Sciencemadness Discussion Board

Tubing for condenser hookup?

monolithic - 15-4-2021 at 13:09

I currently use yellow/orange latex tubing to connect my condensers to a recirculating pump. The flexibility and stretchiness is nice because I use an undersized tubing that stretches around the hose barbs and won't pop off and spray water all over. I don't like how the tubing has no rigidity -- the tubing will kink and collapse on itself if the barbs are horizontal (condenser upright in a reflux position.) Are there any tubing materials that will stretch over a barb but maintain some semblance of rigidity?

RogueRose - 15-4-2021 at 16:41

I'd take a look at vinyl tubing. They make various thickness's of the tubing and they also make some that has fiber reinforcement that makes the walls extra stiff. What I would do is look into some connectors that change the direction of the tubing, so if it needs to make a 90 degree turn, use a hose barb fitting. If you haven't worked with this tubing before, you can use IPA to lubricate the tubing and fitting. You can also use a heat gun on the tubing as it expands the tubing a little and allows to fit onto the barb easier then it contracts when it cools.


Here are some links to some quick connect fittings that I found to work very well. I put 2 90 degree quick disconnects on my condensor so there is basically no pressure on the tubing b/c it's not bending itself, the bend is in the fitting. I've found the water flows much better. If you have any questions about which fittings I found most useful, just ask. I used 3/8" and they were about $.6-1.40 each but they were almost $5 each at my local store.

https://www.usplastic.com/catalog/default.aspx?catid=855&...

https://www.usplastic.com/catalog/item.aspx?itemid=23885&...


Sulaiman217 - 16-4-2021 at 00:31

I am using PVC tubing sold as 4 or 5 meters roll. I use it for condensers. As well as a vent tube. I just determine how long tubing is needed and cut it.
Usually i dispose all used tubing after each synthesis and cut a new one.
I buy it in my country for around 9 dollars for each roll

Sulaiman - 16-4-2021 at 14:07

pvc tubing is cheap and works well.
One problem I find is that (plasticised, clear) pvc tubing sticks to the glass and often I cut it off rather than risk breaking the glass.
I like thick silicone tubing with large bore (not a very tight fit) so hose clamps are required,
more expensive but less stressful.

RustyShackleford - 16-4-2021 at 14:59

vinyl is quite good in my experience, flexible enough and suprisingly resistant to chemicals

monolithic - 17-4-2021 at 07:38

Thanks everyone, for the suggestions. Will look into PVC/vinyl. I currently use thick wall silicone tubing for vacuum, would reinforced PVC/vinyl also work for this? I want something less porous to solvent fumes (my silicone tubing stinks of solvent after several uses.)
Quote: Originally posted by RogueRose  
I'd take a look at vinyl tubing. They make various thickness's of the tubing and they also make some that has fiber reinforcement that makes the walls extra stiff. What I would do is look into some connectors that change the direction of the tubing, so if it needs to make a 90 degree turn, use a hose barb fitting. If you haven't worked with this tubing before, you can use IPA to lubricate the tubing and fitting. You can also use a heat gun on the tubing as it expands the tubing a little and allows to fit onto the barb easier then it contracts when it cools.


Here are some links to some quick connect fittings that I found to work very well. I put 2 90 degree quick disconnects on my condensor so there is basically no pressure on the tubing b/c it's not bending itself, the bend is in the fitting. I've found the water flows much better. If you have any questions about which fittings I found most useful, just ask. I used 3/8" and they were about $.6-1.40 each but they were almost $5 each at my local store.

https://www.usplastic.com/catalog/default.aspx?catid=855&...

https://www.usplastic.com/catalog/item.aspx?itemid=23885&...




That's a good idea, will have to pick up some 90 degree hose barb elbows. Have you ever had any leaks with the quick disconnects?

Fyndium - 17-4-2021 at 16:19

I use PVC or PU tubing, transparent stuff, the cheapest that is sold by the meter. ID diameter is somewhat specific, but if the end is heated, it will easily adapt to a larger barb. These tubes are also rigid so they won't kink.

Best anti-kink is to buy tube with thicker walls. I had two types of silicone tubing, the cheaper, thinner kinked all the time, but the thicker one never.

arkoma - 17-4-2021 at 18:17

black "vacuum" line from the auto parts is my favorite for piping condenser water. 1/4' ID I believe and heavy wall. slips right on condenser barbs, stays put, and comes without the usual terror of snapping the nipple. And there is no sag or kinking problem at all;.

S.C. Wack - 17-4-2021 at 18:31

Quote: Originally posted by monolithic  
the tubing will kink and collapse on itself if the barbs are horizontal


Roll up your sleeves...
Quote: Originally posted by monolithic  
some semblance of rigidity?


...then connect it to glass tube (flame polished of course).

Sulaiman - 4-5-2021 at 04:29

the 'best' choice of tubing is different for a permanent/long term setup (if you have space)
than where repeated set-up / tidy-up cycles are required.

Fyndium - 4-5-2021 at 05:03

I wouldn't say so. I would use same tubing for every setup, because it works and lasts, is cheap and lightweight but rigid enough to not kink at all. It actually needs a lot of effort to kink the tube to block the flow, I've faced this issue when siphoning something. Transparency also allows for easier lookup for any issues, like airlocks, dirt and so on.

If I had the space, I would have at least one permanent distillation station, perhaps (also) a rotavap if I were eager enough. Something needs to be distilled and your stuff and space is always used up for some other step.

Dr.Bob - 4-5-2021 at 05:04

I have used everything from thin rubber tubing (not ideal, as it can pop off or get aneurysms), to Tygon (fine for most work) to much heavier tubing for a few cases (cold temps or other odd things). I like Tygon (PVC tubing) for most cases, but black fuel line (viton) will do fine, it will last a long time, whereas Tygo gets brittle with time.

I have also used quick disconnects, they are ok as long as they lock together, as the friction fit ones can pop off, leading to floods.

If you have sharp turns, right angle connectors might work, but the more joints, the more leaks, in my experience, so I would use tubing and try to find a way to support it at the proper angle, like bring it from the back through the lattice work and they will hold it at the right angle, if you have enough tubing length to allow that. Short tubes often causes issues, so start with a long one, and as you remove it from a condenser, you can cut off the end, which wear out due to the stretching and are weak points.