Brutus 10 Build: The Gas System
In this first post in this series about my build, I described the Brutus 10 frame.
Now we’re going to talk gas.
This was actually the most challenging (and frustrating) part of the entire build. There are so many little parts that must work together and the inclusion of the solenoid valves threw another wrench into things. Not to mention that every connection point is a source for a leak and the consequences of spewing propane everywhere are not to be taken lightly.
Before I get too far ahead of myself, let’s start with an overview of how this thing works.
Propane comes out of the tank and into a low pressure regulator which brings the pressure down to 0.5 psi. Low pressure is needed for the Honeywells. If you’re not doing gas automation, you can run the whole thing at high pressure.
Some people have trouble with the gas beam because the propane tank thinks it’s not connected to anything. It responds by dialing back the flow, which reduces the power of your burners. The solution is to use a POL fitting instead of a QCC nut. The QCC has the safety valve which will lock up your system.
Propane enters the gas beam through a stainless steel flex line.
Burners and Orifice
I decided to go with the BG12 burners mainly for their size – they are about 6 inches in diameter. Many people use the larger BG14 burners which deliver more BTUs but they’re very big at 10″ across. If I were doing 15 gallon batches I may have gone with them but for my 6 gallon batches the BG12s are plenty.
Another reason for not using larger burners is that the Blichmann kettles have a stepped bottom, meaning the bottom is a smaller diameter than the rest of the kettle. To fit them, I had to bring the burner supports in to 10″ apart, meaning the BG14 flames would hit the frame which is not something I want.
The burners themselves are pretty simple – just a piece of metal with holes in it. It’s the orifice which is more complicated and what gave me some trouble.
The orifice is the tiny hole that shoots propane into the burner. Really, the only difference between high and low pressure burners is the orifice. Low pressure burners have larger orifices, and high pressure burners have smaller ones.
I am running on low pressure and there is a handy chart which lets you determine the orifice size from the BTU rating of your burner.
Since my burners at 50,000 BTU and I’m running at 0.5 psi (or 11″ WC) I determined that I needed a #45 drill size for the orifices. When I ordered the orifices from Tejas Smokers, I asked them to drill to a #45.
It turns out a #45 was slightly too large. The flame was weak and yellow, not blue with yellow tips like it should be.
It’s easier to make the orifice larger than smaller, but luckily I found a propane shop in Denver where the guy was extremely helpful with the entire gas portion of my build. He’s even built homebrew systems for friends.
He hooked up my burner and redrilled the orifice until the flame was perfect. He did all three orifices for only $20. You can see the difference below.
The lesson here is to start with a smaller orifice and then drill it out until you get the burner where you want it. The chart is only a guideline – it takes trial and error and the exact size will be different for every system.
The main feature of the Brutus 10 is the way it automatically regulates temperatures. It does this through a combination of a solenoid valve (the Honeywell) , pilot burner, digital controller (the Love), and thermistor (sensor). Here’s an example of how it works:
- The pilot burner is lit.
- The mash tun is set for 152°F on the Love and the sensor is placed in the mash tun.
- When the temperature drops to 151°F, the Love tells the Honewell to open which sends gas to the burner. The burner ignites because of the pilot.
- When the sensor reads 152F°F, the Love tells the Honeywell to close.
Here is a video of me testing out the automation with water. Pretty sweet.
Obviously a big part of this is the Honeywell valves.
There are really three parts to the valves:
- The valve itself (big square thing)
- The pilot burner
- The thermocouple
The pilot burner and thermocouple plug into the Honeywell as a safety device. If the pilot goes out, the thermocouple tells the Honeywell and the valve won’t open. It’s so you don’t shoot gas everywhere. The original Brutus 10 didn’t have this feature.
When you get the Honeywells you need to convert them from natural gas to propane by changing out a little spring. Then you attach them with 1/2″ MPT pipe. Since the orifice has a flare connection, you need to convert NPT to flare. I do this with the 90° fitting coming out of the Honeywell which is 1/2″ MPT to 3/8″ flare. A 3/8″ stainless steel tube then connects the elbow to the orifice.
The pilots were one of the bigger pains in the ass in the build. I mounted them to the burner support using corner braces and self drilling sheet metal screws. I was really happy with how well they mounted.
The annoying part was that they kept leaking. I attached the pilots to the Honeywell with 1/4″ aluminum pilot tubing and compression fittings. When I fired them up I got a flame around the base of the pilots, meaning I had a leak. It took a few tries to get it right, but every time you undo the compression fitting you need to cut the tube and attach a new one. I almost ran out of tubing, but they finally worked leak-free.
The thermocouple is an easy threaded fitting into the Honeywell.
It’s a little tight
If there is one thing I wish I did differently with this build it’s that I should have adjusted the overall stand dimensions to make it a little larger. The problem is that it’s a really tight fit between the Honeywells and the burner.
In Lonnie’s original Brutus 10 plans, he uses a small jet burner which doesn’t have the long tail on it like the BG12. You can see how I had to put the burner at an angle so it wouldn’t stick so far out the back.
Also, Lonnie used ASCO valves which are smaller than the enormous Honeywells. The Honeywells are too close to the burner for comfort, which is why I added the heat shield.
It’s not a huge deal, but if someone is copying this build I would advice them to make the stand a few inches deeper and lower the gas beam to give the Honeywells more room. The stand is pretty small overall, so it wouldn’t make it be a problem.
The control panel and electronics. Below is a part summary for the gas system with costs.
- BG12 cast iron burners x 3 (Amazon.com) – $48
- Honeywell 24VAC standing pilot gas valve x2 (PexSupply.com; SKU: VR8200A2132) – $120
- Honeywell pilot burner x 2 (PexSupply.com, SKU: Q314A4586) – $36
- Honeywell 24″ thermocouple x 2 (Pexsupply.com, SKU: Q390A1046) – $7
- BrassCraft 1/2″ x 24″ stainless steel flex line (Home Depot, SKU: 344497) – $12
- Marshall 2-stage low pressure regulator (Sourced locally) $30
- Needle valve/orifice for burners x 3 (tejassmokers.com, item #CVo125) – $60
- x 3 Stainless steel gas flex line 3/8″ x 12″ (plumbingsupply.com) – $30
- x 2 brass 90 degree elbow 1/2″ x 3/8″ (plumbingsupply.com) – $7
- Aluminum pilot tubing (Grainger part #5AU59) – $22
- POL fitting (Sourced locally) – $8
- 3/8″ x 1/2″ NPT adapter (Sourced locally) – $3
- Various 1/2″ black pipe – $4
- Corner braces and self drilling sheet metal screws for pilot mounts – $5
- Labor for drilling orifices – $20
- Total cost: $412