Clarification regarding "environmentally sealed"

[ljpm]

Hi,

I have been looking at the different types of first stages and am a little confused. Aqua Lung states that "the balanced diaphragm first stage, by the nature of its design, is environmentally sealed" (see specs on Titan). This is not what I have been seeing for other manufactures. Aqua Lung states that the Legend is an environmental dry system that keeps water out of the main spring chamber. It seems to me that everyone EXCEPT Aqua Lung refers to a 1st stage that keeps water out of the main spring chamber as being "environmentally sealed" and balanced diaphragms which don't keep water out of the main spring chamber are not "environmentally sealed". Is this correct? Does the confusion stem from Aqua Lungs refusal to use consistent language with the industry? Or am I missing something?

Jim

 

[sea_ledford]

If it is a diaphragm 1st stage it will be a dry interior and therefore "environmentally sealed." Piston 1st stages typically have water intrusion into some part of the regulator by design. That is where I have seen the "environmentally sealed" marketing traditionally. In an environmentally sealed piston 1st stage the water ports will be covered with some sort of flexible barrier (usually a rubber ring) and the interior of the water compartment will be filled with a lubricant such as cristolube or tribolube.

The two types of 1st stages (diaphragm and piston) are just two different methods of transferring ambient pressure to the regulator so the intermediate pressure (hose pressure) is consistent regardless of depth. I'm not aware of any non-sealed diaphragm 1st stages.

-Chris

 

[tbone1004]

just a type-o from aqualung. Balanced diaphragms are not inherently sealed, though they can be. The over-balancing you see marketing by many of them is a design flaw in the sealing system that increases relative IP as you go deeper which is not necessarily a good thing.

The Titan description is confusing because it isn't actually a sealed regular, the diaphragm seals some parts of the regulator, but the spring is not sealed. It's very confusing on their site because the spec list for all of the regulators have different categories. If you are buying a diaphragm regulator, the sealing is certainly very nice to have and worth paying a few extra bucks because it makes cleaning much better.

 

[Jim Lapenta]

Actually with some mfg's it also relates to the main spring in the ambient chamber. The ambient chamber in a non sealed reg is exposed to water and anything in that water. I've seen regs come in for service with the main springs coated with crud. The diaphragms are covered on one side in it.

On a reg that is typically considered to be sealed the line I carry uses another diaphragm and cap with a sensing disc that transfers ambient pressure to the chamber area. The result is that when the disc is intact the entire interior, including the main spring is isolated from any contaminants.

Not all diaphragm regs are environmentally sealed.

Sealed regs are sometimes mistakenly referred to as cold water regs. The correct term is environmentally sealed. There are diaphragm regs that are not sealed and therefore not recommended for very cold water.

 

[ljpm]

Actually with some mfg's it also relates to the main spring in the ambient chamber. The ambient chamber in a non sealed reg is exposed to water and anything in that water. I've seen regs come in for service with the main springs coated with crud. The diaphragms are covered on one side in it.

On a reg that is typically considered to be sealed the line I carry uses another diaphragm and cap with a sensing disc that transfers ambient pressure to the chamber area. The result is that when the disc is intact the entire interior, including the main spring is isolated from any contaminants.

Ok, so from what I understand this would be regulators such as MK17 and Aqua Lung Legend.

There are diaphragm regs that are not sealed and therefore not recommended for very cold water.

I would therefore place the Aqua Lung Titan and the MK11 in this category. Correct?



Of course the reason I am asking is that I dive the Great Lakes / St. Lawrence River. And, although I have just started diving I hope to advance to the point of at least trying under ice diving. I therefore want to make sure I have an environmentally sealed 1st stage. as described by scubapro SCUBAPRO - First Stage Technology

 

[tbone1004]

correct. Mk17, All Apeks except for the US4, etc etc are all sealed. Hog D3, Dive Rite XT, Deep 6, etc are all viable options for sealed regulators. Poseidon does not require environmental sealing for their MK3 first stage which is a function of the overbalancing incurred from the environmental seals being incompatible with the Jetstream or Xstream, but it is approved for Navy ice diving which is a pretty strict requirement.