Mysterious 'death rattle' in B2 first stage

[DocCarl]

Hi.

One of my regular dive buddies is having a rather peculiar issue with his B2 first stage. The regulator intermittently makes this weird, rattling noise. It's probably just easier to check out the video. If you turn up the speakers, there's really no way to miss it.

http://vimeo.com/m/73744427

Anybody else experienced this?


Thanks,

Carl

 

[j2s]

Does it only do it when your buddy inhales ????......

 

[DocCarl]

Yes, it's only on the inhale, and appears to be totally random.

It was a fluke that he managed to catch two in a row on the video, although this happens several times in a dive.

 

[Scared Silly]

Chattering is typically due to airflow being interrupted. Could be in the first stage or because of something in the second stage.

What is the service history? Just serviced or in need of service? What is the IP?

 

[DocCarl]

Purchased less than a year ago, approximately 50-ish dives.
No service since purchase.

He did take it back to the dealer after noticing this, but they were not able to offer any assistance. I have not personally checked the iP on the reg yet

 

[chillyinCanada]

Why couldn't the dealer offer any assistance?

 

[RJP]

Why couldn't the dealer offer any assistance?

Probably couldn't replicate the problem, if it happens at depth and "only randomly"

 

[SeaCobra]

Is this a sealed first stage? The most likely culprit is a misalignment in the first stage of the piston, spring or seat, which is difficult to do in this design. Also the piston shaft bushing or o-ring could be out of kilter. If it were me I would have an Atomic tech check the IP (doubt you will find anything amiss here) and then disassemble the first stage, inspect all internal parts, replace anything suspicious, lubricate and re-assemble.

 

[Scared Silly]

Is this a sealed first stage? The most likely culprit is a misalignment in the first stage of the piston, spring or seat, which is difficult to do in this design. Also the piston shaft bushing or o-ring could be out of kilter. If it were me I would have an Atomic tech check the IP (doubt you will find anything amiss here) and then disassemble the first stage, inspect all internal parts, replace anything suspicious, lubricate and re-assemble.

Getting something out of alignment is difficult but I have seen a couple shims not get into the correct position. I have pulled apart a couple regs (two of my own) where the shim is all managed.

I typically put a shim on both ends of the spring. A few times the shim that is between the spring and body or the spring and piston did not get in place correctly. I attributed this to the assembly process. Here is how I do it, with body upside down, I place the shim into the body with a little Christo-lube on it which makes it stick. I then insert the spring followed by the shim, and piston. Again with a bit of Christo-lube on the shim.