Topping Off Bailouts

[JonG1]

assuming you aren't offboarding dil, just wondering how people approach the point when a bailout or OC deco gas bottle gets to the point where a top up is required. You alaways lose a bit either just through pressurisatioin or de-pressuriation, testing a BOV etc.

It's an expensive option to blow it down and start again, I could practice bailout with the gas I guess, but I tend to do that on my air sidemounts.

Does anyone have a rule of thumb as to how far from a standard gas they are happy to stray. My LDS doesn't bank standard gas everything is mixed from constituent gases.

 

[ahereng]

Booster and banked gasses. So when the pressure gets down to 190bar I top off again, or before dives where full pressure is a point.

 

[Wibble]

I’ll top off with air to get the pressure back up and if the oxygen or helium gets a bit high/low then will do a rich (10/75) top off to bring it back into my tolerance, with an air top for pressure.

Personally -- within reason -- am far more concerned about the gas volume than the mix; other people may be different.

 

[Jack Hammer]

I just keep a set of hp130s full of trimix and use my booster to top off the bailout from that.

 

[rjack321]

I boost from banked gas. But my BOs go out of hydro before I really need to top them up lol

Usually if I end up with a partial fill somehow, I will take all that gas and put it into my trimix bank, hydro and vip the tank. Then remix using the bank as a starting point depending on what I want.

 

[macado]

I boost a bit beyond fill pressure to account for random purges, testing, etc. I try to keep my AL80 stages at 3200-3250psi (~225bar). It's not much but it does help. It's entirely arbitrary but I don't generally top off until things start getting lower than 2700psi (~185 bar).

I know it doesn't help your answer as I use standard gases and have a booster and compressor to fix my mixes but I'm generally more concerned with helium content/END than I am for O2 for my deeper mixes. My 15/55 for example, if it's at 2700-2800psi i'd be fine topping it off with air to 3100psi to get ~15.5-16 / 48-50ish. I'll eventually just top it off with more Helium to fix it.

 

[Tug]

I’m in the “be friends with people who have boosters” camp. Although with the amount of beer I bring them it might be time to get a booster myself

In all seriously, I do the same as @macado. I have enough trimix banks for my rebreather bottles that I can throw a bailout on there for the last couple hundred psi. What causes issues is when I’m traveling an have a bailout drain accidentally and realize it’s about 3 years out of hydro… whoops

 

[broncobowsher]

Own a booster. Top off before hydro expires. Don't even have a vis sticker on it.

 

[Dave Whitlow]

assuming you aren't offboarding dil, just wondering how people approach the point when a bailout or OC deco gas bottle gets to the point where a top up is required. You alaways lose a bit either just through pressurisatioin or de-pressuriation, testing a BOV etc.

It's an expensive option to blow it down and start again, I could practice bailout with the gas I guess, but I tend to do that on my air sidemounts.

Does anyone have a rule of thumb as to how far from a standard gas they are happy to stray. My LDS doesn't bank standard gas everything is mixed from constituent gases.

I have banked 15/55, O2, and helium, 32%, and a booster, so I keep the bailouts topped up with something approaching the original mix. Sometimes a bit of fiddling is needed but I'm not overly fussed about standard mixes, only mixes I've analysed and labelled. That said, I keep them similar to standard mixes (+/- 2% on O2 and +/- 5% on He) in case it actually matters.

 

[Tracy]

I use AL80s for bailout and I also use it for offboard Diluent.
My personal rotation is simple and works for me.
I have them filled with 18/45. When I get down to 2800 psi, I top it to 3100 with Helium and dive 16/50.
When it gets to 2800, I top it to 3100 with 32% and dive 18/45.
When it gets to 2800, I top it to 3100 with Helium and dive 16/50.
This pattern continues indefinitely. Both of those gases are adequate for my normal dives and it is a simple rotation.