Replacing Exhaling Valve

[Nemrod]

Most of the hoses around a few years ago were the heavy EDPM rubber. Some were better than others. I actually have one set of the EDPM that I like. The vss Super Stretch hoses are also the EDPM rubber.

Then the "English" sourced neoprene hoses were available with mold marks and authentic colors. Then the "English" then source switched to silicone, the colors were a bit soft but still acceptable, still had mold seams and were now somewhat on the light side but, again, still excellent.

Then vdh came up with his current line of gray, green, black, yellow silicone hoses which are remarkably nice and the price is great too.

There are also now some gray and I think black neoprene hoses from vss that are very authentic in feel and weight.

That is sorta the incomplete history of recent hoseshenanigans. There have been a few minor players that offered bright yellow hoses and a few almost players.

And all of that without the history and evolution of modern duckbills, cage valves, nozzle bodies and mouthpieces. Perhaps some day there will be written a history of the history of the modern reincarnation of the double hose.

N

 

[halocline]

When I watched the video of the duckbill installation, I noticed that the one in the video was not as far into the can as mine is. I was just guessing on mine, but I imagined an "X" covering the edge of one slit to opposite edge of the opposite slit, so that the intersection was sort in the middle of the working part of the valve, and placed that point as close to the center of the can as I could. As far as trying to get the highest point of the top slit in the duckbill right on the center of the can, I don't think mine would do that without twisting it and fastening.

Of course, it's only in a completely vertical situation that this matters, correct? As soon as you're somewhat horizontal the duckbill will be lower than the diaphragm because it's resting against the can.

 

[INFIDELxx]

I agree with your statement about the top slit in the center. How can you do this without glueing the duckbill after pushing it down? It would then be twisted slightly. I do not think he means actually putting the slit in the center. But the "x" as you put it in the center. DId any of this

 

[Luis H]

Below is a picture of the general location where I like to install my duckbills. The rod crosses approximate across the center of the cans. There is a little error due to the angle of the picture.

The duckbill on the left is a new silicone duckbill from VDH, the one on the right is an older duckbill (left intentionally long from VSS). Both of them work great, the silicone should last a very long time, but the other one is holding up fine so far ( I do remove and inspect the non-silicone duckbill more often).

 

[rstofer]

I replaced the duckbill yesterday and I used a clamp ring to replace the C clips. I'm pretty sure I didn't have it quite so far into the housing. I'll take another look today. It should be a lot easier to play with this DA AM now that it has the clamp ring.

Richard

 

[Luis H]

The only reason to locate the duckbill that close to the center as shown is to avoid a free flow if you have a finely tuned RAM or PRAM. Most DA Aqua Masters are not tuned to that precision.


The silicone duckbill on the left should probably be glued to the can with some silicone glue so that it doesn't move around. Since the silicone will not stick to the horn like other rubber duckbills, it can be left in place unless there is a need to replace.

 

[pescador775]

Cousteau felt that the exhaust had to be located as close to the intake as possible. I interpreted this as relative to the diaphragm, or distance in line with the axis of the regulator. However, if a regulator were adjusted to near freeflow the lateral position, or angular position relative to the axis, could influence the regulator's performance. A diver leaning to the right (right side down) could result in the duckbill exhaust port being above (shallower than) the intake port. Apparently, performance has something to do with centering of the valve at the diaphragm and a lot to do with a depth differential of the valve and intake at a specific diver attitude. The question is where is the intake, exactly? It appears that the cavity behind the diaphragm has to be considered as an extension of the intake so it could be concluded that the the center of the diaphragm is the approximate location of the intake. IOW, the center of the diaphragm is the intake origin. I doubt that this would be important to most divers as Luis said. I cut the VDH silicone duckbill to 5.5 inches and overlap the material about 3/4 inch at the horn. I don't glue the valve outlet. However, I place some neoprene glue on the horn before folding the rubber onto it. I don't want that silicone valve to move after it is installed and I don't plan on removing it anytime soon. Also, before installing the hose I place a drop of Christolube on the exterior of the duckbill where it overlaps the horn. I guess my regulator intake suction is about 1- 2 inches. I don't like a touchy double hose regulator. I use factory settings with exception of IP which is raised from normal 110 to 135 psi. The biggest improvements are probably the VDH wagon wheels and silicone flutter valve or duckbill. All IMO, I have not experimented with valve positioning.

 

[Nemrod]

My two finely tuned RAMs will free flow, --bubble--bubble--------------bubble---------bubble-------------------------------------------bubble, if I roll a bit or go slightly head down. It breaks about .5 to .6 measured on my water manometer. I try to place the duckbill dead center at the apex of the slits. Essentially the same thing Luis is doing. If I don't put it in the center my RAMs will bubble.

I do use some Aqua Seal under the neoprene duckbill and a touch of silicone under the new silicone duckbill so that they do not get sucked into the horn.

I know Cousteau said the intake but I think he should have said center of diaphragm, that is what he meant IMO.

N