Pneumatic regulating valve

摘要

The invention is an improvement in a pneumatic regulating valve of the type having a main flow path and a bleed passage. In the improvement, the bleed passage is in parallel with the main flow path and regulates a downward-trending pressure at the outlet port to prevent such pressure from diminishing or from rapidly diminishing. The valve also includes a check valve in series with the bleed passage for regulating an upward-trending pressure at the outlet port. Using a constant bleed orifice to substantially pressure-balance the check valve and a small-area protrusion on the check valve to reduce contact area, the check valve exhibits very low hysteresis.