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Does anyone have any idea as to the extent of pressure cause by an elastic bladder? Specifically, I'm interested in the amount of pressure normally generated by a mid-size cylindrical elastic bladder (like that in a CPS 4100).

With air-pressure applications I can easily calculate these sorts of things, but I'm lost when it comes to elastics! I'm curious because I am currently building a CPS homemade and many of the valves are being made from scratch in order to save weight and increase customization. If I know the maximum PSI generated by a full elastic bladder, I can determined which materials I want to use in construction.

Thanks!

I measured the pressure of latex tube from McMaster-Carr (5234K53, specifically) at 23 psi if I recall correctly. This tube had a reported pressure of 35 psi. I believe that pressure refers to the minimum pressure needed for expansion. Once that pressure is reached the tube expands and the pressure drops, so the "effective operating pressure" (or whatever we should call it) is lower.

The 1998 CPS series had pressures printed on their boxes. I however can't find any box photos at the moment.

As I recall, no CPS blaster has a pressure that is over 40 psi. Design for 80 psi or so for a safety factor of two and you shouldn't have any significant issues.

I think an article on SSC said that the CPS 2000 operates at 60 psi or something. I'll go check.

EDIT: 45 PSI actually. This is what the Super CPS article on SSC said.

For comparison to existing water guns, water guns like the CPS 1000 operate at about 25 PSI. The CPS 2000 operates at 45 PSI. The first layer of this water gun operates at 35 PSI, and adding another layer increases that pressure beyond 50 PSI. The higher pressure is the source of the improved performance of this water gun.

Perfect, that's exactly what I was looking for! I figured it would be less than 50 psi, but I wasn't sure.

Thanks guys!