Gas pressure regulators serve a fundamental purpose to maintain a consistent outlet pressure despite fluctuations in the inlet pressure or changes in gas demand. They achieve this by automatically adjusting the flow of gas based on the upstream pressure and downstream requirements. When gas flows through the regulator, it passes into a sensing mechanism that detects the current pressure. If the pressure exceeds the setpoint, the regulator modulates the gas flow by using a diaphragm or spring mechanism to open or close a valve, thus preventing overpressure in the downstream system. This process is critical to prevent equipment damage, explosions, or leaks that can occur if gas is supplied at an uncontrolled and excessively high pressure.