hello, i will appreciate if you share your input on the failure analysis on the O-ring leak for the AUV (autonomous underwater vehicle) application.
I will appreciate if you share my following additional inquiring:
What is your recommendation if I would like to trace down the leak path ( such as dye penetration or fluorescent liquid ) to simulate the leak via ingress pressure toward the interior pressure vessel?
Is there a way to figure out the root cause of O-ring leak by wear out mode ? the deformation ? or Elastomer Aging / Degradation (O-Rings & Energizers)? Or improper installation/workmanship?
If you’re trying to find an existing leak, then a positive pressure test may be more suitable. If soapy water doesn’t work, you could submerge the enclosure as it is tested. If you’re trying to identify the path of a leak, folded paper towels arranged around the enclosure may show you the path of the leak, if it doesn’t go on long enough to over-saturate them, and orientation is not changed during removal from the test environment.
Typically o-rings always work! Things that can lead to them failing are as you say - degradation of the o-ring itself from any number of reasons. The most common failure I see is a stray hair or bit of detritus interfering with the o-ring seal, or a completely “dry” surface that the o-ring seals against - it should have a light coating of silicone grease. This not only helps the seal, but extends its life by reducing friction.
Thanks for the response. Enclose is a test sample (DUT) to be used for the test. Here is my following inquiring for the clarification:
You propose to apply a positive pressure test may be more suitable to the DUT which mean to apply a positive pressure onto the DUT by placing a soapy water, folded paper towels arranged around the O-ring enclosure ?
Can you share more about what the test sample is here, and what your goals for testing are?
The advice I shared was the typical approach for finding leaks on Blue Robotics subsea enclosures / WetLink cable penetrators. It looks like you’re testing an o-ring that is acting as a face seal, and planning to use a simple noise-making leak sensor to indicate test failure? Is the goal to test many units? Your diagram is a bit hard to understand - is it a cross section of a rectangular or circular enclosure?
