1st or 2nd Stage Reg Failure on Stage/Deco Bottle

[DA Aquamaster]

I'm kind of surprised Doc Intrepid hasn't weighed in here. I remember him telling me a story about having one of his buddies turn on his deco gas and have the first stage explode on him -- He calmly turned the tank off and switched regs with one of his other bottles.

I would imagine it's not terribly good for the regulator, but it seems to me that one could live with a regulator that needs to be rebuilt better than living without a deco gas . . .

Bill told me the same story and as I heard it took a bit more time than I'd consider optimum and delayed the entire team at depth - with the result that Bill ended up on board with around 300 psi left for backgas. It made me seriously reconsider the whole swap the reg option as well as the regs I use for deco.

It is a good example though. The downside to a DIN reg is that if unpressurized they can screw themselves loose, flooding the reg. Most piston regs have no real issue with this (corrosion aside) while some diaphragm models can rupture the diaphragm. If you blow the reg on one of the deeper bottles, you can burn through a lot of time and gas swapping the reg off shore. In a cave, the conditions are a little more ammenable than they are trying to swap regs midwater on a deco line.

While swapping regs is an option if it is the last resort you have to access deco gas, I'd consider lost gas deco contingency plans long before I would swap a reg.

I have some SP regs in warranty still. One MK20/s600 (piston) and one Mk18/g250 (diaphram) Before their next due date I am going to flood them. Then leave them for a week or 2 and see if they still work "good enough"

The tech's gonna hate me

Well...probably not, but you may not be real happy with him. If he has any brains at all he will charge you extra labor for the additional time needed to clean them up. And most likely the cost of extra non-annual service parts will not be covered under warranty as the damage was do to flooding - an operator stupidity/abuse issue not a warranty issue.

A couple weeks ago I serviced a salt water flooded reg that was so far gone I did not recommend putting it back into service. Had I done it on my bench I'd have taken pictures to show you what happens when a reg is flooded with salt water and left to sit for a couple weeks. it is not pretty and what results is not a reg any self respecting technical diver will ever want to use again.

If you flood a reg, flush it out and then dissassemble, clean and dry it as soon as you possibly can. In most regs, flushing it with water and blowing air through it will not remove all of the salt or water from it as there are dead spaces in most regs where the salt will persist.

 

[PfcAJ]

If its just a little deco, I might just do it on BG or share my buddy's bottle. Longer deco means I'll switch the reg. Its up to you at the end of the day. How are you thermally? How much deco do you have to do. Is it a little free flow or a small free flow? Reg breathing wet? How wet? There are many variabled to this and there isn't an official "guideline." Its your dive, and if you're doing a dive where you might need to use this option, you should have had multiple instructor encounters to gather their opinion as well, as well as thinking about the options you have in water. All gear is team gear.

My BG regs aren't going to get touched at all. Those are real important.

 

[MonkSeal]

Before their next due date I am going to flood them.

I did this with DS4 - it was working some 30 min without any problem (then I surfaced). I serviced it same evening - no consequences at all.

 

[flareless]

During my Tec training last year we discussed the possibility of a team members deco reg failing. At the time it seemed like good info to have stored away but I didn't think the chances of something like that happening were very high. Hahaha, how naive!

On the last dive of my course I was paired up with my instructor. I had 2 deco bottles but he only had one. For the amount of deco required only one was necessary but I was to use 2 gasses, do the switches correctly, etc......

We had just come off a wonderful, long, deep drift dive. Deco was going well (although I have to admit fumbling around with the first gas switch). When we got to 30 feet I switched to my air for an air break. I expected my instructor to switch to his deco bottle but instead he pointed at his second stage and gave the signal for "this might not be working correctly".

Perplexed, I sort of just looked at him. Then he banged his deco second stage against the wall we were hanging next to and I got the picture. I positioned my first deco bottle (the one I was done with) so he could easily get to it. He removed his reg at the first stage point. He then took mine and installed it on his deco bottle. By the time it was time to come off my air break he was good to go. We did the rest of our decompression and ended the dive.

When we got back to his dive shop he gave me a brand new regulator setup (1st and 2nd stages, hoses, SPG) and thanked me for the use of my gear.

Now I just realized I'm in the DIR section of the Tech Diving forum. The training I did was DSAT (and it will likely get me killed, I know, I know......). DIR or not, however, I believe that underwater gear maintenance is something that everyone will have to deal with at some time. To that end I've been making sure that my second stages are not so tight that I can't swap them without a tool. I keep my hoses tight but not torqued down so much that replacement on the fly would be impossible. Finally, I'm adding a small, stainless steel adjustable wrench to my right pocket inventory (you don't have to be DIR to keep emergency gear in your right pocket - it just helps ). You never know when you may have to break down a set of doubles at depth

 

[DA Aquamaster]

If its just a little deco, I might just do it on BG or share my buddy's bottle. Longer deco means I'll switch the reg. Its up to you at the end of the day. How are you thermally? How much deco do you have to do. Is it a little free flow or a small free flow? Reg breathing wet? How wet? There are many variabled to this and there isn't an official "guideline." Its your dive, and if you're doing a dive where you might need to use this option, you should have had multiple instructor encounters to gather their opinion as well, as well as thinking about the options you have in water. All gear is team gear.

That's reasonable. I tend to look at it in terms of the big picture. If the dive gets deep enough or the deco long enough that doing the deco on back gas (the single deco gas lost gas contingency) is going to take an excessive amount of time or push the 1/3rd reserve to the limit, its time to take a second deco gas. Then doing the contingency on back gas and one deco gas or the other becomes a much more attractive contingency with less time penalty.

When contemplating a reg swap, when the failure occurs is important. Obviously if it happens on the second bottle, there is little additional risk, as with proper lost gas planning the back gas is by definition adequate to get you to the surface if you still can't access the second gas if the reg fails after the swap.

The concern with switching regs in order to access the first deco gas in a two deco gas situation would be that you would be taking the only remaining functional deco reg off, flooding it and then betting all your deco gas on it working properly when pressurized on the other bottle. If it does not, you either need enough back gas to get you to the surface on the much longer back gas only schedule or you need to go borrowing gas from another team member. Even if it works on the first deco bottle, you are still at risk of it failing when you switch it to the second deco gas. And depending on the time taken at depth to make the first switch, you may not have the reserve you planned to have and your ability to complete the deco on back gas may be compromised if the reg fails after the switch to the second deco bottle. It all adds to the risk/benefits that have to be considered.

Personally I use piston regs to reduce the failure potential of pressurizing a flooded reg/. And I am just not inclined to consider a reg swap to access the first deco gas - my preferred response would be to do the slightly longer contingency on back gas and the second deco gas. Swapping a reg is pretty far down the list of options.

 

[rjack321]

Well...probably not, but you may not be real happy with him. If he has any brains at all he will charge you extra labor for the additional time needed to clean them up. And most likely the cost of extra non-annual service parts will not be covered under warranty as the damage was do to flooding - an operator stupidity/abuse issue not a warranty issue.

A couple weeks ago I serviced a salt water flooded reg that was so far gone I did not recommend putting it back into service. Had I done it on my bench I'd have taken pictures to show you what happens when a reg is flooded with salt water and left to sit for a couple weeks. it is not pretty and what results is not a reg any self respecting technical diver will ever want to use again.

If you flood a reg, flush it out and then dissassemble, clean and dry it as soon as you possibly can. In most regs, flushing it with water and blowing air through it will not remove all of the salt or water from it as there are dead spaces in most regs where the salt will persist.

They just came back from service and this is the 2nd time "non-annual" parts have been replaced under warranty. Last year it was cracked inlet tubes, this year it was a warped 2nd stage body. I don't know what I'm doing but as one of the largest authorized SP dealers around they seem fine replacing stuff on 8yo in warranty regs.

 

[rjack321]

That's reasonable. I tend to look at it in terms of the big picture. If the dive gets deep enough or the deco long enough that doing the deco on back gas (the single deco gas lost gas contingency) is going to take an excessive amount of time or push the 1/3rd reserve to the limit, its time to take a second deco gas. Then doing the contingency on back gas and one deco gas or the other becomes a much more attractive contingency with less time penalty.

When contemplating a reg swap, when the failure occurs is important. Obviously if it happens on the second bottle, there is little additional risk, as with proper lost gas planning the back gas is by definition adequate to get you to the surface if you still can't access the second gas if the reg fails after the swap.

The concern with switching regs in order to access the first deco gas in a two deco gas situation would be that you would be taking the only remaining functional deco reg off, flooding it and then betting all your deco gas on it working properly when pressurized on the other bottle. If it does not, you either need enough back gas to get you to the surface on the much longer back gas only schedule or you need to go borrowing gas from another team member. Even if it works on the first deco bottle, you are still at risk of it failing when you switch it to the second deco gas. And depending on the time taken at depth to make the first switch, you may not have the reserve you planned to have and your ability to complete the deco on back gas may be compromised if the reg fails after the switch to the second deco bottle. It all adds to the risk/benefits that have to be considered.

Personally I use piston regs to reduce the failure potential of pressurizing a flooded reg/. And I am just not inclined to consider a reg swap to access the first deco gas - my preferred response would be to do the slightly longer contingency on back gas and the second deco gas. Swapping a reg is pretty far down the list of options.

I would not swap an O2 reg onto my 50% bottle. (nor either onto a 35/25 bottle or stage (duh!)). If you share the 50% for the full time each you will run it out but look at how the maths works out...

e.g. 20 mins of 50% deco to do:
70- 6mins on, 6mins of backgas while you buddy does his = 9mins deco done
60- 6mins on, 6mins on backgas = 9 mins deco done
50- 2 on, 2 off = 3mins done
50% bottle runs out about here and you have already done the equivalent of 21 mins of 50% deco already. So you can continue your normal schedule up to the 20ft switch. If this is a one gas dive I would pad the shallow stops by about 25-50%.

 

[adelman]

true story. this guy has a wrench in his pocket at all times lol

Ok, I'll bite. What is a DIR-approved wrench? Nears as I can figure, you need two of these with SS boltsnaps tied on...

stainless steel 7" adjustable wrench. Steritools

I think the 10227 model would have better buoyancy characteristics, not to mention the bottle opener.

 

[b1gcountry]

6" adjustable wrench from Harbor Freight.
Harbor Freight Tools - Quality Tools at the Lowest Prices
about $3

of course I mostly dive in freshwater.

Tom

 

[ianr33]

The concern with switching regs in order to access the first deco gas in a two deco gas situation would be that you would be taking the only remaining functional deco reg off, flooding it and then betting all your deco gas on it working properly when pressurized on the other bottle.

If push really comes to shove why not just use a backgas reg? Might be hard taking it off yourself when diving backmount but a buddy could do it for you.

Obviously would have to be a pretty dire situation to do this,lots of preferred options e.g deco on backgas, buddy breathe deco gas, buddy hands off first deco bottle at some point etc.