flare and comes with fittings that adapt it to MIP (male pipe thread). You will need an adapter that is 3/8" female flare X 1/2" male flare. The orifice assembly and flex line flare are both SAE 45 degree flare. I found these adapter fittings on eBay.
Your piping and valves will be MIP. The hose from your propane tank will be flared, so you need to buy a fitting that goes from 1/2” FIP (that goes on the end of the iron pipe) to 3/8” male flare (that the propane tank hose connects to). If not in the hardware store, they are available online from various places.
Build out
When assembling your piping, you need to use Teflon tape or you will gall the threads. Basically, they will not seal up right and they will more or less freeze up and lock together. You can’t use white plumbing Teflon tape – this isn’t rated for fuel gas use. There is yellow Teflon tape made just for this purpose. You need a roll of it.
To attach the plumbing to the stand, I used 1/2" pipe hanging brackets. This requires drilling and tapping holes in the stand (which we will need to also do to mount the pumps, burners, and burner grills), so pick up a tap and die set. You will need the SAE version, and it should come with sizes from #6 up thru 1/4". You will also need cutting fluid to tap the holes. This is also sold at the hardware store.
The easiest way to put this all together is to screw together all the plumbing first. Wrap the Teflon tape around the male threads of the pipe, then screw it into the female fitting. Using a pipe wrench, tighten the piping together. Both the 5” nipples need to run parallel to each other. Lastly, attach your two valves to the plumbing. The knobs should face the same direction, and will face out the back of your stand.
Put the built up plumbing and valves on the back of your stand, and let the valves sit on the bottom cross beam. Line up the pipe hanging bracket and mark the holes out. I mounted mine using #8-32 x 3/4” screws. Get your tap and die set, and using the provided chart, get the appropriate drill bit (for #8-32 thread it should be the #29 bit). Center punch the hole locations, then drill the holes. Using the tap and cutting oil, thread the holes. I used three brackets and it’s pretty sturdy. Two brackets are common to the 5” nipples and bottom cross beam, and one is common to the 17” pipe and the leg of the stand.
Teflon tape the last male pipe end where you will hook up the gas, and tighten on your 1/2" FIP to 3/8” flare fitting. Teflon tape the fittings for the flex lines and put them on the gas valves. Note that if you build drip/heat shields for the gas valves, the best place to attach them is here, between the fitting and the valve. Once attached you might want to run a bead of silicone around them to keep the top water tight.
The last thing I added for the gas system was a hook to hang the coiled hose on. Here #10-24 x3/4” screws were used to attach it to the stand. The hook I used had a small tab that needed to be ground off prior to installing. After grinding it off I painted it to prevent corrosion, and installed it.
That just about concludes the gas system hook up, from the propane tank to the flex lines going to the burners, with the exception of the pilots.
ACME nuts with integral QCC fittings. The regulator and hose came with the black one, I had to put the green one on to get it to work. This was sourced from my old Bayou Classic SP4 high pressure burner that I was using with my old brew setup. Note the yellow teflon tape I used on the threads.
Shot showing the black iron tee, nipple to the gas valve, and the pipe bracket used to attach the plumbing to the stand. The valve rests on the stand, it isn't stood off from the stand. Again, notice the yellow teflon tape at all threaded connections. Also, toward the bottom left corner of the valve, notice the black cap with the flat head screwdriver recess. This is post mod from NG to LP. Under this cap are the bits you need to change to convert the valve from NG to LP.
Side view of the same showing the valve overlap onto the stand structure.
View of the second gas valve and black iron elbow.
Tail of the burner with the orifice fitting (that came with the burner) installed, with the air shutter (shiny metal cap) shown about half way open. You can see the dull metal that is part of the cast burner blocking about half of each hole in the air shutter. You rotate the shutter clockwise (in this photo) to open it more and counterclockwise to close it more.
Overall view of the gas plumbing. I used 3 pipe brackets, one under each valve and one at the bottom left near the tank hose connection fitting.
Close up of the fitting that goes from the black iron to the tank hose fitting. This is a 1/2" FPT (female pipe thread) to 3/8" male flared fitting.