A two-stage regulator is used when accurate delivery pressure is important. A two-stage regulator reduces the cylinder pressure to a working level in two steps. The cylinder pressure is reduced by the first stage to a preset intermediate level, which is then fed to the inlet of the second stage.

Since the inlet pressure to the second stage is so regulated, the delivery pressure (manually set by means of the adjusting handle) is unaffected by changes in the cylinder pressure. Thus, the two-stage pressure regulator provides precise control of the gas being consumed. A two-stage regulator performs best when it is attached to the cylinder and adjusted to the desired reduced pressure, and then remains in service until the cylinder is ready for changeout. When a gas pressure regulator is operated within the manufacturer’s recommended procedures and is not abused, it provides many years of trouble-free service. Regulators are normally leak checked before they are shipped from the manufacturer.