Drysuit inflation valve freeze

[Richard Lundgren]

All equipment that distributes or transfer gas is prone to freeze if pushed in a cold environment. Last week, during a T1 class, the water temperature was ranging from 2 to 6 deg C. During the descent my drysuit inflation valve froze and jammed in an open position filling my suit. This have happened to me several times in the past so it was no big deal (the best prevention is really to accept that all gas delivery systems are prone to freeze thus making you expect the problem, not being surprised when it happens).

The following only makes sense if you are using an argon/suit inflation bottle to drive your drysuit.

There are two solutions to this problem, one being better than the other. I said before that I have encountered this problem many times before, jet it was probably two to three years ago thus I chose the not so smart solution to the problemJ.

When you notice that your suit is being auto inflated – as always when you encounter any problem, signal your team first! Then solve the problem. (Note: Can of course be performed simultaneously)

The not so smart solution is to simply un-plug the suit inflation hose thus cutting the gas supply to the suit. You will find that you solve the problem alright but at the same time creating a new less obvious one. If the problem is a result of a freeze in the drysuit inflation valve, this will be frozen in an open position, thus after disconnecting the LP hose enabling water to enter the suit. You will get wet and cold hence making this the not so smart solutionJ

The easiest and “driest” way of solving this problem is to shut down the valve of the argon/suit inflation bottle. I always configure the bottle in a way so that I always have easy access to valve. I dive with the valve opened only on full turn making close down a lightning fast and easy maneuver.

If you are running your drysuit from your backgas – disconnect the suit inflation LP hose even if this makes you a little wetter. If you can’t disconnect - then you need to go thru a full left post shutdown.

[Deep6]

Hey Richard,

Considering that we are dicussing cold waters, which leads to a frozen valve in the first place, would it not make sense to shut down your left post and treat the situation (from the team's point of view) as an lost reg?

You could now ascend safely, being warm and dry (which I consider rather critical if you are about to undergo deco in colder waters)? If there was a new problem with another diver, the third diver could always respond to it (as the team's position would have been modified to account for the lost reg), after which there should be enough time for the original diver to disconnect the hose, then re-activate his left post, trading a little water for an extra reg (*If* it were to come to that). At least he wouldn't be leaking for as long (and hence less cold)!

This sounds like an "internet problem", but I guess what I am aiming at is why accept getting cold and wet if you don't have to? That increases deco issues, tox issues, etc. (as you taught me :) ). Even if you forgot you had shut down your left post the emergency would be "no worse" than a unnoticed roll-off.

Just cruious about your reasoning to trade wet / cold for an extra reg, bro!

[jluttichau]

The not so smart solution is to simply un-plug the suit inflation hose thus cutting the gas supply to the suit.

Doesn't that depend on the rate of auto-inflation? What you are describing seems to only work with a low flow auto inflation due to the drysuit inlet valve being stuck in the open position but if you have an HP seat problem and get a higher flow rate the shutdown won't be quick enough to prevent an uncontrolled ascent?

Un-plug, stop the inflation fast. Shut down the argon bottle, and re-plug. You'll take in a little water but you won't risk an uncontrolled ascent if you can't shut down the argon bottle due to ineptitude or valve being frozen. The water you take in, will probably not be more then what is condensed inside the suit?


Cheers
Jonas

[Richard Lundgren]

I personally think that if you are using a separate suit inflation system, the best option is to shut down the valve of the suit inflation bottle. Takes about the same time as unplugging the LP hose with glows and cold hands.

The water that may enter the suit will be enough to make the rest of the dive rather unpleasant.

If I'm using the back tanks for suit inflation, disconnecting the LP hose is faster and thats why I would use this procedure here instead of closing the left post.