So I wanted to come up with some way to pump directly into my fermentation vessel from my chiller, while not having to lift anything in or out of the chest... The following is how I am doing it. (well, for now anyway...)
I ordered enough 24" long thermowells from www.stainlessbrewing.com
to accommodate one for each fermentation vessel. In my case, I have three. They are 1/2" OD x 24" long
with a compression cap on the end. Also, I ordered three full bore compression fittings
for the thermowell. As well as three 3/4"x1/2" reducing bushings
... I drilled out the center depression in the bung cap to 1/2 inch and it was a nice tight fit. Not air tight, but tight enough to stabilize the tubing and not rattle around.
Here you can see I used tape on all the threads to help seal it up and make it air tight. I threaded the bushing into the center of the 2" standard bung cap that came on the malt drum. (quite handy to realize those threads were there.)
I realized that if I had a compression fitting on both ends, my bung cap would be trapped... I set the compression rings aside and opted for the double stacked o-ring setup. Just slide on two o-rings and add the compression fitting and thread down.
Here it is assembled and adjusted to it's lowest profile possible. I don't have but just a few inches clearance above the malt drums and I don't want to build a collar for a ferm chamber, so I am very glad this proved to be low-profile enough to use in the chamber.
Here is the entire bung cap/thermowell setup.