Pneumatic connection

[jua123]

Hello!

I want to use a pneumatic connection, the closing and opening valves will go inside the hermetic enclosure, the question is, what would be the best option to cross the enclosure from the water to the enclosure with a pneumatic tube?
This piece would do its job if we add an O-ring ??? I need the pneumatic connection to work at 50 meters.

Thank you.

[EliotBR (Eliot)]

Hi @jua123, welcome to the forum

@jua123

what would be the best option to cross the enclosure from the water to the enclosure with a pneumatic tube?

That’s a very interesting question - I’ve passed it on to our engineering team in case any of them have experience with pneumatic connections

@jua123

This piece would do its job if we add an O-ring? I need the pneumatic connection to work at 50 meters.

That’s unclear, and likely not something we can give a definitive answer to - you’ll likely need to do your own testing. I wouldn’t suggest mounting something like that to a standard enclosure endcap without a face-seal o-ring. I’m also not sure whether the material of that fitting is suitable for submersion in water/salt water - it may have corrosion issues.

What size is the outer diameter of the pneumatic tube? I’m curious whether it could perhaps be used in one of our WetLink Penetrators, although there may be some issues with waterproofing because it likely can’t make use of the jacket seat that a normal cable is supposed to sit against. 50m is significantly less than the 950m rating of a properly installed WLP, so it’s at least not inconceivable that it could work.

[EliotBR (Eliot)]

@EliotBR

I’ve passed it on to our engineering team in case any of them have experience with pneumatic connections

Following up on this,

@emillerstead

I’ve done some impromptu sealing onto soft lines / hard tubes with WetLink Penetrators - you’d just have to make sure you’re not clamping down too hard on the pneumatic tube, that would constrict it too much. But it should work/seal fine.

Otherwise I would recommend Swagelok fittings, that would be the go-to for something very reliable.

[jua123]

Thanks for the welcome and your answer.

The part I show in the photo is 316 stainless steel which is supposed to be for marine applications. You are right, I have to try it but I wanted to post the topic to see if someone knew something. That piece would have two O-rings, one on the inside and one on the outside. The diameter of the pneumatic tube is 4mm but I could use 6mm or 8mm without problem, since if I have a flow problem I use a regulator, the cable I have for example is hard, the material is polyurethane, would it work for WetLink? I see that the engineers say yes, but for air there are other cables such as rubber that could work but I would have to test to what extent it compresses the air flow and if the WetLink seal would work with a hollow cable, well what in the end I understand that I have to try and test and retest, but it would be very interesting to use WetLink for pneumatics apart from electric cables, hopefully the engineers could do a test in water, confirm it, something similar to Cable WetLink . The coincidence that the Swagelok company is near my house and I did not know it, I see that they have very good material, I will also ask and publish the possible combinations.

Thanks for your work.

[EliotBR (Eliot)]

@jua123

hopefully the engineers could do a test in water, confirm it, something similar to Cable WetLink .

I’ve passed this on internally for you, although I can’t guarantee we’ll be able to allocate the time for testing/collecting the required data, so we likely can’t provide such a guide in the near future at least.

[jua123]

Wow! Thank you! I’m going to continue testing to see which is the perfect combination.