Knee knocker love- I bought a CK-2-B16

In preparation for the first trial run of the CK on propane, I need to repair the broken line at the discharge of the float.  I decided to spin a copper sleeve to make a better connection.  The tube is 1/2" and the line is 3/16".  My plan was to cut off the very end which is broken, slide my adapter on, and silver solder it.  I'm not even sure I need to cut the end off.  I might just slide it over as is; a quick look at a cutaway view makes me think to leave he tube alone.  What I'm not sure about is what kind of heat damage can I do to the innards, like any seals or what not.  If I wrap a wet rag around the top of it and focus my soldering to the bottom, should I be okay?  I would be cleaning everything up much better, of course, and probably run a new section of 3/16".

Most of my experience is with brazing, but I have done some silver soldering with stainless steel sheet metal.  I'll have to do some practice with some copper to steel parts.  I think I will cut the adapter I made down to just 3/8" to 1/2" and solder towards the bottom. 

Yes, it takes a lathe.  I have a small Nova wood lathe I bought mainly just to spin parts for my fridge projects.  It is actually quite easy to do, but like anything takes some practice.  I bought some collets to support various size steel rods so I can get good tight fits to pipe and tubing.  This piece was just a section of scrap 1/2" hard water pipe.

I want to make my own accumulators, wyes, and maybe filter/driers.





An experimental accumulator.  This one is probably going to be used for the heat pump in my lab this week.

Wow, I second that emotion.  Very impressive work!  You make it look easy but I know it isn't.  Very pretty.

Inpressive didn't know you could do that but I'm no machinest !  

I've always been a fan of metal spinning but I've only made a few pieces that way over the years.

Back on track:  I tried to cut the spun adapter down to just cover the end of the float down tube, so I wouldn't have to apply heat very high.  Unfortunately, I was not very careful when I reduced to the 3/16", after spinning down to 1/2".  I couldn't make it fit, so I gave it another go.  This one fit just fine, and so I went ahead with the rest of the work.  Splitting the bypass tube on the low side allowed me to make a low side service port.  Later, if everything goes well, I'll turn the high side part at a 90 so it is parallel to the low side and put a service port there too, clamping them together with some sort of copper band.

I had intended to braze everything except the adapter, but once I got into soldering, I figured just do that the whole way, as I might have to disassemble some of it, and really, silver solder should be good enough for this work.  I usually braze everything, but many HVAC technicians solder.  I don't know, not my field.

Anyway, I was going to swage the 3/16" piece, but my crappy Harbor Sheight flaring/swaging tool doesn't have any groove in the 3/16 hole, so it slips.  Works well for every other size.  I just cut a length of 1/4" tubing to act as a sleeve.  Worked fine.  The rest is self explanatory.

Pressure tests and evacuations went well, although the initial purge of nitrogen produced an aweful acrid so2 stink.  It burned my throat.  I can't imagine what a leak would be like in a charged unit!

I've since charged the unit with propane.  I'm not sure the size because I don't currently have scale to weigh the 30lb capacity recovery tank I decided to use for such a large charge.  I will get one.  I charged as a liquid to the high side, with a heater on the tank for added pressure.  If I opened the valve suddenly, I could hear something knocking around inside the float chamber, i assume was the float ball, it never opened though.

I charged a little bit of liquid to the low side header before switching to vapor and starting the unit.  It has been humming along for 30 minutes now.  The high side is at 160 lbs (94 degrees F saturation), and the low side at 10 inches of mercury.  The float won't rise.  I have a magnet on the top/side (1/2" thick, 2" diameter neodymium) and I've rapped on the side a few times, but nothing so far.  I can hear a watery noise in the compressor I assume is the oil pump.

Going to call it quits for the evening here soon, I'll leave the charge in it overnight and hope the propane will loosen up the float, but I doubt it.  If I can't make any progress, I am seriously thinking about running some coil flush through the float chamber, but I'm not sure yet; need to do some research.

Very good. I hope that you can get the float to open. I'm excited to see how this works out.

Oh, and welcome to the club. Now you know what SO2 smells like and know that it can burn you! I've never smelled more than a whiff like you but that was enough for me. Travis on the other hand knows what it is like for a small unit to leak it's full 2 pound charge into the house. No bueno.