Two Tank Questions

[Scuba_Dooba_NJ]

Two tank questions. Why do people use Argon for drsysuit inflation and why is it necessary to perhaps turn air while diving?

Thanks,

John

 

[pants!]

The big benefit from using argon is when using trimix as back gas. Trimix has helium, which is a great conductor of heat, so it makes you lose heat faster. Argon may be a bit better at insulating than air or nitrox.. some people claim it's better, some people say it's garbage. Either way it's better than helium. I've seen people use argon bottles just filled with air when diving trimix, so whatever.

I'm not sure what your second question means.

 

[abitton]

Argon is a better insulator than air, that's why you even have windows that have argon between panes of glass to improve energy efficiency.

I'm not too clear about the 2nd part of your question, tho...

Alex

 

[SDAnderson]

Argon is a much better insulator than helium mixes, so it keeps trimix divers warmer. There isn't as much of a benefit for nitrox/air divers, but once you've got the bottle...

Many divers want a separate inflation bottle for their suit because, (a) they don't want to be "wasting" backgas on their suit inflation, and; (b) it's easier/safer to deal with a runaway inflation problem that way.

 

[The Kraken]

I think your question about "turning air" refers to using different mixes at different depths.

If I am correct, it has to do with the partial pressure of oxygen and nitrogen in the technical diving environment.

Below about 218' normal air can be deadly so technical divers reduce the amount of O2 in their breathing gas to reduce the PPO2 level to prevent oxygen toxicity. Tech divers will also reduce the amount of nitrogen in their mixes to prevent nitrogen narcosis at greather depths.

For their decompression stops, tech divers often times use a breathing gas with an extremely high percentage of oxygen to reduce the decompression stop time, or in another way of saying it, speed up the off gassing process.

I hope this answers your question; if not there are some really great divers on the board here that can address your question to your heart's desire.

the K

 

[jamiep3]

I took the "turning air", to mean turn off. If that is the case, it is to isolate a malfunctioning regulator, or in case of a failure in part of the manifold.

 

[cool_hardware52]

I'm guessing here too about the second question, but my interpretation was "turning off the air" i.e. why would one want to reach the valves and cycle them.

When single tank diving it's a great skill to have in case you jump in and your valve is off.

When diving doubles (or H-Valves) is allows one to deal with certain failures or problems like regulator freeflows etc.

Hope this helps. If not fire away, lots of folks here to help.


Tobin

 

[Diver0001]

Argon is a much better insulator than helium mixes, so it keeps trimix divers warmer. There isn't as much of a benefit for nitrox/air divers, but once you've got the bottle...

Many divers want a separate inflation bottle for their suit because, (a) they don't want to be "wasting" backgas on their suit inflation, and; (b) it's easier/safer to deal with a runaway inflation problem that way.

I don't see how having an argon bottle makes it easier to deal with run-away inflation problems. Inless I'm missing something I'd say that dealing with run-away inflation is about diver skill, not gear.... care to elaborate?
R..

 

[SDAnderson]

I don't see how having an argon bottle makes it easier to deal with run-away inflation problems. Inless I'm missing something I'd say that dealing with run-away inflation is about diver skill, not gear.... care to elaborate?
R..

I dive with a 6cf inflation bottle on my waist, which gives me several advantages over a larger bottle backmounted or back gas in the event of a free-flowing regulator or valve:

• I can easily shut down the inflation tank valve and won't be interfering with a breathing regulator.
• I don't have to worry about loss of back gas should there be an inflation problem, especially should I need to cut the inflation hose in an emergency.
• Because there is a very limited supply of gas, the danger of adding a runaway ascent to the task list is reduced and quickly self-eliminated.

Deep diving in cold water sometimes makes for paranoid diving. :14:

 

[Diver0001]

I dive with a 6cf inflation bottle on my waist, which gives me several advantages over a larger bottle backmounted or back gas in the event of a free-flowing regulator or valve:

• I can easily shut down the inflation tank valve and won't be interfering with a breathing regulator.
• I don't have to worry about loss of back gas should there be an inflation problem, especially should I need to cut the inflation hose in an emergency.
• Because there is a very limited supply of gas, the danger of adding a runaway ascent to the task list is reduced and quickly self-eliminated.

Deep diving in cold water sometimes makes for paranoid diving. :14:

Aaaahhh.... I see where you're coming from. We were thinking about the run-away from two different angles. I was assuming run-away inflator and you were thinking run-away 1st stage.

Thanks for the clarification.

R..