a pneumatic regulating valve that operates on high - temperature , high - pressure gases . this invention reduces the upstream pressure of a flow of gas , which can be as high as 10 , 000 psia , down to a level usable by downstream control valves , which may require controlled pressure input . the springs and seals of this invention are isolated from the high temperature and pressure of the upstream gas , thus enabling regulation of gas flows of up to 10 , 000 psia and 2 , 500 ° f .