Hatul
Contributor
That looks like a nice attachment for the bolt snap. Can I ask you exactly how you did that?
Regulator Second Stage Hose Swivel
- Thread starter BoltSnap
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
That looks like a nice attachment for the bolt snap. Can I ask you exactly how you did that?
lindenbruce
Contributor
Yes, this is on my primary second stage. When I ran a short hose I routed it under my right arm and straight up the front of my chest. I run a long hose now in the typical Hogarthian routing. My secondary second stage is on a necklace around my neck. The long hose gets donated if necessary. The bolt snap is attached using an o-ring and a zip tie. B
akeegan2
Registered
Atomic also said they service their swivel when you send their equipment in for service. That's good, because I would never let anyone but Atomic service my Z2X. A bit too complex for me, and what better than factory service.
axxel57
Contributor
Does anybdy knows why my post with the swivel flow tests and posts others from the 24. and 25.12. has been deleted from this thread?
---------- Post added December 28th, 2012 at 08:00 AM ----------
Does anybody know why my post with the swivel flow tests and posts from others from the 24. and 25.12. has been deleted from this thread?
---------- Post added December 28th, 2012 at 08:02 AM ----------
Does anybody knows why my post with the swivel flow tests and other posts fromm the 24. and 25.12. have been deleted from this thread?
---------- Post added December 28th, 2012 at 08:04 AM ----------
Sorry, double posted....
---------- Post added December 28th, 2012 at 08:00 AM ----------
Does anybody know why my post with the swivel flow tests and posts from others from the 24. and 25.12. has been deleted from this thread?
---------- Post added December 28th, 2012 at 08:02 AM ----------
Does anybody knows why my post with the swivel flow tests and other posts fromm the 24. and 25.12. have been deleted from this thread?
---------- Post added December 28th, 2012 at 08:04 AM ----------
Sorry, double posted....
axxel57
Contributor
Well, okay, found the announcment about the corrupted data here on this thread at the 21.12
Just in case somebody did not read my post in this time, here another chance.........
I don’t remember well anymore when the swivels came on the market in the nineties, but I remember that I was getting me one in the moment I heard about it.
I was working in East Africa where we had sometimes strenuous conditions, waves and currents , and I always felt a bit vulnerable when customers got stress, so I changed my regulator configuration and got a longer hose under my arm with a swivel.
At this time there was already a discussion about benefits and flaws of swivels. Some manufacturers claimed that it was even dangerous to use those swivels (at least the 360’swivels). I read this in a German Dive Magazin, but don’t remember which manufacturer was quoted.
I used one of the 120’ elbow swivels, but when the 360’ swivel came up I tried them on my octopus and found it even more valuable than the one for my primary 2nd stage.
Even in turbulent diving condition it was virtually impossible to come in a situation where because of a change in position between donor and receiver the octopus could get bended out of the mouth because the octopus with the 360’ swivel would go in any necessary position.
Since 1995 I think I have been working with this regulator configuration, and even today not working as a full time instructor anymore, I would not change it.
Around 70 of my dives I did at 200’to 330’feet, I never had a problem with those swivels. I could not tell from my feeling while diving if this configuration might create a significant degradation of the performance of the 2nd stage, because I was only diving like this, but this claim simply didn’t feel right to me. If there was a degradation in performance, it must be a minor one.
I don’t know how SP was testing which swivel, but since years I’m diving with a SP 120’ swivel.
Maybe their swivels are much safer than those of their competitors -J.
I would be interested if ever any diver had a bad experience with using any kind of swivel.
Anyway, with this topic coming up on this forum I did some tests with my flow module to see if there was any difference in performance while testing first and second stages flow test conditions.
I used a SP MK25 with a S600 2nd and a MKII with a R295.
I tested six different configurations:
1. No swivel
2. SP 120’swivel
3. The 120’swivel I started with about 17 years ago
4. 360’swivel in worst case position ( extreme elbow)
5. 90’swivel at the first stage
6. 90’swivel at 1st stage plus 360’ swivel in worst case position ( extreme elbow)
The test would be done and noted at 5 SCFM, 7.5 SCFM, 10 SCFM, 12.5 SCFM and 15 SCFM which put quite some strain on all regulator parts of the 1st and the 2nd stage while on flow.
Any problems of air flow because of restriction whatsoever in the regulator system should be seen by changes in cracking effort under flow (CE) or differences in the dynamic intermediate pressure ( Dyn. IP) or in changes of the performance of the Venturi Assist.
I guess there are anyway only few interested how these flow tests work, so I don’t go deeper in that, but what is obvious, is that the numbers are so close that there cannot be talked of a serious degradation of the performance at least of these two regulators.
My opinion:
If you like the swivel configuration, just do it , no worries.
Thanks for reading.
Just in case somebody did not read my post in this time, here another chance.........
I don’t remember well anymore when the swivels came on the market in the nineties, but I remember that I was getting me one in the moment I heard about it.
I was working in East Africa where we had sometimes strenuous conditions, waves and currents , and I always felt a bit vulnerable when customers got stress, so I changed my regulator configuration and got a longer hose under my arm with a swivel.
At this time there was already a discussion about benefits and flaws of swivels. Some manufacturers claimed that it was even dangerous to use those swivels (at least the 360’swivels). I read this in a German Dive Magazin, but don’t remember which manufacturer was quoted.
I used one of the 120’ elbow swivels, but when the 360’ swivel came up I tried them on my octopus and found it even more valuable than the one for my primary 2nd stage.
Even in turbulent diving condition it was virtually impossible to come in a situation where because of a change in position between donor and receiver the octopus could get bended out of the mouth because the octopus with the 360’ swivel would go in any necessary position.
Since 1995 I think I have been working with this regulator configuration, and even today not working as a full time instructor anymore, I would not change it.
Around 70 of my dives I did at 200’to 330’feet, I never had a problem with those swivels. I could not tell from my feeling while diving if this configuration might create a significant degradation of the performance of the 2nd stage, because I was only diving like this, but this claim simply didn’t feel right to me. If there was a degradation in performance, it must be a minor one.
I don’t know how SP was testing which swivel, but since years I’m diving with a SP 120’ swivel.
Maybe their swivels are much safer than those of their competitors -J.
I would be interested if ever any diver had a bad experience with using any kind of swivel.
Anyway, with this topic coming up on this forum I did some tests with my flow module to see if there was any difference in performance while testing first and second stages flow test conditions.
I used a SP MK25 with a S600 2nd and a MKII with a R295.
I tested six different configurations:
1. No swivel
2. SP 120’swivel
3. The 120’swivel I started with about 17 years ago
4. 360’swivel in worst case position ( extreme elbow)
5. 90’swivel at the first stage
6. 90’swivel at 1st stage plus 360’ swivel in worst case position ( extreme elbow)
The test would be done and noted at 5 SCFM, 7.5 SCFM, 10 SCFM, 12.5 SCFM and 15 SCFM which put quite some strain on all regulator parts of the 1st and the 2nd stage while on flow.
Any problems of air flow because of restriction whatsoever in the regulator system should be seen by changes in cracking effort under flow (CE) or differences in the dynamic intermediate pressure ( Dyn. IP) or in changes of the performance of the Venturi Assist.
I guess there are anyway only few interested how these flow tests work, so I don’t go deeper in that, but what is obvious, is that the numbers are so close that there cannot be talked of a serious degradation of the performance at least of these two regulators.
My opinion:
If you like the swivel configuration, just do it , no worries.
Thanks for reading.
halocline
Contributor
Actually, the long hose increases regulator performance, at least theoretically....I've never been able to tell any real-world difference. The reason is that the long hose effectively increases the volume of the IP chamber, so when you take a breath, you're drawing on a larger reservoir of IP air. This makes IP drop less during inhalation.
I usually go with your diagnosis Dr. Halocline and I agree that initially the larger (compressed) volume will decrease IP drop until (at depth) the volume is decreased relative to the flow requirements at which point, a long hose is a restriction as might be a jumble of fittings. But as seen, again, and again, for even deep technical diving, neither the elbow or the long hose have been shown to decrease breathing to the point that the human requirement is not met. I may not be saying it the best way, but I will stay with it. Once a high rate of flow is required there is no static reservoir to draw from, the hose is now a restriction, not an (extra) reservoir.
N
halocline
Contributor
The thing is, it's inescapable that less IP drop=better 2nd stage performance, and that flow is inversely proportional to pressure in a given space. Since you're presumably drawing the same volume of air from the 2nd stage regardless of hose length (enough to fill your lungs) if you're drawing it from a larger volume of reserve (the IP chamber) then that chamber must drop pressure less, and therefore flow more, than it would from a low volume chamber.
I think the tough thing to get our heads around in this is the feeling that the gas has to 'travel' a longer distance from the 1st to 2nd stage with the long hose, and is therefore going to get restricted due to friction. But it doesn't really work like that. One thing is that the air does not need to go any faster through the long hose. Imagine that each breath is the equivalent of 1 linear foot of hose at IP. With a 2 foot hose, you'd have to replace the air in the hose every two breaths, but with the long hose, only every 7 breaths. I'm not saying that gas moves exactly that way, like a liquid would, but it might help visualizing it. The important thing is the pressure. Less IP drop equals more flow every time and lower cracking effort. The air's not getting 'pushed' from the 1st stage, the entire hose is a pressure chamber.
The swivels and elbows are totally different. I don't know how they're internally constructed because I've never used one, but if they restrict the diameter of the gas path, sure, they'll at least theoretically slow it down. But it's not like in plumbing where every elbow restricts water flow. There's way way more friction in liquid movement than in gas.
How much of this matters in the real world is a different story, but this is the internet!
I think the tough thing to get our heads around in this is the feeling that the gas has to 'travel' a longer distance from the 1st to 2nd stage with the long hose, and is therefore going to get restricted due to friction. But it doesn't really work like that. One thing is that the air does not need to go any faster through the long hose. Imagine that each breath is the equivalent of 1 linear foot of hose at IP. With a 2 foot hose, you'd have to replace the air in the hose every two breaths, but with the long hose, only every 7 breaths. I'm not saying that gas moves exactly that way, like a liquid would, but it might help visualizing it. The important thing is the pressure. Less IP drop equals more flow every time and lower cracking effort. The air's not getting 'pushed' from the 1st stage, the entire hose is a pressure chamber.
The swivels and elbows are totally different. I don't know how they're internally constructed because I've never used one, but if they restrict the diameter of the gas path, sure, they'll at least theoretically slow it down. But it's not like in plumbing where every elbow restricts water flow. There's way way more friction in liquid movement than in gas.
How much of this matters in the real world is a different story, but this is the internet!
Go take your long hose rig and a install an IP gauge at the second and at the first. Draw a breath. The initial IP drop difference between gauges will be very small, do the same with a short hose and the initial IP drop difference will be slightly greater. Now, with the IP gauge still at the second and first stages. Hit the purge and hold it open, do it with both short and long hoses, compare the result during sustained flow. Now, take it down five atmospheres. Sorry, right now I only have the Y pool and it is 12 feet and the University pool is only 18 feet.
N
N
Similar threads
