Gas pressure regulators operate based on a simple principle they adjust their opening size to control the flow of gas. The valve consists of a diaphragm that responds to changes in pressure. When the downstream pressure exceeds the set limit, the diaphragm moves upward, creating a larger opening that allows more gas to flow and thus reducing the pressure. Conversely, if the downstream pressure falls too low, the diaphragm moves down, restricting gas flow and increasing pressure.