Differential pressure regulator

Claim 1

A differential pressure regulator for maintaining the pressure of a controlled gas upstream of the regulator a predetermined and constant amount above the pressure of a reference gas, said regulator comprising: a first continuous diaphragm; a chamber adjacent said first diaphragm and formed on one side by said first diaphragm, said chamber including means for receiving said reference gas; a second continuous diaphragm generally parallel to and spaced from said first diaphragm a predetermined distance; plug means intermediate said first and second diaphragms, said plug means having a first substantially flat face in contact with said first diaphragm and a second substantially flat face in contact with said second diaphragm, the width of said plug means between said first and second faces being substantially the same as said predetermined distance; a valve in contact with said second diaphragm, said valve adapted to open and close in response to movement of said second diaphragm; a second chamber adjacent said second diaphragm and formed in part by said second diaphragm, said second chamber being adapted to receive said controlled gas; biasing means in said second chamber for exerting a force on said plug means tending to move said plug means towards said first chamber thereby opening said valve means; inlet means for passing controlled gas into said second chamber; and exit means for passing controlled gas through said valve means and out of said second chamber; said apparatus further characterized in that the cross sectional area of said first face is smaller than the cross sectional area of said second face.