Resonance

[fashionablylate]

Hello folks.
Today, I had a strange situation where I dropped down to about 50 feet, the temperature dropped about 15 degrees, and suddenly my regulator started to resonate with inhalation. It resonated for a few breaths, and then stopped, then did it again for a few breaths. I switched over to the octo so I could look at the primary, and everything appeared normal with it. I switched back to the primary, and it resonated for two more breaths, and then the sound / vibration disappeared for the rest of the dive.
I brought it into the LDS and asked them to take a look at it, and he said it's not uncommon for a regulator to exhibit this behavior with heavy use (I have 21 dives on it in three weeks since I bought it).
Anyone know what would cause it? Should I have it completely serviced, and rebuilt, or am I jumping at shadows?
TIA.
-Andrew

 

[rescuediver009]

What type of reg is this...?

 

[MikeFerrara]

Sherwoods do it.

 

[DA Aquamaster]

Many second stages will resonate a bit out of the water when the diaphragm is dry but it is unusual to encounter this for more than a breath or two under water.

Heavy use should not make a difference, that sounds like an LDS load of bull.

Some Sherwood second stages can often test very well on the bench with impressively low cracking efforts but then still breathe rather rough so that is a possibility.

Balanced piston first stages can resonate if the HP o-ring and the groove where it lives are not adequately lubricated and in borderline cases the problem can be transient.

 

[fashionablylate]

What type of reg is this...?

This is a Cressi Ellipse Titanium.
-Andrew

 

[neil]

Balanced piston first stages can resonate if the HP o-ring and the groove where it lives are not adequately lubricated and in borderline cases the problem can be transient.

In addition, springs resonate sometimes. The sound travels down the hose and sounds like it is coming from the second stage. Usually just rotating or flipping the spring over cures the problem. A job for a tech if you don't know how.

 

[sharkdiver00]

One of my regs (a US Divers micra adj) does it when it drops below 500 - 600 psi..., but I have not heard that from a Cressi.

Have you tried to contact them directly through their website? they are very good at responding.

Maria

 

[rescuediver009]

Yep, I had the same problem with a resonance once. Another potential solution, is to add a shime on either side of the spring (piston or diaphragm) the thinner the better, with a little lube and back off the adjustment. flipping works too.

Be careful if you haven't don it before. Nothing is funnier than having someone walk into a dive shop with their reg in peices.

 

[SubMariner]

Hello folks.
Today, I had a strange situation where I dropped down to about 50 feet, the temperature dropped about 15 degrees, and suddenly my regulator started to resonate with inhalation.

Andrew, I think you may be jumping the gun a bit on this one. If the problem persists, by all means take it back to your LDS & have them take a look at it. Otherwise.... :ignore:

DSDO,