I still can't get out of my head using an air actuated pinch valve for the this.? ?However this requires a larger ID as the exhalation must pass through the tube instead of between the tube and the ID of the PVC pipe.? Besides you should? get many more cycles pinching more so than expanding .? ?This brings me to the question about what diameter of standard tube ( yes you can get any dia at many custom extruding houses, but time is in short supply)? ?I took a closer look on of the shelf parts at various supply houses and most are stocking smaller ID.? However it looks like McMaster stock silicon tubing in 60 & 70 Duro ( softness) in ID's up to 1.5 inches.? Just shooting from my hip I would think 1 1/4 inch ID? would? be OK, but I need to ask first.? ?To make sure I am on the right track? is my assumption of 1 1/4 inch ID ( over about 3 inches lenght) or do we need larger?
Rolf K9DZT
