Clever design, I assume you have not suffered any O-ring failures during the venting process?.... I know that slide-checks are problematic when used on HPA at pressures higher than CO2.... That looks like quite a large diameter pin, how hard is it to unscrew the knob when under pressure at 2000 psi?.... Have you tried it at 3000 psi?.... What is the source?.... Is there a maximum safe pressure rating stated?....Bob