BC Power Inflator, do we really need it ?

[elan]

This was one part of your question that I didn't address in my original post. I think I see where you're going with part of this thinking and that is the reasoning that the rapid filling of a BC in cold water can lead to a free-flow from first stage freeze up.

I don't have much experience in extreme cold water diving, but I would try to mitigate the risk of such by:

1) making sure my regs had cold water service kits
2) carrying some sort of redundant air source, whether it is doubles, or a slung stage, etc.
3) choosing an inflator that has a slower fill rate

Remember, diving is not about taking risks, it's about managing those risks that are inherent to the sport as best we can.

While I was writing my second response you actually wrote yours thanks.

1)Yes sorry for not expressing my question clearly, I was assuming that it is mostly cold water related. And when the free flow is not a question whether it will happen or not but when it will happen.
2) that's automatic for me.
3) Thanks for bringing this, I did not know those exist but I would probably pick one for my dry suit.


For warm water diving I would probably not bother as chances it will freeze are lower, I will be bare fingers and everything is brighter and warmer.

 

[elan]

Remember, diving is not about taking risks, it's about managing those risks that are inherent to the sport as best we can.

Yes, mitigating them is part of the strategy

 

[Cave Diver]

Thanks about all your good points. I think with the maintenance one can prevent it happening but with the cold water and elevated chances of the inflator malfunction due to freezing or 1 st stage freeflow makes me thinking about that. Now if we talk about freezing cold water we assume that the person will have a another buoyancy device that is a dry suit that can be used as a temp buoyancy device in case an instant lift is required. This can also freeze open but at least in case when a separate bottle is used for inflation the chances are lower as the reg is not loaded at all. Cave Diver I cannot actually agree with you that the issue can be managed easily. while for warm water divers that can be a breeze in cold water most likely it will mean the connector freezes up and in thick gloves there are much less chances to disconnect the connector as of my understanding.

How would cold water affect this situation in your opinion ?

The freezing is likely to occur in the first stage, rather than at the connector. I haven't heard of any issues of the quick disconnect freezing, but I'm sure it's possible.

If you can't disconnect the inflator, you need to shut down the valve ASAP, so hopefully you're proficient in valve drills. You should also be practiced in venting the BC. Having to shutdown a valve and the excessive gas loss that would be likely by venting the BC during the shutdown process are the reasons why this type of diving is recommended with redundant air sources.

Whether or not it can easily be managed depends on whether you are familiar with the types of emergencies that can arise and practised in the methods for dealing with them.

 

[elan]

If you can't disconnect the inflator, you need to shut down the valve ASAP, so hopefully you're proficient in valve drills. You should also be practiced in venting the BC. Having to shutdown a valve and the excessive gas loss that would be likely by venting the BC during the shutdown process are the reasons why this type of diving is recommended with redundant air sources.

Whether or not it can easily be managed depends on whether you are familiar with the types of emergencies that can arise and practised in the methods for dealing with them.

Yes what you have described that's exactly what has to be done. I have not get to that point yet, will be addressing this within my next 30-40 dives, but it is still a complex process which I was thinking can be simplified. Though you have to do it in any case in case of 1st stage free flow at least you do not have to fight buoyancy as well.

I did spoke to some people and they told me they do that (not connecting the BCD) when the risk of freezing is high. Some when diving single tanks do not use BCD at all and add air to the suit just to remove the squeeze.

But in any case the more opinions are provided the better for everyone

 

[Cave Diver]

I should also take the time to mention how important proper wing sizing/balance weighting can be in this equation as well. Assuming that the wing is not excessively large, you should be able to control your bouyancy from taking on a runaway ascent by deep exhalation and shallow breathing.

Also, prevention can go a long way by recognizing the potential for freeze up in cold temps. Try to avoid long blasts from your inflator and from operating two LP devices at the exact same moment (reg/LPI or reg/drysuit).

I'll leave any further cold water advice to those who have more experience with that than me.

 

[elan]

The freezing is likely to occur in the first stage, rather than at the connector. I haven't heard of any issues of the quick disconnect freezing, but I'm sure it's possible.

The chances are greater when you ice dive and take your rig to the surface when the temp is lower than 0c (32f). In this case it's guaranteed being frozen if there is some moisture inside. Some people just leave the rig in the water while making their SI.

 

[Cave Diver]

Yes what you have described that's exactly what has to be done. I have not get to that point yet, will be addressing this within my next 30-40 dives, but it is still a complex process which I was thinking can be simplified. Though you have to do it in any case in case of 1st stage free flow at least you do not have to fight buoyancy as well.

It's good that you're thinking through scenarios and potential failures points. As the saying goes, luck favors the prepared. Diving with the hose disconnected, IMO, would be preferrable to diving with no hose at all. But I'd still personally prefer to be aware of the situations that might cause a freeze up and try to avoid them through technique rather than disconnecting hoses.

 

[elan]

I should also take the time to mention how important proper wing sizing/balance weighting can be in this equation as well. Assuming that the wing is not excessively large, you should be able to control your bouyancy from taking on a runaway ascent by deep exhalation and shallow breathing.

Also, prevention can go a long way by recognizing the potential for freeze up in cold temps. Try to avoid long blasts from your inflator and from operating two LP devices at the exact same moment (reg/LPI or reg/drysuit).

Yes all that you have mentioned is helpful. In the case of free flowing my buddy had he has noticed that his LP inflator started pushing small bubbles, shortly after that his second stage would not stop giving air.Lucky him he did not press the inflator button that time.

 

[Cave Diver]

The chances are greater when you ice dive and take your rig to the surface when the temp is lower than 0c (32f). In this case it's guaranteed being frozen if there is some moisture inside. Some people just leave the rig in the water while making their SI.

Gotcha. The lowest temps I've dove in is about 34f, but I can see where the situation you describe could be problematic.

 

[elan]

thanks Cave Diver, I think I understand all your reasoning completely and find myself on the same page