Piecing together a small SPD - what do you think?



No idea yust buy them at the hvac shop


Do the Yellow Jacket and Bullseye have different tips? I think I read the Bullseye is a 1/8" MNPT and the Yellow Jacket is a 1/4" MNPT.


Sensor is the same the yellow jacket just comes with an additional adapter


How is this for my SPD design to be made either in china or here in US?

I am toying with the Idea of going 45/50 main joints instead of 34/45… allow me to later on upgrade to a 12L flask if I ever wanted to but i thought this bigger bore 45mm might be too big and not function properly on smaller 500ml flask lol. Imagine a 45/50 jointed bigass spd head sitting atop a 500ml flask!

pretty simple. will allow for loose packing and use of Lab-Society’s structured packing tube within a tube. isolation adapter with the big bore 12mm ptfe stopple from what ive read the 4mm and 8mm are typical and 12mm ID is bigger than usual?


im sooo jelly of your ability just to blueprint anything you want made bro. That thing looks awesome and post up the supplier that gets this done for you cause ill be second on that list for something new. Thanks for doing this @square_root_pharms

and thats for showing how the two angles come together for 180 between the head and the isolation valve. That will be helpful retrofiting my current setup for a isolation valve too.


that 65 to 115 degree angle is custom. most chinese heads are either 60 degree or 75 degree. I wanted a faster fallout then a 75 degree but not the exact sharp angle of the 60 degree.

For a 60 degree head you’ll want a 120 degree angle at the isolation adapter. for a 75 degree head you’ll want 105 degree isolation adapter.


i have a 60 but didnt exactly understand the takeoff angle until you posted the diagram. I learned my lesson for the day. Thanks this will be extremely helpful in piecing together systems not only for me but anyone that see that!!!

edit…That should probably be in tricks of the trade thread as that is just awesome too…


this is with 45/50 SPD main joint. I think an SPD head to rule them all (500ml to 12L flasks) is asking too much?

anyone have any input on running a fatass 45mm joint/bore spd head on small runs (500ml -2L flasks)

The idea is that with packing i can take a big bore fat column head, pack it with rashig rings or similar packing and get good separation even on small boiling flasks.


Doesnt the isolation adapter need a valve to release your flask?


i didnt get that detailed lol it was a 10 minute sketch to get an opinion on the SPD head.


I like it. I may be interested if he’s got the setup you’re doing in 1l maybe 2l


1/8 " ? Man i hopethats on a T because If iT is the vapor path iT really is Tiny with all negative results on your vacuum depth


Ya I would think you would want to place it out of the vapor path. All these agilent 531 type sensors are 1/8 mnpt but many come with adapters or KF fitting adapters.


Does anyone use flasks with fixed/permanent thermowell?


I did but cleaning them out with first pass gunk is a agony once in a while


I have a few 1l flasks around here and some have the thermocouple built in. I like it for not having to take apart, but functionality is hindered


How would you describe the hindered functionality? as in the heat transfer through the thermowell is less accurate? or does the thermowell protude into the spin bar area? what would you change on the “Ideal” flask?


Less holes to use (lol), the thermocouple is stuck, so I can’t use it to pour in hot crude to start. And they go right where I would want the spin bar unless I tilt it. I will take a look later today


Hey everyone,

So the setup is coming together. I plugged everything in last night to make sure it works (minus my pump, I need to buy oil still) and see what else I need to get. A few questions came up during the setup (seems like good questions for @Dred_pirate @square_root_pharms @Killa12345 ):

  1. My chemglass cow doesn’t seem to be threaded for the bent gl connectors like the other connections are. Do I just need to attach the tubing to the barb? Or is there another adapter that fits that?

  2. I have the bullseye which I intend to put after the cold trap for vac. measurements. My distillation head has a port for a vacuum gauge. Is it necessary to have a second gauge at this location or will I be ok just capping it off and taking the reading after the cold trap? I keep seeing people reference a yellow jacket HVAC gauge, but the ones I keep finding are either analog or just a sensor - is this the cheap-o gauge people are referencing?

  3. Just testing the system I put a thermocouple between the mantle and the flask. It fit well and gave me useful readings. I also had a probe in the RBF neck. When SOPs reference the mantle temp, is it the temp that the mantle is at (i.e. the probe between the flask and mantle) or is that the temp of the solution (the probe that goes into the flask neck)? Should I just close off the second neck of the RBF and only measure the mantle temp?

  4. My 2021i has what I believe to be an “intermediate port.” What do I do with this?

  5. What oil are you guys using with this pump? A200?

  6. Is this a mist filter that is coming off of the pump?

I haven’t even powered this pump on yet, so hoping it works. The shop I bought it from has a DOA warranty so should be ok.


you pump looks very clean comparted to the ones i got…

  1. I think you can just hose those barbed fittings. They are barbed not for gl fittings.

  2. I think you can just cap off the second port, but 2 reading are better than 1. Knowing as much information will help you dial in everything faster.

  3. I dont know the answer to this question.

  4. Just leave that on the side.

  5. OIl i use is grade 20 from vacoil.com

  6. That is an automatic gas ballast. i dont really know how to use it. I heard if you remove that and plug it your pump runs quieter and better but i didnt do any of that. I ran it just like yours in the pic

Your system looks awesome bro. You should be proud. Wish my mantle was like that…wishing my whole system was like your bro.

Looking forward to the show.