Atomic second stage design

[James-S]

Quick question about Atomic Aquatics second stages if anyone knows the answer...

The second stages have a "seat-saving orifice", meaning that the seat and orifice are only in contact when the regulator is pressurised. However, would this then mean that if the second stage were depressurised underwater, than water could then leak into the second stage, through the LP hose and even into the first stage? This would be a concern is it was being used as a stage regulator, where it may spend long periods of time underwater with the pillar valve turned off. Water ingress would then lead to internal corrosion, which is obviously a bad thing. Is this the case, or is it designed so that even when depressurised, water would only be able to get in if the purge button was pressed?

Thanks in advance for any information

 

[Scared Silly]

Water can only get in if the air in the hose is displaced.

 

[wmspdi]

In theory, yes. The seat is spring loaded and moves slightly back from the orifice when air pressure is removed to reduce engraving. A small amount of water could work it's way into the first stage if the regulator was depressureised under water, say during dual tank valve drills or post dive cleaning. Always clean Atomic regs under running water by hold the first stage higher than the second. If soaking leave the first stage attached to a tank under pressure (a small pony bottle will do). However by reapplying tank air pressure to the first stage after cleaning, and then purging the second stage you would blow any water from both first and second stages plus any lines before storage.

I use a Z1 on a pony bottle and just turn on the air before the dive to apply pressure to the second stage seat. If using the Z1 on a stage bottle apply tank pressure to close the seat in the second stage, then turn the valve off leaving intermediate pressure in the low pressure second stage air hose. The valve is closed, the seat stays closed, you won't bleed air from your stage bottle and water will not creep back through the seat. Not a big concern for me.

 

[Hatul]

If the regulator is not pressurized and you dive with it water is bound to enter under pressure. I have the ST1 and and it is something you need to be aware of. It's not a good choice for a stage reg.

Adam

 

[James-S]

Thanks for the information everyone, answered my question perfectly

 

[cbrich]

If you are using Atomic regulators, or matter of fact any regulator, for a pony, stage, or Deco reg; you should pressurize the reg before the dive. I make it a habbit to turn the valves on my Deco bottle during the dive to make sure they stay pressurized.

 

[Hatul]

If you are using Atomic regulators, or matter of fact any regulator, for a pony, stage, or Deco reg; you should pressurize the reg before the dive. I make it a habbit to turn the valves on my Deco bottle during the dive to make sure they stay pressurized.

I'm not a technical diver, but I would think if you leave a stage bottle unattended you'd want to have the valve turned off to avoid the risk of finding it empty on the way back?

 

[Scared Silly]

I'm not a technical diver, but I would think if you leave a stage bottle unattended you'd want to have the valve turned off to avoid the risk of finding it empty on the way back?

There is a difference between leaving the valve on and pressurizing the reg. One can turn the valve on, thus pressurizing the reg. If one turns the valve off the reg is still pressurized and the seat will be sealed. If one hits the purge the reg is no longer pressurized and the water can then enter the reg.

As such, for deco, stage, and any other bottle one does exactly as you note: turn it on, pressurize reg, and turn it off.

 

[Hatul]

There is a difference between leaving the valve on and pressurizing the reg. One can turn the valve on, thus pressurizing the reg. If one turns the valve off the reg is still pressurized and the seat will be sealed. If one hits the purge the reg is no longer pressurized and the water can then enter the reg.

As such, for deco, stage, and any other bottle one does exactly as you note: turn it on, pressurize reg, and turn it off.

That's a way of dealing with it. When I dive solo I take a pony tank (slung on the right) and keep the valve open. My thinking is that if I need it I don't want to have to fiddle with it before I can breathe. That would be my choice with any bailout bottle which is for emergencies. For deco or a stage bottle, which is used electively your method makes sense.

Adam

 

[redacted]

That's a way of dealing with it. When I dive solo I take a pony tank (slung on the right) and keep the valve open. My thinking is that if I need it I don't want to have to fiddle with it before I can breathe. That would be my choice with any bailout bottle which is for emergencies. For deco or a stage bottle, which is used electively your method makes sense.

Adam

It is a knob, not a zipper. Practice.