dir or not dir

[Divesherpa]

You know Scuba Guy, I'm not DIR because I like to dive alone, as well as other reasons I will not name at this point.
As for arguing for or against DIR, you have to have practical knowledge of the protocols and gear before you can really have an opinion or you are just talking out of your a*%. DIR is preached as an all or nothing approach, but from an individual perspective, take what you can from it. It's an excellent starting point. After learning the system, improve on it and stray from it. Make it better. Don't just knock it (or those who practice it) with knowing what you are talking about. That adds fuel to the fire.

By the way, the carnivores you were thrown in with are starting to sound like GI3.

Ha, Ha


Just kidding.

 

[The Chairman]

you posed a simple query...

My question is.. has anyone heard of any reports backing up what DIR says??

So far, you have been labeled as...
"Having no idea..."
"Trying to start a flame war..."
One who "should do your own homework..."
"Having an aversion to getting wet..."
"A skeptic"
"A troll"
"A horse led to water..."
"A baiter"
"Pontificating with a big chip on your shoulder that is a snag hazard..."
And, being "full of it"!

While the theory for your question has been revealed (and quite nicely too), I don't think anyone here has any reports to back up that theory. If they do, they aren't very forthcoming with it. They have lots of theory, a great diving record, but are kinda shy on hard facts.

At least I am not the ONLY ONE to be attacked in such a manner, and for that I should be thankful. So ask your questions, be open minded as I once was, and be prepared for the jihad that comes when some think that their way of diving is being questioned. You can claim your innocence all you want, but they will not believe you. So back out, you are not welcome here either, and let them play by themselves. We have the rest of the board to roam through! Yes it sucks, but that is reality for you!

 

[WYDT]

Hi Netdoc...

I think the main problem here is that this person is in my (and obviously others) opinion not trying to have a "discussion". He's trying to fan flames.

You said...

I don't think anyone here has any reports to back up that theory. If they do, they aren't very forthcoming with it. They have lots of theory, a great diving record, but are kinda shy on hard facts.


DIR is not theory. You want hard facts??? What about world records in cave diving?? What about a perfect safety record for the wkpp since "DIR" was implemented by GI3?? What about 400+ft dives on the Brittanic? Cold water.. What about SCRET?? I could go on and on... Is that what he/you want?? Proof?? It's there for those who care to open their eyes.

The guys that invented this stuff do dives that most of us could only dream of and their methods and reasons have been explained ad nauseum here and in many other forums and sites.

So for some person to come here and question it without even knowing what it is might set us off a bit and I believe that was the original intention in the first place anyway.

No one is saying that if you don't dive DIR you will die. It does however in my opinion give you a better chance to live when the S___T hits the fan and I've NEVER heard of anyone who tried it that didn't agree that it was the best way to dive backmount. Hence the reason for posting all those links I did about the DIR fundamentals classes. BTW: Those were FUNDAMENTALS classes not TECH classes.

All we are saying is to try it or at least know a little about what he's talking about first.

He wants answers??? The answers have been out there for years.

 

[Jarhead]

There were these two preachers standing by the side of the road holding a sign. Written on the sign were the words "The End is Near". They noticed a rapidly approaching car and held up their sign so it could be read. The people in the car hurled insults and obsene gestures at the two men as they passed. After the car sped on around a curve, there were screams and a violent crash. One of the preachers turned to the other and said, "I told you we should and just printed Bridge Out on that sign".

That story has a lot in common with this thread (and the whole DIR/nonDIR situation).

I am not DIR.
DIR has alot to offer the diving community as a whole.
DIR is often not presented very well.

Jarhead

 

[omar]

So petey,

I see that you're back from licking your self inflicted wounds and stirring the pot again. I think that you need to give it a rest as well.

omar

 

[padiscubapro]

Originally posted by Rick Murchison
My, my, my... don't we all get emotional?
The original question may have contained bait, and most took it!
Omar, the cool head, extracted the diving question and answered it well, and didn't appeal to "DIR" once in his answer. Now that's the way to defend a position.
BZ Omar!
As for me, I buy the barrel o-ring manifold, for the reasons Omar stated.
Rick

I don't buy the "barrel O-ring" vs surface o-ring..

The Diverite, halycon and similiar manifolds that use the double barrel o-rings need the 2 orings, the isolator bar is not that hefty and the surface area of the orings is not that great.. Barrel o-rings are fine, I'd just rather not use them in a stress point if I could avoid it.

Captured O-rings like that used by OMS, have a much larger surface sealing area, and their isolator is very hefty, it can probably take more abuse than the others (Most people who use doubles know better than to carry the tank by the isolator, but you have to worry about others moving your eqpt this way).. If you are so against surface sealing captured o-rings what kind or reg are you using?? the method used by oms is the same that is used by your typical din reg...

I have both types of manifolds, I have had on of my DR one damaged by some idiot, the OMS one suffered no ill effects from the same person. Both designs work fine, I just feel the barrel type needs a better set of bands and more care when transporting..

 

[omar]

There are two typical o-ring seal designs, axial or radial. Axial is the OMS type, radial is the barrel type. O-Rings perform their sealing action by deforming to take the shape of the groove that they sit in and the sealing area is a function of the cross section diameter and the size of the groove, not surface area.

For the axial type you need to ensure that the o-ring will stay in the groove and will not fall out or twist in some unpredictable manner during assembly. In addition, the o-ring must be compressed by a predetermined amount.
This compression determines the o-ring cross-section diameter and is one of the design criteria. For this to work correctly every time the face seal must be compressed the right amount. How many people are aware of this that use the axial type manifold?

As I mentioned I use DIN regs which have the axial o-ring. I have had the o-ring protrude a couple of times when the reg was not securely screwed down. You see this also with the yoke type valves as well. Because of this I would not use this type of system in a manifold when I have a choice.

The assembly problems are much less with the radial design because it is addressed during the design of the o-ring groove and the diameters and variation (tolerance) of the parts. Try taking one of the o-rings off of the barrel style - It will still work. It does not need 2 to function.

omar

 

[padiscubapro]

Originally posted by omar
There are two typical o-ring seal designs, axial or radial. Axial is the OMS type, radial is the barrel type. O-Rings perform their sealing action by deforming to take the shape of the groove that they sit in and the sealing area is a function of the cross section diameter and the size of the groove, not surface area.

For the axial type you need to ensure that the o-ring will stay in the groove and will not fall out or twist in some unpredictable manner during assembly. In addition, the o-ring must be compressed by a predetermined amount.
This compression determines the o-ring cross-section diameter and is one of the design criteria. For this to work correctly every time the face seal must be compressed the right amount. How many people are aware of this that use the axial type manifold?

As I mentioned I use DIN regs which have the axial o-ring. I have had the o-ring protrude a couple of times when the reg was not securely screwed down. You see this also with the yoke type valves as well. Because of this I would not use this type of system in a manifold when I have a choice.

The assembly problems are much less with the radial design because it is addressed during the design of the o-ring groove and the diameters and variation (tolerance) of the parts. Try taking one of the o-rings off of the barrel style - It will still work. It does not need 2 to function.

omar

I agree the barrel style only requires 1 but due to the flex in some of those manifolds and variations in assembly the second is a good idea, not to mention the possibility of extrusion.. I don't see the captured Oring during assembly as a problem, you only assemble your units once a year for inspection or if you need to reclean them, just use a torque wrench and get it right everytime... If you have the right bands for your cylinders there is no need to have the placement of the isolator adjustable. The oms manifold uses a pretty large Oring that has reasonable tolerances. If there was a manifold (with barrel style) that the isolator was heavier in design than the current ones I would jump on it in a heartbeat.. I'm looking at the overall picture, the barrel style may be a more flexible and forgiving seal but the isolator on those current systems is pretty cheesy,so what you gain on one side you lose on the other because its just not as durabble. if you put that on the size isolator that OMS has that would be something.
Each manifold does have its plusses, ther is no perfect one yet..

 

[WYDT]

Originally posted by padiscubapro

I'm looking at the overall picture, the barrel style may be a more flexible and forgiving seal but the isolator on those current systems is pretty cheesy,so what you gain on one side you lose on the other because its just not as durabble. if you put that on the size isolator that OMS has that would be something.
Each manifold does have its plusses, ther is no perfect one yet..

Have you checked out the Divers Supply/Halcyon/Dive Rite manifolds (they're all the same)? They are pretty heafty and at least as heafty or more so than any OMS I've ever seen.

I have two of the Divers Supply manifolds I've been very happy with. Never had a moments problem on either one. I recently sold a Genesis manifold that was more "cheesy" as you say in it's isolator construction.... that and I hated the angled valves!!

DSAO!!

 

[padiscubapro]

Yes, I have one thats from diverite and one from divers supply, The OMS rig is definately more substantial. I also have an old sherwood (about 14 years old without any failures - and I hit the isolator once when using a scooter (open throtttle)when I misjudged an overhang)its also uses a face oring) and a genesis manifold.. in total I have 6 sets of doubles... 95s and 104s