Originally Posted by Ricochetbrew
I noticed that you used threaded ports. Was there a reason you chose these over ports for tri clamp fittings? Was it just a cost issue? Additionally my current brew kettle has a ball valve and a weldless thermometer. What is the necessity of a three port kettle? What do you use each port for? Thank you and forgive my ignorance.
No worries. Nope, wasn't for cost. If it was a cost move, I'd have sourced my own keg and then drilled it out myself for weldless bulkheads. I went with threaded fittings for flexibility. If I went to go for tri's later, they can be adapted. I don't see myself going that way, but I like to plan for the "just in case I want to..." moments. Here's one that might help:
The left 1/2" full coupler is for the valve. On the outside of it, we thread in a "close" or 1-1/2" nipple, then a 3-piece ball valve, then connect to your tubing using your preferred method (I'm going with 1/2" NPT to 1/2" barb, then clamp with an oetiker). On the inside of the keg, I'll thread in a 1/2" NPT to 5/8" dip tube.
The top 1/2" half coupler is for the 3" thermometer. We don't want the probe too close to the bottom or we'll get skewed readings. If you'd prefer a 2" thermometer, you'll probably want to go with a 1/4" NPT instead.
The right 1/2" half coupler is for the sight glass. Most sight glasses connect with a 1/4" NPT fitting because they don't need much flow. However, having 1/2" NPT and using a reducer gives future flexibility. You can do a 2-port version where the thermometer and sight glass use the same port if you prefer, but then it has to be at the bottom and you introduce the skewing of the thermometer.
Bobby M sells all of these fittings over at Brew Hardware. That's where I bought mine. He has written a very thorough article on keggle fittings
and positioning the welds, plus a good deal of YouTube videos out there if you get bored.