Direct operated regulators – They are the simplest form of regulators (Fig. 1). They normally operate at lower set pressures, below 0,07 bar (1 psi) and can have greater accuracy. At higher pressures, up to 35 bar (500 psi), they can have 10-20% accuracy levels.
Pilot operated regulators – These regulators are ideal for applications with large variation in flow rates, fluctuations in inlet pressure, or decreasing inlet pressure conditions that normally occur with gas supplied in cylinders or small storage tanks. It provides precise pressure control.