Question reg makes vibrating noise

[Lorenzoid]

I have a HOG D1 (diaphragm first stage) that makes a sort of vibration. Any idea what is the likely cause? When I inhale normally on the second stage, the vibration is a few Hz (like "tat-tat-tat"), and when the LP inflator is used, the vibration frequency increases--makes sense, but what causes this?

It's sort of an academic question, as I'm going to do a complete service on the reg, and I'm sure that will fix the issue. But if it could be a damaged part, it would be educational for me to look for it as I disassemble the reg.

 

[James79]

(Bated breath first appeared in Shakespeare's Merchant of Venice in 1605. Using a shortened form of abated, which means "stopped or reduced," the phrase refers to people holding their breath in excitement or fear as they wait to see what happens next.)

but, but, but...... you can't do that in scuba!

 

[Jim Lapenta]

A harmonic vibration in the 1st is often one of two issues. The HP seat stem/stem o-ring not being adequately lubed or the lube has worn off. I've gotten a few in that clearly hadn't been looked at in years and the balance chamber was nearly dry of lube.

The other thing is the clear washers in the adjustment screw and diaphragm section. Lube is not sufficient to insulate the metal spring from the metal adjustment cap.

Over time it will wear down and be dissipated to the sides of the spring making it plain bare metal to metal again.

The D1 kits normally do not have the washers in them. The D2 and D3 kits do. The ones in the D2 kit are clear and the D3 are white. They are slightly different in thickness but that really doesn't matter because they are on the adjustment screw.

Swapping between the 3 1st stages works just fine because once the reg is ready to be tuned that thickness difference translates, MAYBE, into 1/32 or less of a turn on the screw.

I do prefer the white ones because they are easy to see when doing the rebuild.
I rarely swap mine because they don't really wear out and keep the new spares for when I get a D1 in that's missing one or both. As a result I always have a few in the bin where I keep orphan parts that come in handy when I get a reg that has been butchered and are not usually in the service kit.

The biggest reason for them to be missing is carelessness during the service where it was lost. And the tech just didn't bother to try and find a replacement.

As a side note when the Oceanic FDX10 1st stage came out the harmonic vibration was a big issue. What happened was that not only were they not using a washer to insulate the spring, but the OEM sourced a spring that was only ground flat on one end. If it went in with the unground end on the screw the reg would sing like an opera star on crack. Until they got new springs in and washers, the fix was to have the shop tech flip the spring over until the new kit could be installed.

 

[Jim Lapenta]

Just an FYI, I am not seeing the washer as a separate part that's available in my dealer price list. However, if you'll shoot me your address via PM I'll send you two via regular mail. No charge. Like I said, I always have extra and it's Christmas. So Merry Christmas!

 

[Centrals]

A harmonic vibration in the 1st is often one of two issues. The HP seat stem/stem o-ring not being adequately lubed or the lube has worn off. I've gotten a few in that clearly hadn't been looked at in years and the balance chamber was nearly dry of lube.

Same issue with Apeks.

 

[Lorenzoid]

Just an FYI, I am not seeing the washer as a separate part that's available in my dealer price list. However, if you'll shoot me your address via PM I'll send you two via regular mail. No charge. Like I said, I always have extra and it's Christmas. So Merry Christmas!

I'll take you up on that, Jim, since you sold me these regs. So many kind people on SB. @rsingler , whose reg service course was the bomb, offered me a couple in a post above, but he need not go to the trouble.