Constant flowrate air valve e.g. for switchgear - has free foil disc in chamber that responds to change in inlet pressure to vary flow cross section to give constant flow rate

摘要

The device has a cylindrical chamber within which is a circular metal plate[5] of smaller diameter and of a thickness less than that of the chamber. The chamber has an inlet [3] and an outlet [4] for air. Air applied to the chamber through one port [3] causes the disc to be displaced Air flows through the annular gap and if the inlet pressure increases so does the pressure on the topside This causes the disc to move and so reduces the size of the outflow path to maintain constant flow rate.