Pressure regulation applications that require sensitive, high-resolution performance have found success with the Proportion-Air QPV series electro-pneumatic proportional pressure regulator.
The QPV line boasts accuracy of up to ±0.2% and resolution of ±0.005%, regulating pressures up to 150 psig or equivalent. Calibration of ranges as low as 0-2 inches of water column are possible. These devices will accommodate flow rates up to 1.2 scfm.
Using a variable orifice valve eliminates the digital steps of traditional ON/OFF solenoids: The field adjustable hysteresis potentiometer allows users to virtually eliminate the deadband of the control circuit, resulting in superior system resolution.
QPV units have two valves and a sensor. In the QPV1 model, a single closed loop device, the internal pressure sensor monitors the output pressure for closed loop control and provides a monitor signal representing active pressure. The analog monitor signal is constantly compared against the command signal to achieve a desired set pressure. In the QPV2 double-loop, or two-loop, option, the unit pilots a volume booster to achieve more flow. The internal sensor and an external feedback device, usually a transducer, ensures that the entire assembly has high accuracy. Both single and double loop units can pilot volume boosters for higher flow applications.
This versatile unit can be modified in numerous ways to meet the most demanding applications. Options include customizable pressure ranges, manifold materials, command and monitor signals and more. Nearly any pressure unit of measure can be specified, including psi, bar and inches of water column, among many others. Many analog command inputs are available, including standard 4-20 mA and 0-10 VDC, as well as serial and specialty options.
Those looking for a device that uses less space with the same great specs can also explore the manifold, DIN rail and panel-mountable MPV option. A single valve option, the SPV, is perfect for constant flow conditions where the media is consumed downstream.