Building Oxygen trapeze

Hello All

These days i have started to build an oxygen trapeze, I will be happy to get some recomendations and ideas about the structure of the the trapeze. like where to locate the first stage, outside the water on the oxygen tank or in the water, if it is in the water should i use one first stage ( ballanced) or two.

There will be four second stages with option to another two.

Another questioni, should i use different second stages in the different depth or i should i use the same second stage all the way ( in all the deco stops).

One more thing that is not related to the trapeze, I heard of an unusual case that in the depth of 100m the mouthpeace seperates from the second stage bacause the rubber gets squeezed by the pressure and the band does not holds them together, has aneyone else had a such a problem ?? Im using a couple of Aqualung legend regs, and this phenomenom never happened to me but if these things happen , it is something to think about..

thanks

Mark

What is an oxygen trapeze? Are you talking about a deco station with bars and surface supplied O2 that you would hang off the side of a boat?

thats the one

Make sure you have a check valve between the cylinder connection and the supply line. In the event an empty cylinder need to be switched for a full one, you will not be put in too uch of harms way. I person I know had this happen with out the check valve, and the negitive pressure made his face look like hamburger(he was using a FFM).

Kevin

I prefer a tank on the surface because with four positions you could be using a lot of O2, and it's a lot easier to occasionally wrestle a big K tank into the boat (though this of course depends on how big the boat is!) than be switching smaller UW tanks all the time, to say nothing of the hassle of getting small tanks transfilled on a regular basis. Also depending on whether you have a Haskel and/or O2 cascade, or what you LTDS charges for transfills it is usually a whole lot cheaper.

You can use a cheap second hand industrial/welding/medical regs only be sure it has enough range to supply the regs with their proper IP - a lot of cheap welding regs go only up to 80-100 psi which really isn't enough, 160 is better and 200 ideal.

It's nice to have a little headroom on the output so you can compensate for depth since the surface supply reg will be seeing surface ambient which will have the effect of reducing the IP to the 2nds if you don't. Lot of people don't bother since at 02 depths it doesn't make that much difference (rule of thumb 1 psi for 2') but its nice to have the option, especially if you are using junk box seconds.