conshelf regs

[Rich Keller]

I think it is the other way around.

But, do you really think anybody other than a handful of people know what a Kirby Morgan is? They are not stocked at the local LDS and the Tech Forum does not extoll their virtues. Nah, despite the Conshelf being, best I know, used by more commercial, military and science/working divers they just have no panache and are now orphaned.

N

These regs were being used in the KMB-8 starting in 1967. US bought Kirby Morgan in 1969 and started making the conshelf 11s in 1970 and the 12s in 1972. US bought KM for their inventions & patents that were used in their sport diving equipment as well as starting their commercial diving equipment line. Prior to that they just made sport diving equipment. The fact that few know what a conshelf reg really is, makes them about half the price of scubapro regs from the same era on ebay and they are every bit as good. The parts on the 12s & 14s are interchangeable, the 14s are still in production and sold through commercial diving suppliers so parts are never a problem to get either.

 

[Luis H]

You are missing a bit of the Conshelf history. The Conshelf VI came out in 1965. The only significant differences between the Conshelf VI and the Conshelf XIV are the number of ports in the first stage, the yoke strength and the exhaust valve diameter in the second stage. There were some other cosmetic differences (the looks of the front cover changed a bit), but no other functional difference.

The Conshelf first stage is the same as the Royal Aqua Master DH regulator (which came out around 1964 as the Royal Master).

As far as I know, the Conshelf VI second stage design predates the KMB-8 by a few years.

When I worked at Divers Service Center (1971 to 1978) I serviced a lot of Conshelf and did many dives (and serviced) a KMB-8. There is no question that they are basically the same second stage (with the modification for the adjustable second stage on the Band Mask).


Note: We actually had two Band Mask, but I think one might have been a KMB-9 (in the early to mid 70's). I don't remember the differences or which model numbers we had. I just remember that one was newer than the other.

 

[deeper thoughts]

posted on wrong thread sorry

 

[Rich Keller]

The main difference between the KMB-8 and 9s was the side block not the second stage. The side block on the 9s had a better check valve and bigger knobs for the valves but other then that they were the same.

 

[Luis H]

Thanks.

Yeah, we must have had one of each. I don't remember a lot of details, but I do remember that the knobs were different.
I think the newer one had the same plastic knobs as in US Divers valves (in the 70's).

 

[Nemrod]

I am sure, that like any company purchasing another, that elements of the KM were incorporated into the the USD line of regulators, however, the Conshelf name, basic design predates and the first stage used in the Conshelf (and basically in most USD and AL regulators to this day) is from the Royal Aqua Master/Royal Master double hose and like Luis said, that dates about 65. Yes, I am sure that USD incorporated KM features into the product line.

Comparing the SP109 to the Conshelf, the Conshelf has a slightly, to me, more simple second stage lever design and a larger exhaust valve, 30mm (vs 25mm for the 109) and larger exhaust tee which noticeably reduces exhalation back pressure. The first stage can be enviro sealed (Supreme) and though I am not a cold water diver (brrrrr) it is likely a better first for that purpose. The Mk V I am certain can flow more air, the piston design ambient chamber is open to seawater, this can on occasion be an issue, not one I am especially concerned with.

So, I am going to stay with what I said, the KMs you are fond of are an evolution of the USD Conshelf (and KM design) regulator, not the other way around. I could be wrong and if so, you will have to show me .

I have dove with KMs, they were very common around Houston during the time I lived there, perhaps because of the commercial diving school there and commercial diving in general being big in that area. Conshelfs were so common that they were kind of the default/generic regulator, everybody had them.

N