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Post by seakrakken on Dec 7, 2005 2:00:36 GMT -8
Nemrod, I'd like to let you know right now that your contributions are valued by me and I'm sure by Buzz. He is also a proponant of the idea of a pilot servo valve system. It has many merits and may very well become the chief design componant on this project collaboration. When Buzz and I started our email conversation it was suggested that we should survey and canvas our peers/market for what they were interested in having in a double hose reg design. Possibilities range from a simple repro to something completely new. I'm not worried if it's not "Vintage" or if it's going to be blessed by CE or PADI or SSI or any other Org. This is for us and I'm not worried if we make six or six thousand. I care only if it satisfies our desires. If a servo valve reg does what we want and it can be made into a double hose reg then so be it. I'd like to see it. If it can pump air in high demand scenarios it may be usefull in other applications other than "Sport" diving.
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Post by seakrakken on Dec 7, 2005 2:04:44 GMT -8
I'd like to add the possibility of having a mesh membrane added into the inside of the exhaust half of the air box so that instead of having large noisy exhaust bubbles we get only a low signature hiss of tiny bubbles. Just a thought.
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Post by Ron Hearn on Dec 7, 2005 8:40:20 GMT -8
Thay may effect air flow wouldn't it.
Ron
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Post by duckbill on Dec 7, 2005 9:40:10 GMT -8
I do understand that the pilot valve system is not for primary air delivery. I meant regulator in the technical sense. I just had a funny thought about how the single hose could have evolved from the double hose via this concept. A double hose with a pilot valve could be viewed as an intermediate form.
I just don't know how far one could go trying to get the best of both worlds without also incorporating the faults of each system and overcomplication. Simplicity has it's merits. But I can see now how the regulator could be designed to deliver very high volumes of air and would need some mechanical advantage to do so- hence the pilot valve. I guess I just hadn't thought through the high-volume potential using the pilot. I would suggest, however, that any servo-assisted/pilot-valved double hose regulator should be designed to continue functioning should the servo-assist fail.
I have already put in my vote regarding hoses and mouthpiece. As far as the regulator proper, I would vote for HP and LP ports in the current thread sizes, incorporation of ready-made, readily available parts, balanced two-stage. I don't have any specific design suggestions.
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Post by seakrakken on Dec 7, 2005 14:52:28 GMT -8
Whether it would affect air flow using a mesh on the exhaust would depend on the surface area of the diaphram. I'm thinking something along the lines of the second diaphram as senn on the Dacor regs. Instead of having a rubber diaphram with a mushroom valve in the middle use instead a mesh screen from which all the bubbles would come from. I think the rebreather crowds use something like this on their Semi-Closed Rebreathers which vent some gas. The idea is just to muffle the sound of the bubbles by breaking them up into smaller size. The desired end result would be a hissing Alka-Seltzer like sound.
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Post by mossback on Dec 7, 2005 16:24:50 GMT -8
Hey you guys.........don't take away part of the magic of the doublehoser..........those noisy bubbles behind ones head are part of the Sea Hunt ambiance.
yeah, single hoses make way too much noise and their next to ones ear..
.but that soft bubble from behind ones head when using a double is music..............
.now the inhale sounds off the second stage could be quietn'd a bit.........mine sounds like a old rusty steel door opening, I think the second stage spring resonates too much......
if you have a penchance of sneaking around underwater, then by God, use a rebreather.
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mudhog
Regular Diver
Posts: 18
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Post by mudhog on Jan 1, 2006 14:15:35 GMT -8
I have reread this several times, keeps the little gray cells exercised!
Seems to be there are really two regulators being talked about here mostly.
1: Something US Divers might have produced in the 1980s if demand had been strong enough to continue Made in the USA double hose production but not strong enough to fund real development. So a simple redesign to use more current parts, as in Conshelf.
2: Strong demand, as in one third or more of all regulators sold by USD. Development to improve the double hose concept to surpass any single hose in overall performance.
Number one has been well covered so far and the 2nd has had some great brainstorming. Seems to be the first order is to get the 2nd stage as close to the lungs as possible, chest mounts have been done and while on the right track they look like they would make it cumbersome to doff and don your gear.
Why not design a new back pack that mounts the regulator in the best position on the back? Not talking about a shell style unit (though a shell could be made for those who wanted one), more a pack that integrated/located the regulator for best position, the can might even touch the back on some people. Would work well with twined tanks. A backplate could be modified for prototype work.
Optional, a device that would divert exhaust air to a BC bladder built in to the system.
I think the Cousteau units were started on the right track, problem is they were mostly styling exercises for PR value instead of "function first" units.
On another train of thought:
I figured out the area of my conshelf mouthpiece airway(?) and a 3/4 inch bore hose would have a larger cross section, so why are the standard hose sizes inch or larger? If a certain air volume is needed for proper regulation then a smaller hose would allow the regulator to be mounted further down the back and closer to the lungs.
Now heres your chance to blow holes in my ideas!
Thoughtfully: Mudhog
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Post by SeaRat on Jan 1, 2006 15:52:09 GMT -8
I have reread this several times, keeps the little gray cells exercised! Seems to be there are really two regulators being talked about here mostly... On another train of thought: I figured out the area of my conshelf mouthpiece airway(?) and a 3/4 inch bore hose would have a larger cross section, so why are the standard hose sizes inch or larger? If a certain air volume is needed for proper regulation then a smaller hose would allow the regulator to be mounted further down the back and closer to the lungs. Now heres your chance to blow holes in my ideas! Thoughtfully: Mudhog The idea for a smaller hose and mouthpiece were tried, and failed, in the Healthways SCUBA Delux and the Sportsways Hydro-Twin and Dual-Air. The problem isn't the diameter of the hose, or the diameter of the mouthpiece at the diver's mouth, it is the diameter of the non-return valves and the web that is needed to hold it that restricts the air. I proved this by taking a Healthways mouthpiece system, and carving out the non-return structure so that it was completely free of the non-return. This greatly increased the breathing characteristics of the regulator (decreased suction effort, much better venturi, and more air). SeaRat |
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mudhog
Regular Diver
Posts: 18
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Post by mudhog on Jan 1, 2006 17:35:05 GMT -8
So what needs to be built is a mouthpiece with big one way valves, seems a two piece design could do that. What happens when you don't use a one way on the inlet side, the thinking being one valve is easier to design around than two.
Oh, and what diameter are the valves usually? Only one I have to look at is a Conshelf one and it measures 1.2". Would think it would take a 1.5" to make a noticeable improvement.
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