Regulator Noise

[GameChanger]

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?

 

[Jim Lapenta]

It might. Some regs will sing and then stop in the water or after they have been broken in. If it didn't do it before, something might be screwed up. The diaphragm may not be seated correctly or twisted.
This is also why, unless the reg is actually needing service, every time you take it in, you risk something coming back screwed up. And just because a place is authorized to service a brand, it doesn't guarantee they know what they are doing.

 

[Kupu]

If the first stage is MK25, an internet search for "MK25 squealing (or squeaking)" will bring up a number of discussions that may be helpful.

 

[GameChanger]

If the first stage is MK25, an internet search for "MK25 squealing (or squeaking)" will bring up a number of discussions that may be helpful.

It is an MK25.

 

[shurite7]

It is possible the technician didn’t put enough lubricant in the bushings of the Mk25. It may stop making noise over a few dives or it may not; you’ll have to dive it to find out. I’ve learned to use plenty of cristo lube in the bushings when servicing Mk25s. If the the noise does not stop you can ask the technician to take apart the Mk25 and re-lube the bushing.

In very rare cases this may not solve the issue. SP posted a bulletin showing one of the bushings can be cut in order to stop the squeaking noise. I’ve never had to go that far. Usually placing plenty of cristo lube between the two bushings and the o-ring works just fine.

 

[Bigbella]

Poseidon regulators would occasionally have similar issues, especially after half-arsed overhauls, often characterized as a "shuddering" in shallow water, frequently dismissed as just being the nature of pilot valve in Jetstream seconds -- a ready excuse for poor tuning; an easily-damaged valve (which I saw frequently); clumsy scratches to sealing surfaces; and even too high of an IP, more often than not.

Early XStreams had a funky whistling issue, if I recall, attributed by Poseidon to some weird "resonance frequency" issue between the ball bearing and actuating pin in the first stage, which seemed to have been solved in later models, after an industrial ruby, of all things, replaced the bearing . . .

 

[Fibonacci]

~snip~

Early XStreams had a whistling issue, if I recall, once attributed by Poseidon to some "resonance frequency" issue between the ball bearing and actuating pin in the first stage, which seemed to have been solved in later models, after an industrial ruby replaced the bearing . . .

I still marvel at that as a design solution... very cool.

 

[NeilA.]

I have an S600 and it does that. Only above water. Mine doesn’t really shriek, but certainly makes noise on the inhale, a vibration hummmmm.

it has only stopped when under water.

 

[Wants2divemore]

My MK25 / G260 (less than 1 year old, about 20 dives on it) also makes a noise when breathing out of the water sometimes too. It doesn't do anything funny under water and breathes fine.

 

[Bigbella]

I still marvel at that as a design solution... very cool.

I had one of those early models with the ball bearing; and while I occasionally heared a strange vibratory sound, I had always attributed it to the positive-pressure full-face mask that I had been using, and not my first stage.

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 . . .