Rebreather World - View Single Post - Offboard connection setup

womble · 31st October 2007, 10:51

Quote: (Originally Posted by Simon A)

Womble,
It seems like you are adding a load of extra joints and making it over complicated.
You say you are using a BOV and offboard O2/Dil?
If so, I would consider something along the lines of:-
Onboard O2 plumbed into solenoid
Offboard O2 plumbed into O2 manual add.
Onboard Dil plumbed into ADV
Offboard Dil (bailout) plumbed into BOV

That gives you access to all your gases, the onboard O2 cylinder valve can be used to isolate the solenoid, the onboard Dil cylinder valve can be used to isolate the ADV and you have access to your bailout through the BOV without any restrictions that could give higher WOB at depth (high WOB is bad when trying to recover from a CO2 hit)

HTH
Simon A

simon, this is what I have at the moment, and it is pretty foolproof. If I dont go for the setup mentioned this is what i'll do. No halfway house. The downside to this is
1) you cannot isolate the solenoid and still use onboard O2 to fly manually
2) Only one gas is available thro the BOV (unless you use QDs - which I dont on my BOV)

Quote: (Originally Posted by Ivon)

Hey Pete,
This is the same set up as I use but without the BOV, just into the CL, it works for me.

Hope your good, you down at Chepstow next weekend?

Ivon.

Hello mate, I'm gonna be there sat or sunday, maybe also monday/tue/weds as I had a trip to st abbs blown out and nothing better to do!! send me a pm if you want to meet up.

Quote: (Originally Posted by Brad_Horn)

Womble,

Curious as to why you specifically want to:
"1) use a redundant o2 source
2) isolate the solenoid
3) allow access to onboard and offboard diluents through the ADV
4) allow access to onboard and offboard gasses throught the BOV"

What is your failure analysis for needing redundant O2 physically bolted to the rig, wouldn't an O2 stage suffice with whip for manual inflator?

Could you add a standard 2nd stage shutoff close to your 1st stage for the solenoid feed lp hose, allowing open/close solenoid option, without disconnecting any hoses. Similar to what I understand the boris has for dil/o2 cutoff.

Do you need the ADV to have dual feed, wouldn't it be less complex to just alternate to manual inflation if the ADV or its feed fail?

Use of a gas switch block allows access to on/off-board gas, but how do you confirm what gas you are breathing under stress? In particular I am thinking of when a hypoxic dil is in the onboard gas you have to go emergency oc through the bov on the surface and lights out... or alternatively, you accidentally leave the gas block switched to a hot mix from a stage through decent, need a couple of sanity breaths due to high workload on the bottom and ox-tox....

Just my 2 cents

regards
brad

Brad,

I dont use 100%O2 as a bailout, as it can only be used at 6m. if you run some plans on V planner you will find that you will need Sh*tloads of deep bailout to get you to 6m, and it will give you a longer in water time than 50ish % which is what I use. Just what I have been thought and what works for me. Hence the small redundant O2 bottle.

RE: your other 2 points, dual ADV feed would be nice, but not essential, and yes, task loading could lead to accidents. . . . Dilemma

31st October 2007, 10:51	#7 (permalink)
womble Custom Title Allowed! Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Aug 2006 Location: UK Posts: 188	Re: Offboard connection setup - Thoughts please? Quote: (Originally Posted by Simon A) Womble, It seems like you are adding a load of extra joints and making it over complicated. You say you are using a BOV and offboard O2/Dil? If so, I would consider something along the lines of:- Onboard O2 plumbed into solenoid Offboard O2 plumbed into O2 manual add. Onboard Dil plumbed into ADV Offboard Dil (bailout) plumbed into BOV That gives you access to all your gases, the onboard O2 cylinder valve can be used to isolate the solenoid, the onboard Dil cylinder valve can be used to isolate the ADV and you have access to your bailout through the BOV without any restrictions that could give higher WOB at depth (high WOB is bad when trying to recover from a CO2 hit) HTH Simon A simon, this is what I have at the moment, and it is pretty foolproof. If I dont go for the setup mentioned this is what i'll do. No halfway house. The downside to this is 1) you cannot isolate the solenoid and still use onboard O2 to fly manually 2) Only one gas is available thro the BOV (unless you use QDs - which I dont on my BOV) Quote: (Originally Posted by Ivon) Hey Pete, This is the same set up as I use but without the BOV, just into the CL, it works for me. Hope your good, you down at Chepstow next weekend? Ivon. Hello mate, I'm gonna be there sat or sunday, maybe also monday/tue/weds as I had a trip to st abbs blown out and nothing better to do!! send me a pm if you want to meet up. Quote: (Originally Posted by Brad_Horn) Womble, Curious as to why you specifically want to: "1) use a redundant o2 source 2) isolate the solenoid 3) allow access to onboard and offboard diluents through the ADV 4) allow access to onboard and offboard gasses throught the BOV" What is your failure analysis for needing redundant O2 physically bolted to the rig, wouldn't an O2 stage suffice with whip for manual inflator? Could you add a standard 2nd stage shutoff close to your 1st stage for the solenoid feed lp hose, allowing open/close solenoid option, without disconnecting any hoses. Similar to what I understand the boris has for dil/o2 cutoff. Do you need the ADV to have dual feed, wouldn't it be less complex to just alternate to manual inflation if the ADV or its feed fail? Use of a gas switch block allows access to on/off-board gas, but how do you confirm what gas you are breathing under stress? In particular I am thinking of when a hypoxic dil is in the onboard gas you have to go emergency oc through the bov on the surface and lights out... or alternatively, you accidentally leave the gas block switched to a hot mix from a stage through decent, need a couple of sanity breaths due to high workload on the bottom and ox-tox.... Just my 2 cents regards brad Brad, I dont use 100%O2 as a bailout, as it can only be used at 6m. if you run some plans on V planner you will find that you will need Sh*tloads of deep bailout to get you to 6m, and it will give you a longer in water time than 50ish % which is what I use. Just what I have been thought and what works for me. Hence the small redundant O2 bottle. RE: your other 2 points, dual ADV feed would be nice, but not essential, and yes, task loading could lead to accidents. . . . Dilemma __________________ "What could possibly go wrong?? . . "
(Offline)