A device either adjustable or non-adjustable for controlling and maintaining a uniform outlet gas pressure. Spring Type, Adjustable - A regulator in which the regulating force acting upon the diaphragm is derived principally from a spring, the loading of which is adjustable. Spring Type, Nonadjustable - A regulator in which the regulating force acting upon the diaphragm is derived principally from a spring, the loading of which is not adjustable. Either of the above types may be further classified as follows: Main Burner Load Application - A regulator capable of controlling the flow of gas to main burners only. In such applications, the pilot is taken off upstream from the regulator. Main Burner and Pilot Load Application - A regulator capable of controlling the flow of gas to main and pilot burners. In such applications the pilot is taken off downstream from the regulator valve.