Vintage single hose

[Slonda828]

The only models of Conshelf that fall under the umbrella of "vintage diving" are the VI, XI, and XII.

They are all pretty much the same, except for the ports. The VI had the older style second stage with the smaller exhaust valve, and the first stage had 1 LP and 1 HP port. The XI has the bigger exhaust valve on the second stage, and the first stage has 2LP and 1HP ports respectively. The XII has 3LP and 1HP port, and the same second stage as the XI but with a better exhaust tee. Confused yet?

I would check VDH's forum for this type of information, it has been covered there numerous times. This part of SB is sort of a gateway drug to actual vintage equipment diving discussion which occurs at VDH.

 

[guadeira70]

you can see a lot of vintage single hose reg on sdhr.fr.nf www.sdhr.fr.nf

 

[DarthWader]

I am partial to the US Divers regs myself, and I have created and sourced repair kits for several. They are simple to fix and dang fine breathers if you can get them to hold a good high IP of 140-145. Pretty much any Conshelf can be made into a great reg even by today's standards, for example I have a Conshelf VI that holds a rock solid 145 psi IP with the new style teflon seat in it and is tuned to about 1 inch on the magnahelic. It does have the smaller exhaust valve, but in my opinion it is not noticeably harder to breathe with a good, high IP.

I have the following US Divers regulators and lots of spare parts if anyone is looking into rebuilding one, it is quite the enlightening experience and is pretty cost effective:

Conshelf VI
Conshelf XI
Conshelf XII
Conshelf XIV
Calypso J (IV series)
Aquarius

Parts are also availible for both styles of second stage. The VDH store carries rebuild kits for single hose regulators as I have time to create them as well.

I just picked up a Conshelf XI second. I was going to disect it, but after reading up a bit, I think I'd rather restore it. how are these regs for ease of service, parts, etc?

 

[Slonda828]

I just picked up a Conshelf XI second. I was going to disect it, but after reading up a bit, I think I'd rather restore it. how are these regs for ease of service, parts, etc?

Pretty much as simple as you can possibly get. It is an unbalanced downstream second stage. The only adjustment is via the locknut on the poppet, which controls both lever height and cracking pressure. It takes a moderately savvy person about 20 minutes to rebuild a USD second stage and maybe another 20 to tune it to precision with a magnahelic or a pan of water.

I use a conshelf, in one form or another, for all of my diving. Last weekend I dove to 120 feet with a conshelf XIV converted to 300 bar DIN, nitrox clean, with a 7 foot primary and a 22" bungeed backup. They may not be plush, but they will get you home and there is very little to fail on them. There is no user adjustable cracking pressure knob, venturi, blah blah blah. I have mine set at .8" for a cracking pressure and they breathe like a dream.

Rebuild kits are available (from me) on Vintage Double Hose. They are only 20 bucks, so I'm obviously not in it for the money.

 

[Greg Barlow]

I have mine set at .8" for a cracking pressure and they breathe like a dream.

I am very surprised that the reg doesn't free flow in a face down position. The CFG (case-fault-geometry) of my own restored Conshelf VI places the distance between the top edge of the exhaust valve approximately 1.3" from the center point of the diaphragm.

Considering that crititical measurement, an atmospheric pressure cracking effort of
1.2" (or less) should cause the diaphragm to be deflected inward. This would create a leak at the exhaust valve due to the variation in ambient pressure. Of course, this is only in the position of having the exhaust valve in such an orientation. If your body position moved out of the horizontal plane, it would then stop free-flowing.

When I tune vintage single hose regs, I calculate the worst case CFG and then adjust the cracking effort with a magnehelic to 0.1" above the minimum level. On most vintage metal second stages, this equates to around 1.2-1.4". For example, on a Voit MR-12, the cracking effort should be set to 1.3". While in a face down swimming position this allows a "true" cracking effort of around 0.2-0.3" due to the CFG. It is also completely stable.

It helps if you take a case and hold it in your hands while observing the position of the exhaust valve while in relation to the diaphragm. I have made this demonstration to other divers by removing the front cover so that they can see the parts while the case is rotated.

Some small bodied regs such as a modern Mares Proton Metal can have the cracking effort set to around 1.0" for the same worst case CFG. Once again, it all comes down to the geometry of the exhaust valve/diaphragm.

Greg Barlow
Former Science Editor for Rodale's Scuba Diving Magazine

 

[WD8CDH]

I use Conshelfs, a Calypso and Cyklons even for my "regular" diving. The Cyklons are my favorite except that they won't fit a 300 bar DIN valve. Fortunately, I don't use 300 bar valves, even on my HP tanks, which have 200 bar DIN/K valves. I never could find newer regulators that were much better or more reliable or easier to maintain than these.

 

[Slonda828]

I am very surprised that the reg doesn't free flow in a face down position. The CFG (case-fault-geometry) of my own restored Conshelf VI places the distance between the top edge of the exhaust valve approximately 1.3" from the center point of the diaphragm.

Considering that crititical measurement, an atmospheric pressure cracking effort of
1.2" (or less) should cause the diaphragm to be deflected inward. This would create a leak at the exhaust valve due to the variation in ambient pressure. Of course, this is only in the position of having the exhaust valve in such an orientation. If your body position moved out of the horizontal plane, it would then stop free-flowing.

When I tune vintage single hose regs, I calculate the worst case CFG and then adjust the cracking effort with a magnehelic to 0.1" above the minimum level. On most vintage metal second stages, this equates to around 1.2-1.4". For example, on a Voit MR-12, the cracking effort should be set to 1.3". While in a face down swimming position this allows a "true" cracking effort of around 0.2-0.3" due to the CFG. It is also completely stable.

It helps if you take a case and hold it in your hands while observing the position of the exhaust valve while in relation to the diaphragm. I have made this demonstration to other divers by removing the front cover so that they can see the parts while the case is rotated.

Some small bodied regs such as a modern Mares Proton Metal can have the cracking effort set to around 1.0" for the same worst case CFG. Once again, it all comes down to the geometry of the exhaust valve/diaphragm.

Greg Barlow
Former Science Editor for Rodale's Scuba Diving Magazine

Greg,

I was referring to the later model second stage with the 1 3/16" exhaust valve. The older second stage does seem to freeflow when set at a cracking pressure any lower than around 1.5-1 inch.

 

[Greg Barlow]

Greg,

I was referring to the later model second stage with the 1 3/16" exhaust valve. The older second stage does seem to freeflow when set at a cracking pressure any lower than around 1.5-1 inch.

I still am surprised, as the exhaust valve size has little bearing on the situation. Unless you are using a coaxial exhaust valve/diaphragm, it is difficult to tune a single hose reg to such a low cracking effort. If you are vertical in the water, or in a normal swimming position it is not much of an issue.

When face down, with the diaphragm on the same plane as the surface, most regs have at least 1.2" inches between the center of the diaphragm and the uppermost sealing point of the exhaust valve. This is the factor that manufacturers use when setting the cracking effort of a reg. Setting a cracking effort on a Conshelf of any vintage below 1.2" would have a free flow as the diaphragm water pressure is greater than the pressure exerted upon the exhaust valve.

Now, if you remained in the typical swimming position, a 0.8" would be feasible. Heck, given the laws of physics, if you never moved from the vetrical position, you could use a reg with a cracking effort of 0.4" or a bit less.

This effect is the reason why Scubapro used such an odd-looking case arrangement with the original Pilot second stage. It could be tuned to have a cracking effort of around 0.5-0.6" and never free flow in any body position. The D400 was built in the same manner.

As far as small bodied modern regs, the small Oceanic and Mares designs can typically be set pretty low without any such issues. That is because the distance from the diaphragm's center point and the exhaust valve is around 0.9-1.1" or so. Their only problem is that the relatively small size of the diaphragm reduces the mechanical advantage of a larger diameter version.



Greg

 

[hgoforth]

I am partial to the US Divers regs myself, and I have created and sourced repair kits for several. They are simple to fix and dang fine breathers if you can get them to hold a good high IP of 140-145. Pretty much any Conshelf can be made into a great reg even by today's standards, for example I have a Conshelf VI that holds a rock solid 145 psi IP with the new style teflon seat in it and is tuned to about 1 inch on the magnahelic. It does have the smaller exhaust valve, but in my opinion it is not noticeably harder to breathe with a good, high IP.

I have the following US Divers regulators and lots of spare parts if anyone is looking into rebuilding one, it is quite the enlightening experience and is pretty cost effective:

Conshelf VI
Conshelf XI
Conshelf XII
Conshelf XIV
Calypso J (IV series)
Aquarius

Parts are also avalible for both styles of second stage. The VDH store carries rebuild kits for single hose regulators as I have time to create them as well.

Assistance needed.
I have an old Calypso J that is in good condition except it has not been used for 20 yrs. I am the original owner. I tried to find a local dive shop that would restore it but to no avail. They can't get the original parts and they will not use any other parts (LDS requirements).
What can you suggest? I can't locate a repair manual on-line thus I can't do this myself.
I was an EOD Diver for 26 yr and understand how to work on the old DA and DA Royals but I have never repaired a Calypso J. Any advice would be appreciated...
FYI I would like to dive this regulator, the same as the DAs that Bryan at Vintage repaired for me.
Thanks in advance,
Hal Goforth, Jr.
email hgoforth@cox.net

 

[herman]

Assistance needed.
I have an old Calypso J that is in good condition except it has not been used for 20 yrs. I am the original owner. I tried to find a local dive shop that would restore it but to no avail. They can't get the original parts and they will not use any other parts (LDS requirements).
What can you suggest? I can't locate a repair manual on-line thus I can't do this myself.
I was an EOD Diver for 26 yr and understand how to work on the old DA and DA Royals but I have never repaired a Calypso J. Any advice would be appreciated...
FYI I would like to dive this regulator, the same as the DAs that Bryan at Vintage repaired for me.
Thanks in advance,
Hal Goforth, Jr.
email hgoforth@cox.net

Ron has stopped dealing in single hose regs due to a new work schedule but he may still have parts, try PMing him on VDH.
You can find the manuals you need here: File Downloads