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Post by snark3 on Jun 29, 2021 10:37:25 GMT -8
Fred Roberts, in his book Basic Scuba, has a good section on how "J" valves work.
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Post by SeaRat on Jun 29, 2021 10:43:52 GMT -8
Fred Roberts, in his book Basic Scuba, has a good section on how "J" valves work. Yes, I’ve read that, but the Calypso-J has a really different design. Near as I can figure, the design does not require a spring behind the reserve mechanism, nor a ball. These are internal, where I thought there was simply an adjustable spring tensioner. It turns out this was not the case, and that the spring and seat are internal to part #36 (see the diagram). Screen Shot 2021-06-29 at 11.21.36 AM by John Ratliff, on Flickr It looks like mine are all missing on O-ring that is included in the mechanism too. John
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Post by nikeajax on Jun 29, 2021 10:49:43 GMT -8
I see looking in Basic Scuba that the Northill has a real j-valve mechanism as opposed to the goofy fake one, thanks for pointing that out Eb, that the Divair used.
JB
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Post by SeaRat on Jun 29, 2021 14:57:26 GMT -8
I also looked at the "Calypso Service Notes" on the VDH website for documents, and found this: I just tested my latest Calypso-J, and it is now functioning for the J-reserve. All it took was taking it apart, and putting it together again. I'm going to do that once more, and this time use some silicone spray to make it function better. John
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Post by scubalawyer on Jun 29, 2021 16:46:48 GMT -8
I see looking in Basic Scuba that the Northill has a real j-valve mechanism as opposed to the goofy fake one, thanks for pointing that out Eb, that the Divair used. JB JB, The DivAir does not have a J-valve at all. It is neither goofy or fake. It is simply a well designed and very simple mechanical reserve mechanism that works exceedingly well. My 2psi.
M
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Post by vance on Jun 29, 2021 16:52:11 GMT -8
DivAirs rule.
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Post by nikeajax on Jun 29, 2021 16:58:05 GMT -8
Mark, you fell for my eeevile trap MUUUU-HUUUU-HAHAHA! It was just a way of trying to get someone to post something PY, yer preaching to the choir: Divairs breath exceptionally well JB
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Post by SeaRat on Jul 2, 2021 21:59:06 GMT -8
Mark, you fell for my eeevile trap MUUUU-HUUUU-HAHAHA! It was just a way of trying to get someone to post something PY, yer preaching to the choir: Divairs breath exceptionally well JB I wasn’t going to reply to this one, as I recognized that the DivAir didn’t have a true J-valve. But I needed to do some research to figure out how the Calypso-J and the Scubair-J worked. It turns out that the two do the same thing, having an internal 300 psi spring inside the J-valve unit. But that is hidden, and is not adjustable or ever accessible. So now I have three functioning regulators with a J-valve. I may have four if I decide to put the J-valve mechanism from a aluminum valve based upon the AMF Voit J-valve (but made of different materials, and the J-valve doesn’t deteriorate like the AMF Voit one. So I’m close to conducting that experiment. Scubair-J parts diagram by John Ratliff, on Flickr John
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Post by cnotthoff on Jul 3, 2021 9:00:36 GMT -8
Last week, a customer dropped off his Calypso for service. He had purchased kits from VDS. Those kits had all the o-rings and a washer or 2, but no hp seat. So what are the new old stock seats I have worth? He also purchased a kit for the first stage US Divers marketed as a Calypso in the 90's. That one is an unbalanced piston, so not quite the same as the vintage one.
I've got a couple of the Calypso reserve mechanisms, as well. As Phil knows, I occasionally feel the need to send stuff off to people who might have a use for it.
Good Dives, Charlie
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Post by vance on Jul 3, 2021 13:54:28 GMT -8
And I appreciate it! Especially the man-o-manometer and the sh**-ton of mushroom valves. What some of the other stuff is? That's a mystery.
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Yawana Dive
Regular Diver
Diving the Solomon Islands
Posts: 45
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Post by Yawana Dive on Jul 3, 2021 19:08:58 GMT -8
I have one tank with a Jvalve. I don’t know what brand it is but the mechanism is like new and it works well. I’ve noticed quite a difference in its effectiveness depending on regulator I’m using. When diving with an unbalanced piston 1st like my Healthways Scuba Star with a downstream 2nd I can feel when the tank is down to about 300psi and time to activate the reserve. The breathing immediately becomes easier. But when I dive the same Jvalve with a diaphragm 1st like my Sportsways Hydronaut I really can’t feel when the tank is getting low and it’s time to pull the lever. I rely on the SPG in these circumstances. I’m assuming this is because the diaphragm 1st has an increase in ip as the tank pressure drops. Has anyone had a similar experience? Any thoughts?
Andrew
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Post by SeaRat on Jul 3, 2021 20:24:37 GMT -8
Hi Andrew, I've been diving a J-valve for decades, and have not noticed that difference between a piston and a diaphragm regulator on the J-valve. They both should be acting like you are out-of-air before the J-reserve lever is pulled. My third regulator was an AMF Voit Viking 40 Fathom, the same regulator as the U.S. Divers Company Calypso. It was a balanced diaphragm first stage, and downstream second. When I was in the US Air Force, we dove double 72s, with a Calypso regulator or a MR-12 regulator, both of which are balanced diaphragm regulators with a downstream second stage, and the J-reserve worked the same on those as any other regulator. 304th ARRSq historical002 by John Ratliff, on Flickr U.S.A.F. Pararescue Team from the 304th Aerospace Rescue and Recovery Squadron, preparing for a training dive in Yaquina Bay, Oregon in 1973 (I think; I'll have to check). I was the instructor for this set of dives. They are using twin steel 72s, with the U.S. Divers Company Calypso regulator (second generation, balanced diaphragm). Dave Ward is the PJ on the right. What I have found is that the J-reserve mechanism does need maintenance from time to time. My Calypso-J is now working, when it did not when I went to check prior to the test I'm about to conduct. The same is true of the Scubair-J regulator by Healthways. The mechanism can get caught up a bit, and make it not as effective, or completely ineffective. My Sportsways Sport Diver with the J-reserve works extremely well, and completely blocks flow at below 300 psi. So what I would recommend is to disassemble the valve's J-reserve, lube it, and put it back together (it's not hard to do). If you need schematics, let us know and someone is bound to have them. John
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Yawana Dive
Regular Diver
Diving the Solomon Islands
Posts: 45
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Post by Yawana Dive on Jul 3, 2021 21:12:41 GMT -8
Ok, maybe I’m just imagining things John. I’ll do another couple of comparison dives and report back.
Endless entertainment to be had with vintage gear....
Andrew
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Post by surflung on Jul 6, 2021 10:20:09 GMT -8
Eb, great write-up on your vintage dive weekend! Did you know that Bill Arpin designed the DivAir to work on double tanks/double manifold too? The L-shaped bracket that holds the lever is designed to be rotated 90 degrees to position the lever vertical to fit between twin tanks. You just have to reposition the screws holding the bracket into the pre-drilled alternate holes beneath the bracket. My 2psi. Hey Mark, Thanks for the tip. I really like diving the DivAir and was kind of disappointed not to use my Twins.
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Post by nikeajax on Jul 6, 2021 11:18:14 GMT -8
Thinking back on it now, I can visualize being able to turn the bracket, as well as the index marks to adjust the duration as I believe Fred Roberts called it...
JB
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