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Acceptable vaccum test levels

Hello, I have been really struggling to pass the vacuum leak test for our newly purchased BlueROV2. I have re-made all the connections and sealings multiple times, changes all O-rings, but still, it seems that after the 15 minutes from 10 mmHG I get to at least 8, therefore not passing the suggested test.

Honestly, I don’t know what to do anymore, any clues if those levels are acceptable and what would be my next move or any tips and tricks to solve this?

Thanks a lot in advance
Emiliano

Hello,

It shouldn’t move.

That said, I suggest you test the pump by itself. Sometime, the pump leaks…

Cheers,
Etienne

Thanks Mate,

Yes i did, I have tested vaccum on the Battery enclosure, and that works fine! So the pump seems to be fine, unfortunately…

I guess I will try one last time to undo all the penetrators and then, worst case I will contact bluerobotics support.

:frowning:
Thanks again
All the best
Emiliano

How are you testing it? Just the main bottle by itself? If your pump is good, you might try both bottles at the same time. I think I’ve seen the battery cable leak, but I was having a few issues at the time and I can’t recall if it really was the battery cable, or something else. Anyway, I’d try both bottles at the same time with the T and see what it does.

Hi @Emiliano,

Are you using the T connector to run the lines to test both the 3" and 4" enclosure at the same time as specified? The wires themselves are not sealed, air will move from one enclosure to the other if only one is tested at time.

-Adam

Thank you all!

I tried with T connector, much better, but still loosing a bit. Last try i lost 1.5 (from 10 to 8.5 aprox) in 20 mins. :frowning:

How bad is that?

Thanks again, Ill keep trying.

Cheers
Emiliano

I think you should try and but your ROV in a bath tub and apply positive pressure to detect a leak. You will need to get another pump.

Wouldn’t this cause the end caps to blow out and flood the electronics enclosures?

Depends on how much pressure you put…

The 4 inch enclosure is secured on the cradle. You can also put threaded bar on the outside on the top.

The idea is to pressurize it before you put it in the water.

Following up on this old post. We had a serious leak during a recent dive, and the issue ended up being a leaky thruster penetrator. The potting epoxy apparently didn’t adhere to the inner wall of the metal penetrator fitting, allowing water/air to pass through an annulus around the epoxy plug.

We located the leak by taping the battery end caps on, pressurizing the case with a bike pump, and spraying soapy water onto the penetrator fittings.

We tried unsuccessfully to seal the penetrator with more epoxy. We eventually had to replace the entire thruster with one from our spares kit.

We still have a very slow vacuum leak (possibly coming down inside the surface cable jacket) but no more water intrusion so far.

I wish there was a reliable way to seal inside the jackets of all the cables that penetrate the electronics enclosure. It seems like if any of those cables get nicked, water could potentially get in to the enclosure.

I wish there was a reliable way to seal inside the jackets of all the cables that penetrate the electronics enclosure. It seems like if any of those cables get nicked, water could potentially get in to the enclosure.

That is the downside of using hollow cables and penetrators. The only foolproof way to prevent leaks from nicked cables is with wet-connectors.