Otis’ 4” Column Condenser - RC / Dephlegmator

[OtisT]

Otis’ 4” Column Condenser - RC / Dephlegmator

After a long break from shop work I am finally starting work on my next build project with this RC / Dephlegmator for a 4” modular column. I want a condenser I can run as an RC just above a VM takeoff or just below a large open takeoff as a Dephlegmator, so it will need to be in a 4” spool open on top and bottom.

I want to keep total height to 8” and bought a new 8” tall spool for the body. I am using dual 3/8” copper coils with independent flow. I’ll connect one coil to a full port ball valve and the other to a needle valve for fine tuning.

I am keeping the output flow pipes separate for a few inches so I have a place to touch (or mount a temp sensor) so I can tell cooling water output temp.

Valves
My first challenge was finding valves I like. I found a 3/8” compression attach needle valve. Not full port, but it is cheep and clean for the build. (Full port needle valves are damn expensive). I think this valve will still give me the flow I need, estimated to be around 5 lpm. I use a smaller 1/4” needle valve attached to a 1/4” coil and can get 3.5 lpm through it, so the 3/8” version should get me where I need to be.

I am using a 1/8” full port ball valve, which has a 1/4” full port opening so it is a perfect match for this tubing size. 3/8” OD tubing is also sized perfectly to be threaded for the 1/8” FNPT thread on the valve. Very clean looking. The down side is that any leak or rework needed will be a major repair ordeal.

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