Routing for Helium misers

[Abbo]

At the moment I use air dil on shallower dives down to 50m, but I want to start using 17/30 instead - because I can. Over a weekend diving I typically need the diluent topping up, and I couldn't get it filled in the field with trimix. What I therefore want to do is put air in the bail-out tank and 17/30 in the on-board. Then I could use air from the bail-out to run the wings. Does anyone do this? Does it make any sense, or am I merely adding extra risk? HOW DO YOU DO THE ROUTING TO MAKE SURE THE GASES ARE KEPT SEPERATE?

At the moment, I have a pretty common set-up: I have a hose going from my on-board diluent gas to a manifold; 3 hoses come off the manifold to the 'breather, the BOV and the wings. I have connected a hose from my bail-out gas, via a quick disconnect, to the manifold.

[JS1scuba]

At the moment I use air dil on shallower dives down to 50m, but I want to start using 17/30 instead - because I can. Over a weekend diving I typically need the diluent topping up, and I couldn't get it filled in the field with trimix. What I therefore want to do is put air in the bail-out tank and 17/30 in the on-board. Then I could use air from the bail-out to run the wings. Does anyone do this? Does it make any sense, or am I merely adding extra risk? HOW DO YOU DO THE ROUTING TO MAKE SURE THE GASES ARE KEPT SEPERATE?

At the moment, I have a pretty common set-up: I have a hose going from my on-board diluent gas to a manifold; 3 hoses come off the manifold to the 'breather, the BOV and the wings. I have connected a hose from my bail-out gas, via a quick disconnect, to the manifold.

I drive my dry-suit off my off-board bail out. You can do your wing as well though it becomes convoluted should you need to drop the off-board bottle.

What you might want to consider doing is getting some additonal bottles for your unit with Dil in them OR put your 17/30 in larger tank and transfil to your smaller bottles as needed.

Cheers

[diverreb]

A lot of us use a separate 6 CF bottle for Wing or Dry Suit inflation...

There are lots of places to attach the bottle. There are small inexpensive first stages and all you need is an OP button valve, single inflator hose, and a small button pressure gauge. Works very well....

Then keep an inflator hose on your Bail Out, if for some reason you loose or run out of gas in the small bottle, you won't be screwed.

Richie

[HaisaiMatt]

I see two approaches, one is to use a dedicated bottle for drysuit and wing inflation, and the other is to use the bailout bottle. I try to do at least one dive each week deeper than 200 feet, and I have always used my offboard bailout for my drysuit. In my opinion, adding another bottle is not necessary, adds unneeded failure points, and is one more thing to get snagged in a wreck, line, or kelp.

Another consideration you may want to take into account is the head spin you may get if you switched to air from mix at 50 meters. Just remember if you're bailing out, you will be task saturated and are going to want to be able to think clearly. I find it worse switching from a shallower EAD to a deeper one than had I just been on the leaner gas the entire dive.

Of course only you know how you will react, and I am sure you can make the right choices for yourself, I just wanted to give you some input from my experiences.

Richie has the BOV hose routing setup down to a science, and he was kind enough to email me pictures which I think may be posted on the site.

Matt

[Mark Chase]

I run 3ltr tins on the inspo and KISS and I use typically 50-80 bar of diluent on a dive giving me two dives on a 230bar fill.

I run suit inflate off a 1.5ltr bottle which doubles as gas for lift bags. I have a redundant suit/ wing hose on my bailout for the problem days but i don't use it. Its a pain if you keep nicking the tops off your bailout for wing or suit inflate. Sooner or later you end up jumping in with less than optimal bailout gas.

If I wanted to save mix Id run the wing off the 1.5ltr suit bottle and my suit off the bailout. Seeing as I use wing for buoyancy it eats the most gas. I have toyed with running the wing of the 1.5 and using the little 0.8 tanks I have for running the suit but with 3ltrs of 18/45 costing me about £5 I cant really be bothered.


What ever you do just don't run all your buoyancy off a single gas source.


ATB

Mark

[Mike]

Run your wing on O2. It's cheaper than mix, and if you use an air 2 it gives you OC access to O2

Mike