Pressure regulators work by automatically adjusting the flow of gas based on the demand from users. They can sense changes in both inlet pressure (the pressure coming into the regulator) and outlet pressure (the pressure going out to the consumers). When the outlet pressure exceeds a preset level, the regulator responds by restricting gas flow, thereby maintaining consistent delivery pressure. Conversely, if the outlet pressure drops, the regulator allows more gas to flow, ensuring that consumers receive the necessary amount of gas for their needs.