Pressure reducing regulator for oxygen service

In a pressure regulator for regulating the flow of oxygen supplied to the regulator from a source of oxygen at a high inlet gas pressure comprising:

• a regulator body having an inlet opening adapted to be connected to said source of high pressure oxygen;
• an oulet opening for discharging the oxygen at a controlled reduced pressure;
• a valve chamber having an upstream and downstream end relative to said flow of the oxygen;
• a valve assembly disposed within the valve chamber and including a slidable valve member containing a valve seat disposed at the downstream end of the valve chamber, a valve stem and a nozzle;
• a control chamber located in the nozzle;
• a bonnet having a bonnet chamber;
• and a diaphragm assembly having a flexible diaphragm for forming a diaphragm chamber between the bonnet chamber and the nozzle and bleed passages for controllably coupling the diaphragm chamber to the control chamber the improvement comprising:
• a disk like metallic shield suspended from the diaphragm in the diaphragm chamber and in close proximity to the diaphragm, said metallic shield being very thin and flexible so as not to disturb the regulating function of the regulator and having a relatively large diameter covering a substantial proportion of the diaphragm in the diaphragm chamber so as to isolate and protect the diaphragm from any hot gases or combustibles issuing from the bleed passages in response to an ignition in the regulator.