First stage whistling noise?

[skynscuba]

My GF just had her Mares Proton Ice regulator overhauled. I was trying it out in the garage, checking the intermediate pressure static and under load, etc., and noticed that the 1st stage makes a whistling noise when I breathe on the reg or purge it. Not my reg, but I hadn't noticed that noise before. Is that common?

 

[tfsails]

I can't remember--is a Proton a balanced piston first stage? Those have a tendency to whistle which is irritating as hell but other than that is not a big deal and won't affect performance.

My dusty memory tells me that a Proton is a balanced diaphragm, but it could be wrong. If it's a BD, I have no clue as to why it whistles.

 

[drbill]

Not suggesting yours is the same situation. I always dive with Mk10/G250's. One of my Mk10's started whistling every time I'd inhale. However, it still breathed easily so I didn't get it serviced right away (I was working in Belize and Honduras for two months).

When I finally took it in to our tech, he discovered there were "large" vertical cracks under two of the port plugs. Of course the whistling stopped when I replaced the core with a new one. I knew of similar problems with the Mk20, but not the Mk10.

 

[diveprof]

On older models of Sherwood regs this can be resolved by flipping the spring in the first stage over. I've had this occur on two occasions after servicing at the dive shop. Funny how womething as a spring being installed differently can cause such an annoying noise. I had a dive buddy had me his octopus once when this happened. There is no real up or down to the spring, but it does create nasty harmonics when installed the wrong way. Not sure if your's is a piston reg. If so, this may be the culprit.

 

[Greg Barlow]

The Proton Ice uses a balanced diaphragm first stage, and it is not normal for a whistling sound to be evident. It is normal to hear gas moving through the first stage as you inhale from the second stage, but it shouldn't be of a whistling nature.

You need to take the reg back to the shop that serviced it.

Greg Barlow

 

[Couv]

Not suggesting yours is the same situation. I always dive with Mk10/G250's. One of my Mk10's started whistling every time I'd inhale. However, it still breathed easily so I didn't get it serviced right away (I was working in Belize and Honduras for two months).

When I finally took it in to our tech, he discovered there were "large" vertical cracks under two of the port plugs. Of course the whistling stopped when I replaced the core with a new one. I knew of similar problems with the Mk20, but not the Mk10.

DrBill,

That is the first time that I have seen that anomaly in a MK10. Any idea what caused it or is it possible you bought a "Monday Lemon?"

c

Edited with my guesses:

My first guess would be that some reg tech used bolts in the hp holes for leverage and torqued them down too far. Next would be somehow, someone used either a hp plug or hose where the threads were over length.

c

 

[redacted]

DrBill,

That is the first time that I have seen that anomaly in a MK10. Any idea what caused it or is it possible you bought a "Monday Lemon?"

c

How about a little over zealous use of one of those poorly made regulator handles?

 

[sulaiman]

take back to the tech guy and ask him to flip the seat

 

[DA Aquamaster]

I hear the "Flip the spring over" solution to a whistling piston first stage every so often.

To flip the spring you have to remove the piston and in removing and reinstalling the piston, the piston stem usually gets re-lubricasted or at least the lube on the high pressure piston stem o-ring gets redistributed.

That is the key as what matters is not the orientation of the spring (as there really is no up or down on one) but rather the lubrication of the piston stem o-ring. Inadequate lubrication causes the piston to stick and vibrate slightly rather than move smoothly and that slight vibration results in the harmonics you hear.

On a diaphragm reg there are more options, but inadequate lubrication of the seat stem in the seat carrier and its associated o-ring and backing o-ring would be the most likely candidate and would produce the same type of vibration.

 

[Couv]

DA,

Thank you for validating my suspicions. The "flip the spring" fix never made a lot of sense. In addition to possibly pushing a bit of lube onto the piston stem & o-ring, the hard seat may also take a slightly different bite into the soft seat. However, I think your harmonics theory hits the mark.

c