[CCR900]

Bit of a strange one that maybe someone can help me out with.

I was running a bit low on on-board diluent so decided to run the dive from a side mount. Off-board came through the gas block/standard swagelock fitting from CCRB.

I dropped into water with the on-board dil open & isloation valve open, also off-board dil (same gas) plugged in and on. No complaints on surface nor on the descent but suddenly at about 47m I hear a nasty noise (some where between an alarm going off and a scream (leaking gas through a small orifice right?)). Buddy signals I have gas comining out of my back (not an out and out free flow but a constant flow of gas). Nothing wrong on my display, isolated on board gas but screaming continues so shut off external tank, screaming stops as does leak.

At 6mm I turned it back on and nothing, at the surface it was the same thing, no leaks.

Please note, when there is no plug in there are no leaks.

F

[hypoxicexplorer]

Are you saying your off board is causing your adv to free flow? If that is the case I would check the IP of the off board 1st stage.

[Frankie Pellegrino]

I’m not sure If I fully understand where the leak ever came from.


But here’s a guess

If you turned your off board tank off and that stopped the leak. It sounds like you had a High Pressure creep on that first stage. That slow creep caused the Over Pressure value on your on broads first stage to release and free flow ( The Dill gas is all piped together). The nasty noise you heard was the Dill first releasing ( Then a stead flow). I don't think there are any one way check valves in the Boris piping. I also think the Over pressure valve releases at about 225PSI.
Please keep us posted on your findings.

[CCR900]

Hypoex (sorry don't know your name) - ADV didn't kick in (noise was wrong) no loss of bouyancy, no change in WOB. Never say never so I will keep looking at that one.

Frankie - Interesting. I didn't have any reflective plate to take a look so i'm relying on other diver's comments. He said the gas was escaping from the box but I wasn't in the mood to ask him to take the cover off him being my student an' all .

Will check the the IP (where is my fu*king IP gauge) on the side mount 1st. In my defence the 2nd stage hasn't been leaking (no OP on that 1st stage - Apex).

I have recently stripped the boris down to its bare bones as the electronics were sent to UK for upgrade and I serviced the 1st stage. But the gas block wasn't messed with, nor were the pipes. Boris works fine on it own.

Why would depth trigger such an event (if depth was a factor, that is) or was it that the 2ltr tank's pressure dropped below the external tank's?

Rgds

Fil

[Frankie Pellegrino]

Quote: (Originally Posted by CCR900)

Hypoex (sorry don't know your name) - ADV didn't kick in (noise was wrong) no loss of bouyancy, no change in WOB. Never say never so I will keep looking at that one.

Frankie - Interesting. I didn't have any reflective plate to take a look so i'm relying on other diver's comments. He said the gas was escaping from the box but I wasn't in the mood to ask him to take the cover off him being my student an' all .

Will check the the IP (where is my fu*king IP gauge) on the side mount 1st. In my defence the 2nd stage hasn't been leaking (no OP on that 1st stage - Apex).

I have recently stripped the boris down to its bare bones as the electronics were sent to UK for upgrade and I serviced the 1st stage. But the gas block wasn't messed with, nor were the pipes. Boris works fine on it own.

Why would depth trigger such an event (if depth was a factor, that is) or was it that the 2ltr tank's pressure dropped below the external tank's?

Rgds

Fil

Hey Fil
Those are all good questions.

I really have no clue why depth could have an effect on the mysterious free flow……
May be the ambient water pressure on the first stage caused the IP to creep up high enough to set off the Over pressure valve. Or your on board tank was almost empty..... and that effected it????

(Just for your info) The over pressure valves that CCR installs on Boris’s first stages are adjustable. Just use a allen key at the end and tighten down a little.

May be the internal spring got weak and it released .

If you do tighten it down I would put a IP gauge on the low pressure line and make sure in free flows at about 225psi.
Good luck ..& keep me posted.

[DrJM]

Hey Fil

I had the same story at -45m 500m from exit, APART from the fact that the OPV of the first stage of the inboard tank became stuck open, I lost in 1/2 minute all the inboard gas and then I lost 100b of a 20 lit of my off board tank over 290 min ...
since I removed the OPV



Jerome

[Drmike]

Quote: (Originally Posted by CCR900)

Bit of a strange one that maybe someone can help me out with.

I was running a bit low on on-board diluent so decided to run the dive from a side mount. Off-board came through the gas block/standard swagelock fitting from CCRB.

I dropped into water with the on-board dil open & isloation valve open, also off-board dil (same gas) plugged in and on. No complaints on surface nor on the descent but suddenly at about 47m I hear a nasty noise (some where between an alarm going off and a scream (leaking gas through a small orifice right?)). Buddy signals I have gas comining out of my back (not an out and out free flow but a constant flow of gas). Nothing wrong on my display, isolated on board gas but screaming continues so shut off external tank, screaming stops as does leak.

At 6mm I turned it back on and nothing, at the surface it was the same thing, no leaks.

Please note, when there is no plug in there are no leaks.

F

had the same thing happen to me - its likely your boris dil 1st stage opv


you may want to check your IP on your offboard or service the opv.

added: opps DrJ beat me to it

[Frankie Pellegrino]

Quote: (Originally Posted by DrJM)

Hey Fil

I had the same story at -45m 500m from exit, APART from the fact that the OPV of the first stage of the inboard tank became stuck open, I lost in 1/2 minute all the inboard gas and then I lost 100b of a 20 lit of my off board tank over 290 min ...
since I removed the OPV



Jerome

Hey Jerome

Removing this OPV from your dill first stage is very Dangerous

These are the con's in my opinion.

1) we know the 1/8 inch piping can handle the IP creep...(I believe 5,000 to 10,000 PSI ..but I'm not 100% sure)...
Question...... will you be able to press the manual dill button to put gas in the loop if you have a serious IP creep?

2) Since the Boris ADV is a upstream design.... and your first stage IP creeps up.... And you don't have a Dill first stage OPV....the Valve insert (Blue rubber thing) will mush through its holder and make the whole dill side of your kit inoperable. The valve insert will push through the holder and look like blue spaghetti pushed through a die. (I've seen this before on a Poseidon regulator)

3)NO ADV.... and NO manual Dill add..... That's bad!

4)Since Boris’s ADV is the guts of a Poseidon’s second stage. You need a OPV installed on that first stage. If you think about it ... Poseidon's (jet stream and extreme regulators) have that spring loaded OPV at the end of their hoses. YOU NEED A OPV on that Dill first stage

My advice is install a new OPV valve on that first stage .Or service the one you have. Your rolling the dice with that modification. I know you do some real deep bad ass dives.....
I want you around to tell every body about them
Best of luck Frankie

[DrJM]

Hey Frankie

thanks for reassuring me

I see your points and appreciate them, but I don't mind losing the 2 lit on board gas BUT losing a lot of offboard gas really anoy me(mainly if deep yoyo profile), so maybe a possible solution will be to install a one way valve on the exit pipe of the inboard 1st stage dil, so like that even if the opv is stuck open I'll not loose my offboard dil gas ... food for thought

Jerome

[Frankie Pellegrino]

Hey Jerome

Excellent idea!! It’s great food for thought.
That’s why I love this forum.
We can always learn something new. And when you here a different opinion it makes you think…..
There is no doubt in my mind that you have the skill and ability to handle any and all situations. After all ….you’re one of the badest of the bad ….in the deep diving community.

I can remember when I first became a rebreather diver .
My instructor (Andrew Driver) Which I feel is a shit hot rebreather guy.
Told me ….you’re now a thinking diver …..You have to know how to recognize situations /Problems and correct them…. or know when to bail out.

After reading your post I might make that modification.
It sounds like a smart educated mod. I’m going to think about the pros and cons
If it happen to a few people… it could happen to me! If we can rectify a possible in water failure ..it makes good sense to rectify it before it happens.

Have some Green from Lefronc!!!

Great info…Cheers