The following post is an add-on to the article on Cavitation in Hydraulic Systems.
Last Friday I received an email from a Hydraforce technical service engineer (Thank you so much for it, Ben!) containing a link to an interesting and informative video, created by Sun Hydraulics, which allows you to literally see the phenomenon of cavitation and the accompanying sonoluminescence in a pilot operated piston type relief valve. That's not all, when I looked around the web and found the video on the Sun's Youtube channel, below the video there was a link to an extremely well written article on the subject, titled "Does Your Manifold Have Worm Holes?" (by the pen of Jeff Baker). If you want to know more about cavitation in restrictive valves - stop whatever you're doing and watch the video and then read the article (I am embedding the video and link to the article below).
I have only one problem with the video, only one, and I will tell you about it after I've described what I did when I saw it:
So, I watched the video - and my jaw dropped. I watched it once again, then once more, then I took the notes on the valves they used in the experiment (the RPIC and the RPIS) and read all the information I could dig out on these models and valve designs, after which I actually copied both the video and the article on my hard drive lest they disappear from the web in the future! That's how impressed I was! Although both the video and the article are very short, they are "straight to the point" and jam-packed with useful information!
Which brings me now to the sad part in which I tell you about my problem with it:
You can clearly tell that it took a lot of effort and ingenuity on the part of Sun engineers to devise the contraption shown in the video, conduct the experiment, and then shoot and produce a beautiful video. I wouldn't be exaggerating to call it a masterpiece. It ticks all the right boxes, it gives out useful tips, it encourages you to immediately dig for more information, it shows an extremely cool phenomenon of sonoluminescence in action, and yet - it has been on Youtube since October 2012 (five years at the moment of this writing) and has only clocked 4,479 views! The only phrase coming to my mind right now is - What the hell? How can this be possible? So much effort coupled with good information and priceless tips - and less then 5000 views in FIVE YEARS?!!!
Maybe it's just me overreacting, but I guess it once again proves that there simply aren't so many people truly interested in oil hydraulics, which does assign certain exclusivity to "our club" but which also makes the club seem so very small...
Be that as it may, if you want to see something cool and learn more about cavitation, I strongly recommend you to watch the video below and read this very interesting article: Does Your Manifold Have Worm Holes?
P.S. By the way, I've already said before that manufacturer catalogues are one of the best sources of good and free information you'll ever find. From this standpoint, technical information and tips openly published by Sun are among the best!