The QB3H is an electronic pressure regulator capable of operating at high pressures (to 500psig/34.47 bar) and high forward and relief flows (to 50scfm/1416slpm). The QB3H consists of two solenoid valves which add or subtract pressure to the pilot of an integral volume boosting regulator. An internal stainless steel pressure sensor measures the high pressure output of the integral volume booster and sends this signal to the onboard controller. This controller then modulates the two solenoid valves to match the integral volume booster's output pressure to the user's requested command signal. All brass body units are oxygen cleaned at the factory.