Apeks DST 5 port orientation on doubles for cave diving

[jadairiii]

@jadairiii it depends on how aggressive the second stages are set. If they are backed off enough, you can plan for it with IP and cracking effort settings, but it's not ideal

Like I said, never had that as an issue, but when I rebuild mine I set the IP at or just below recommended.

 

[kensuf]

Odd, never heard or seen this happen. My original Tech instructor only used the DST's, my mix instructor only used the DST's and I went exclusively to DST/DS4 in '99. Of that group, never saw it happen (with thousands of dives deep on those regulators by those 2 guys). I also know a lot of WKPP guys that have used them deep without issue. Add to that, both of those unnamed instructors, maintenance was not a "high priority" with them.

Now, I am not doubting you here, but, I would not immediately go and condemn the seal if I had free-flow deep. Plus, I'm having a hard time trying to figure out how the plunger/seal would give too much "feedback" at depth? (I read the article linked)

Add to that, the linked article seems to say the issue is with those first stages and AIR 2's? And the author claims his first choice 1st stage is the Mares MR22? Mares?

The author's eccentric, but he's right on this point with the IP creep.

You won't see a problem if you're using a balanced second stage, unless you're going REALLY deep, because the balanced second stage compensates and locks the seat down hard. If you're using an unbalanced second stage, or you're using the Apeks with environmental seal as an inflation bottle (or oxygen feed on a CCR),you will either get a freeflow or see an OPV pop.

The two freeflows I had were when I was using an unbalanced second stage on my backup reg. Both were when I went deeper than 230/240'.

We've also seen a number of OPV's on oxygen regs go pop at 100m in Twin Dees. Once the unit gets shallower, the OPV re-seats because the IP goes down. The solution to those was removing the environmental seal.

BTW, I had some of the same mentors / dive buddies as you a looooong time ago.

 

[jadairiii]

...

The two freeflows I had were when I was using an unbalanced second stage on my backup reg. Both were when I went deeper than 230/240'.....

HA! I remember that time when the consensus was to have an unbalanced back up.....who was preaching that? Anyway, I too did that for a spell but with Poseidon or SP first stages. When I converted to Apeks, I stopped that "unbalanced backup strokery...."

 

[kensuf]

HA! I remember that time when the consensus was to have an unbalanced back up.....who was preaching that? Anyway, I too did that for a spell but with Poseidon or SP first stages. When I converted to Apeks, I stopped that "unbalanced backup strokery...."

I blame Trey for all my past foibles.

 

[stuartv]

I'm sorry, but this article makes some blanket statements that are just not correct. And the fact that the author is from "scuba engineering" lends credence that he shouldn't have, based on what I read there.

I believe the author of that article is Mark Ellyatt, who does have some reasonably significant deep diving credentials. I believe Mark was thanking someone from ScubaEngineer.com for their consultation. Mark is not from ScubaEngineer.com. I believe Mark held the world record for depth on scuba at one point (313m), before it was later broken by Numo Gomes (318m - and that's been broken since). And Mark is still around to talk about it, unlike some depth record seekers.

Even if you don't buy all the details, I thought Mark's autobiographical book, Ocean Gladiator, was a pretty darn entertaining read.

 

[rsingler]

I believe the author of that article is Mark Ellyatt, who does have some reasonably significant deep diving credentials. I believe Mark was thanking someone from ScubaEngineer.com for their consultation. Mark is not from ScubaEngineer.com. I believe Mark held the world record for depth on scuba at one point (313m), before it was later broken by Numo Gomes (318m - and that's been broken since). And Mark is still around to talk about it, unlike some depth record seekers.

Even if you don't buy all the details, I thought Mark's autobiographical book, Ocean Gladiator, was a pretty darn entertaining read.

Thanks for the clarification!