Gasket Help, Tips & Tricks

Hash and Stuff Extraction
, ,
1

Hello all!

I know there are a few gasket-related threads out and about, and I think I’ve read most of 'em though I’m sure I’ve missed a few. I wanted to start this one specifically to ask about any tips or tricks anyone may have in regard to seating their gaskets on their closed loop systems, with a slight focus on the material columns themselves.

I don’t know if it’s just that I suck :smiling_face_with_tear: , or if there’s something that wasn’t taught to me during my very brief training period, but for the life of me, I just can’t get the solid PTFE gaskets that the lead extractor at this lab has a preference for to work consistently.

Is it the gasket? I’ve read in several different threads here that solid PTFE gaskets are a PITA to work with, is that right? Is there anything I can do to get them to seal more consistently?

When I seat them, they seat well. The flatcap goes right on and the gasket slips into the grooves of the ferrule and seats fully. I vac the column down though the gauge isn’t too precise, and I don’t believe the vac pump really pulls a deep vac, or if it would even be a good thing to pull a deep vac, but regardless it seems like there’s at least a somewhat decent seal.

However, randomly/sporadically the lead extractor will have some columns leak on them, and obviously this infuriates them. I do everything as they taught me to, and they’re not particularly forthcoming, to say the least, regarding advice about this, so I figured I would turn to you wonderful folks, and kick off a gasket-tips thread!

1 Like
2

Just buy gylon gaskets from @BizzybeeTeam or @IlluminatedExtractor

4 Likes
3

If only I did the ordering :smiling_face_with_tear:

We even have old viton gaskets that seem to work more reliably than the solid PTFE (they are old after all, and we blast below -50). We had a few envelope PTFE/Viton, but they’ve all been tossed one by one as they begin to leak from mechanical failures/stretching/thinning of the ptfe till it tears.

All the gaskets seat well, definitely feels like the vac ‘catches’ quicker on viton or viton enveloped gaskets. But I’m Certain someone here has gotta have some bangin’ tips/tricks for Solid PTFE gaskets. Example question - Does it help to lubricate the solid PTFE gaskets, and if so, what’s the ideal lubricant? Ethanol? MCT?

4

Ive read that pure ptfe gaskets are meant to be, “single use”
If you want a lube for it, pick one you dont mind ending up in your end product.

4 Likes
5

image
image1064×1277 184 KB

12 Likes
6

I’ve read that they’re great for unions that aren’t gonna be opened a lot, wonder if that’s related?

Like, they’re obv not single-use, per se, but on the flip side they’re being used as material column gaskets in a sockless lab, and sealing relatively inconsistently.

7

Unlike viton, Ptfe is not an elastomer.

Once you nick it, or seal it up with debris in there, you’ve killed it.

You don’t mention using a torque wrench.

Use one. 15-20in.lb is appropriate for ptfe.

6 Likes
8

We do indeed use torque wrenches, and I always ensure the groove and gasket are cleaned with ethanol prior to seating.

Additionally, I’ve set up a bit of an adhoc cycle-count system for the gaskets as well, in a rough attempt to categorize and organize things. We’ve got a bucket for new gaskets, old/worn-out gaskets, in-rotation gaskets, and known leakers!

1 Like
9

Looks like @cyclopath was leading towards my recommendation.

I get that you cannot switch because they like the PTFE ones. Yes they are a PITA. Yes that’s why other people recommend others.

So you are cleaning your groove - are you also inspecting it? Are you inspecting your gaskets? I do gasket inspection using a microscope. Any nicks, tears, grooves, holes, divets, etc. That gasket is a no go and into the bin it goes. You could always start with new ones…but that might be too expensive for your boss.

Cleaning is important. You mentioned cleaning with ethanol - but what about all the other steps? Are you also doing a soap wash? A final rinse? Something with Alconox (or other gentle but effective cleaner?) - you have said that this system doesn’t have socks… I’m assuming that your gaskets are getting dirty and damaged. Cleaning all the stuff off them is important - just like inspecting them for damage.

I don’t know how often you change these out - I have some gaskets that get changed every day (I use new ones) and some gaskets that get changed every month (I inspect, clean, and replace).

Having both the equipment inspected to make sure that not on the groove is clean but that flange lips are also clean and free from divets, scratches, tears, etc is important when using PTFE - because like @cyclopath said this is not an elastomer so its not going to have the same give and smooshability that your “lead extractor” may have.

I might also just be a bitch and tell that motherfucker to build his own columns with his own shitty gaskets if he’s not interested in taking care of his own equipment. If he hasn’t already taught you about appropriate cleaning, inspection, and placement - then your boss is failing at his job of making sure you know how to do your job.

Lots of bosses out there like that. So look for somewhere else to work. If he’s a dick about leaks (which happen all the fucking time…that’s why we always fucking check for them) then he might be a dick about other things. Like professional development, laying you off when he wants to go on vacation, not caring about your personal safety, and generally creating an inhospitable work environment.

Some of those things you can live with - but choosing to go with a less flexible and safe gasket - making sure that your pumps are sufficient for the job (you implied either that they are not or that they are not working correctly) and making sure that your system indicators are fully functional and calibrated (you also implied that the gauges you are using for these safety checks are fucking bogus).

Sounds to me like you might be in a place that is unsafe. So while I think that appropriate cleaning, inspection, placement, and torque wrench tightening will help you get better seals. You might also consider the rest of your personal safety and ask yourself if its a good idea to be in a place with a big ass flammable bomb in it with systems that may not be in good condition to keep you safe. <3

Let us know if these things help!

7 Likes
10

If the person training you isn’t thorough, specific and articulate you are putting yourself in a fair amount of danger to appease their ego my friend.

5 Likes
11

Buna-n or Viton gaskets are the way to go for sealing surfaces that are constantly taken on and off. Solid PTFE is good for surfaces that are only disassembled like once a week.

2 Likes
12

The gaskets don’t appear to be damaged or packed with particulate/stained in any way (those that do I hang up in the leakers bin as they usually were leaking), at least they don’t appear so macroscopically, as we do not have a microscope in-house.

For clarity, while the position I applied for was titled “extraction technician”, at the moment I’m mostly just unpacking and packing columns for the lead extractor and assisting the other tech with post-processing, so I’m not even in the C1D1. The lead extractor could simply be loosening bolts in order to have a leak to report for all I know, but who would do that? Regardless, I’m not interested in participating in character assassinations :joy:

While it has been frustrating, I’m of the mind that they’re learning themselves (aren’t we all) and simply don’t have any ideas as to what to do/dont have advice to give because they dont know and struggle to admit as much professionally. There really isn’t much I can do in this situation beyond staying as professional as possible and doing my best to ensure that the column won’t leak when I sign off on it.

In regards to the pump comments, it’s just a shitty brake line vac pump we use to vac down the columns before chilling them. I’m sure that’s not the reason why ptfe sux as an unsupplemented gasket material :joy:

3 Likes
13

People. People would.

lmao Welcome to the industry my friend!

I’ve seen wooks sabotage a lot more because they were intimidated by an up and coming employee. Incompetent people don’t do well when competent folks come gunning for their jobs, or at least they perceive them as gunning for their jobs.

It is my understanding that pure PTFE will have memory after being cinched down and isn’t really meant for gasket applications which require frequent attaching and detaching. I could be mistaken but that’s certainly been my experience using PTFE gaskets. Always used Gylon or Viton depending on solvent and application.

You seem intelligent and articulate, be careful with poor management, especially direct training managers who are incompetent. If you are pinned for an accident that wasn’t your doing it will likely be the end your days in the industry regardless of actual fault.

7 Likes
14

It’s tough dealing with that sort of person. Especially if the lead doesn’t know any better than ptfe. You’ll be ahead of him in no time the more u kick around here lol

4 Likes
15

That’s a great attitude to have…unless you’re responsible for training people how to safely operate pipe bombs all day. Your manager should not be learning on the job as he’s training others. If he is truly ignorant of the basics like gasket assembly and how to instruct his subordinates to properly complete said task, then he likely only knows enough to be incredibly dangerous to himself and those around him.

5 Likes
16

…and they never seem to get that either.

Admitting “I don’t know” can really be hard for some folks. Ideally those folks should be avoided….

I really miss the GP I used to have who actually went and pulled a medical textbook off the shelve (in front of me) to figure out how to deal with the rare fracture I’d managed to inflict on my hand.

4 Likes
17

Does the lead tighten the clamps after they get cold during extraction and after vacuuming the system? My SOP calls for both and I get movement with the torque wrench every time. Before this I constantly had small leaks.

Does anyone pressure test their columns they changed gaskets on each run? We do this to 90psi and have identified leaky JIC and gaskets.

I do agree the biggest issue is PTFE gaskets. Idk anyone that uses those…

3 Likes
18

This is true everywhere but especially as others have pointed out when dealing with what amounts to pipe bombs all day.
The only application I’ve seen ptfe gaskets used in is large scale CO2 extractors that did not switch out columns, and even then the ptfe was only used on the bottom cap of the vessel that only got taken off ~1/month. And even then it usually required a new gasket. Constantly trying to reuse those things seems like a recipe for failure in my opinion no matter what. If you do have a chance to observe the techniques used during a run that would help immensely. As @Chewwie said a simple pressure test before a run (especially with those gaskets) and or tightening when everything is chilled and vacuumed could solve any of the smaller leaks. Good luck!

3 Likes
19

Thank you all so much for all the advice and tips!

I’m sure that it’s SOP to retorque all the bolts prior to a run, however I’m equally sure that a pressure test prior to introducing solvent to the column is Not in the SOP at the moment, and I will bring this up next time a leak occurs!

3 Likes
20

Actually put a straight edge on the “leaky” ferules…I had a 710snob that came in the door with 5 out of the 8 column ends (four columns) bent.

Took me a couple of weeks to wrap my head around the issue…I thought it was the crew I was training…one kid in particular too (impression was correct, but the damn leaks were not his fault)

1 Like