Originally Posted by MaD
So one thing to think about is the size of the valve face. Not sure what would be optimal but it's been pretty well proven that a larger valve face allows for lower pressure. Actually, a large valve face may require lower pressure as the high pressure gas pushes the valve closed more quickly.
I realize most of this relates to sheridan / cocker valve setups and gas flowing through a powertube is a bit different than out the side of the valve but I think that some of the designs might have some application here.
Jack has gone down to I think 350 or 400psi operating pressure with current designs.
I think using a cocker valve spring, a hard one, that between the preload because the spring is longer and the harder spring we are going to be able to run low pressure without having to increase the face of the cup seal at all.