Gas Connection system.

Tim Franks

I would like some advice about the AP gas connection system. I have some ideas about what I would like to do with it but at the moment lack the knowledge of what is possible.

I have an Inspiration fitted with a Golem BOV. The gas hose to the BOV is taken from the diluant manifold. So if I need to go to OC it’s just a twist of the knob and I’m breathing from the 3ltr onboard cylinder. What I want to be able to do is run the male side of AP’s GCS to the same diluant manifold and have the female side of the hose connected to an off board 7ltr side slung stage. Therefore once on O/C I have sufficient gas for a complete bailout without taking the BOV out of my mouth. Does anyone already use this configuration?

Can the system be taken a step further so that a second off board stage with a richer mix is incorporated using the female side of the GCS hose from its first stage. Does this make it possible to gas switch to the deco mix via the BOV?

How easy is the actual gas switch?

How easy is it to disconnect and reconnect the GCS hoses underwater?

What do you do at the switch – swap back to breathe the onboard dil whilst swapping hoses?

I know if I don’t mention it someone else will, and I assume I won’t win whatever I say, as an added safeguard I would still keep normal OC second stages on the off board supply.

I would certainly appreciate anyone’s experience of a similar system are there pitfalls?

Many thanks.

tiggerbiker

i run this system - almost.i plumbed in an ali80 to my dil manifold via the GCS and connected my BOV directly to the manifold.it is possible to disconnect the coupling underwater but reconnection is neigh on impossible unless the lines are drained.hence i use an ali80 filled with my dil gas on the left side and if i'm doing a serious deco dive, i'll also carry a rich deco mix on the right but the cylinder just has bailout regs on it, it doesnt have a GCS on it.

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Tim Franks

Thanks mate that's a help. The offboard cylinder - do you run it turned on or off? With or without OC second stage? What sequence of turning valves on and off do you go through to get access to the offboard gas. Presumably the onboard dil is finally turned off.

Thanks again.

Tim.

tiggerbiker

i actually run with all taps on,
my thinking is that if i have to bail out, i'll be stressed and possibly wont remember to turn on the bailout tank.

at the end of a dive at stoney cove i decided to do lots of practice drills and deliberatly drained the on-board 3ltr dil tank by breathing off my BOV - i watched the spg slowly go to zero but the gas still kept coming to me - then i realized that it was coming through from the offboard tank via the GCS!

i also have my old jetstream reg on the bailout tank - if my buddy gets into trouble they get that reg (if needed, i can disconnect the tank from my side and just hand it to them)

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the more i learn, the more i realize i know nothing