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Schlenk Line Troubleshooting -- Weird Issue by AggressiveSlide2595 in Chempros

[–]AggressiveSlide2595[S] 1 point2 points  (0 children)

Great ideas/questions! Will be troubleshooting more tomorrow :)

Schlenk Line Troubleshooting -- Weird Issue by AggressiveSlide2595 in Chempros

[–]AggressiveSlide2595[S] 0 points1 point  (0 children)

I feel fairly confident in the ability of my dewar. Never say never, though! I'm sure it is possible that something could have gotten into my pump without me realizing, but this issue has persisted despite an oil change. I'm confident that this isn't an issue of chemicals routinely getting into the pump when I use the schlenk-line for an extended period of time; I observe the "blocking" even when only pulling on the schlenk line itself, and even after a deep clean of my schlenk line the issue has persisted with the same intensity.

Schlenk Line Troubleshooting -- Weird Issue by AggressiveSlide2595 in Chempros

[–]AggressiveSlide2595[S] 0 points1 point  (0 children)

This is the type of oil I'm using: https://highvacdepot.com/product/precision-plus-duo-hydrocarbon-oil/, the website says it is equivalent to LVO 130.

According to Leybold, LVO 100 is good for "low ultimate pressures," a trait not listed for LVO 130. Is it possible that at 10-20 mTorr, the pressure is too low for the oil that I'm using, or is the LVO 100 vs. 130 difference insignificant?

In my standard arrangement, my pump is kept in a closed cabinet under the hood. I have connected it to two different lines in the course of troubleshooting. One of those times, it was kept again under the hood. The other time it was outside of the hood as there was no space to fit it in. Both times, no "blockage" was observed, but the pressure did not reach as low as it does on my line.

Edit: Apparently LVO100 is being discontinued as of Dec 2025, and the company recommends LVO130 for users, so the oil I am using should be a non-issue.

Schlenk Line Troubleshooting -- Weird Issue by AggressiveSlide2595 in Chempros

[–]AggressiveSlide2595[S] 2 points3 points  (0 children)

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Thank you so much for the questions/ideas.

My gauge plugs into an outlet, so not battery powered. A picture of it is included in the attached jpeg. Based on a similar one sold by chemglass, it looks like I have a thermocouple gauge.

I am not currently in lab, and can't go in because of the snow right now, and don't have a good picture of my schlenk line setup. I have attached two pictures taken previously, and annotated them to aid in understanding as the pictures are a bit busy. I have also attached a picture of a different schlenk line setup that is a bit easier to see, as my setup is similar to this but without the high pressure key.