Regulator Noise

[Fibonacci]

Upon disassembling it, we saw that the bearing had worn unevenly -- was even pitted, apparently through some grit, but we couldn't really be sure and found nothing that would cause that. It was replaced by the ruby and has been quiet ever since . . .

I looked at a used XStream 7mm ruby under a jeweller's loupe... a flawless surface though I guess you would expect that with a Moh's Scale of 9 (a diamond is 10).
Since incoming air to the HP seat has just been through the sintered filter, maybe the pitting in the original stainless ball was due to point loading by the actuating pin vibrating and causing minute fretting or spalled areas which then flake off?

What's the difference between brinelling, spalling, and fretting?

When discussing bearing damage — especially in the context of linear bearings — three terms that come up quite often are brinelling, spalling, and fretting.

www.linearmotiontips.com

 

[Regulated]

My brand new Mk21/S560 intermittently makes a “fffffrrrr” sound on gentle inhale in shallow water. Wondering if I should take it to the master tech at the LDS where I bought it.

 

[halocline]

I had my SP Evo S620 regulator serviced recently by an authorized SP service center. I do it annually, regardless. I now notice a loud "shrieking" noise when I inhale. It breathes just fine, but the noise is annoying. The SP service guy said it was normal and would eventually stop. Is he blowing smoke?

It depends on what you mean by 'shrieking'. There is a common issue in 2nd stages where the diaphragm buzzes when you inhale, and that almost always disappears when you're in the water. But there is also a not-uncommon harmonic whistling, almost like a musical instrument, in the 1st stage. That's from the piston and/or spring vibrating as air rushes past the edge of the piston, not that different than what happens when someone plays the flute. Usually you can dampen the vibration by making sure there's enough lube in the HP o-ring, and using a plastic shim to dampen the spring/piston contact. That noise is not likely to simply disappear when you're in the water, but it might go away over the course of a dive or two. Sometimes it happens with a full tank, then goes away as the tank empties, or vice versa. I'd use it on a dive and see what happens, if it doesn't go away then bring it back and ask the guy to do it over. If you get any flack for that, make a note to find a new technician.

 

[SaltyWombat]

@GameChanger, if you're talking about a honking sound from the second stage that only happens when the reg is dry and above water, then it's common and nothing to worry about. Call your dive shop and they'll explain it.

 

[Pressurehead]

I asked a young diver yesterday "did you hear the humpback whales singing during the dive", he said "what ! Whales singing? No I did not" , everyone else did, I am sure it was that rental regulator he was using [making weird sounds] masking the sound.
He is a new diver doing his [so called] advanced course final dive with an instructor one on one.
Could be other factors, nerves or what ever, My thought was "I don't like the sound of that regulator", and he sucked the gas out of that cylinder a little too quick, and seasick on the boat before splashing would not help.