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Re: Argonaut DSV

Posted: Sat Oct 06, 2018 1:08 pm
by luis
lexvil wrote:
Sat Oct 06, 2018 8:20 am
It’s not the hose, it happens regardless of the hoses used. I tried changing the valve and I can say it seemed to help for a while but since the issue is intermittent and it reoccurred I can’t say that’s it. I had assumed it to be perhaps something unique to cold water because Bryan could never find the issue in his testing, it never gets past the valves in the DSV and breaths are always dry. It may have something to do with posisition, maybe I’ll take it out soon and try some different positions while listening for the glug, this is disconcerting to the level that I didn’t take the Kraken to Truk.
I haven't had an issue with cold water in Maine, even ice diving.

As I replied to you in ScubaBoard, the issue could be a somewhat loose valve, not held tightly by the arrow head in the valve stem. This could happen if the tolerances are off. This could possibly give you an intermittent leak.

A loose valve can be resolved easily by putting a little drop of silicone seal under the arrow head in the stem of the valve and make sure to pull the valve stem to fully seat the valve.

I am not going to repeat what I posted in ScubaBoard, so here is a link to that thread:
https://www.scubaboard.com/community/th ... ue.568639/


That is a real bummer that you didn't take your Kraken to Truk. Five of us went to Truk last February. We were all diving Krakens. I did 36 dives in Truk (and 2 in Guam) with my primary Argonaut and it was great. The dive master and the Captain of the Odyssey borrowed my spare Kraken.
Heck, I passed a kidney stone while I was in Truk and that didn't stopped me from diving.

Re: Argonaut DSV

Posted: Sat Oct 06, 2018 1:29 pm
by DerekRalston
Replace the O-rings in your DSV. Worked wonders for me. My DSV was new and leaked like a sieve on the first dive. Bryan suggested changing the O-rings and it's dry as a bone now.

Re: Argonaut DSV

Posted: Sat Oct 06, 2018 2:24 pm
by lexvil
I just installed a G250 exhaust valve, it feels a touch less stiff and holds a very slight vacuum better than the one that was in it. All I need now is some decent conditions to give it a try.

Re: Argonaut DSV

Posted: Sat Oct 06, 2018 4:58 pm
by Fibonacci
While a loose fit between the exhaust stem and moulded in hole in the DBE/Kraken body may well lead to some degree of wet breathing (same as ill-fitting o-rings in the DSV or loose hose clamps) the issue I experienced is a FULL flood of the exhaust loop on a regular but intermittent basis like lexvil and tbone1004.

Takes about 5-10 seconds and you can clearly hear large volumes of water glugging in and WOB becomes extremely difficult... certainly disconcerting, a feeling of choking UW :shock:

It's not dependent on water temperature... all my floods occurred in tropical PNG waters with an average temperature of 29C!

I had to stop diving the Kraken by Day 3 of my LOB trip... the niggling hose loop flooding issue compounded by a failure of the HP seat!
Luckily I had also brought my old bullet proof Conshelf XIV and Sea Hornet Command Air backup reg set. So my near-new AU$900 Kraken DH sat in my bag for the rest of the 9 day trip while my $75 garage sale special soldiered on reliably :(

I think the root cause is indeed case geometry, hose volume and exhaust valve stiffness... with paused breathing at a certain body position the exhaust valve lifts up and the hose floods rapidly.
I would happily sacrifice some exhaust WOB for more reliability!
Adding tapered triangular stiffening ribs to the upper surface of the can exhaust valve would allow cracking efforts to be tuned to better match the Kraken's characteristics.

We are just coming out of Winter here so sea temps are still around 14C and not much fun to be in for extended experimentation... be interested in lexvil's trials with the G250 exhaust valve.

Yet another issue is the new 90 Duro o-rings locking the DSV after a few days sitting... works fine on the bench after reassembly.
But despite being new, and freshly lubricated they bond themselves to the inside of the outer housing after a few days sitting in my dive bag and the whole DSV assembly is locked up in whatever position you last left it in. Tried Dow 111 and Teflon loaded silicon lubes, no difference.
I am going to trial some Teflon o-rings and see if that improves things... -028 for the inner barrel and mouthpiece port, -027 for the wagon wheels.

Re: Argonaut DSV

Posted: Sun Apr 28, 2019 12:58 pm
by ScubaLawyer
Took my Phoenix w/DSV out for a spin this morning to test my new GoPro. Visibility sucked but I was underwater so I was happy. I cranked up the venturi slightly. Breathed fantastic - effortless actually. Mark

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Re: Argonaut DSV

Posted: Wed May 01, 2019 1:43 am
by Chris
Now that summer is peeking through the clouds, if any of you guys have not solved your hose flooding issue on your Kraken, might be your DBE valve sticking to your main diaphram. Look through the exhaust ports with a flash light after you get it wet and give it a breath. Mine would suction cup itself repeatedly. I did a trial fix of a small amount of silicone sealant (verry small line) on the main diaphram to prevent the mushroom valve from creating a suction. I have not had any issues since. Might be a better way, but as long as I'm dry, I'm happy.

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Re: Argonaut DSV

Posted: Wed May 01, 2019 11:51 pm
by Fibonacci
Thanks Tripplec that's certainly a possibility as my diaphragm showed quite heavy rub marks where both the exhaust valve and the standoff rib had impacted it.

The other thing we are investigating is distortion of the exhaust valve seat... positive indications so far.
Seems to mainly effect the Kraken as the DBE style housing is incorporated in the top can and has quite a thin wall section vs the main wall thickness. This will be tricky to mould as the different thicknesses cool unequally leading to sink marks and distortion.
Luis' light leak test showed it sealed very poorly!

Byran refaced the exhaust seat flat and so far the rapid hose flooding has not reoccurred, despite trying all the positions and breathing cycles where it previously gave trouble. Fingers crossed :)

Re: Argonaut DSV

Posted: Thu May 02, 2019 12:11 am
by Chris

Fibonacci wrote:At last some independent confirmation... thought mine was an isolated case!
So if it occurs on the Kraken, it should also occur on the DBE as they are virtually identical in design?
Looking back on some of these, I was curious about the difference too. The aftermarket DBE on my PRAM sits at an angle to the main diaphram. So it couldn't ever make contact all the way around like it can on the Kraken, being the Kraken is parallel to the main diaphram.

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Re: Argonaut DSV

Posted: Thu May 02, 2019 12:32 am
by Chris
Another thing you can check is make sure the mushroom valve hasn't come dislodged. This is a picture of mine. You can see the valve dislodged and still suction cupped to the main when I got home. I swapped out the mushroom valve with another one I had on hand that had a bigger barb.Image

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Re: Argonaut DSV

Posted: Thu May 02, 2019 1:27 am
by Fibonacci
Great sleuthing... thanks tripplec!
I didn't realise the subtle differences between the DBE and the Kraken's exhaust orientation.

I guess another fix would be to source a 33mm G250 exhaust valve that has either a centre boss or radial ribs that would act to break suction?
Or to add a boss to the diaphragm like the Snark III?

Re: Argonaut DSV

Posted: Sun Aug 11, 2019 2:42 pm
by ScubaLawyer
Used my DSV and HPR in stealth mode this morning and speared a 14 lb Halibut. :)

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