Proportional Valve Electronic Pressure Regulator
Featured Product from Kelly Pneumatics, Inc.
Kelly Pneumatics, Inc. offers a dual proportional valve design, Electronic Precision Pressure Regulator with I/P transducer control circuitry. The proportional pressure regulator is a closed loop control unit that incorporates two proportional valves, a manifold, and control circuitry including a pressure sensor and electronic circuit.
The critical technology of the precision pressure regulator is the dual proportional valve design. One valve controls the inlet and the other the exhaust; both valves proportionally increase or decrease the output pressure, respectively. The incorporation of two proportional valves avoids many problems associated with traditional on/off valve regulators. This is mostly due to the inherent design of the proportional valves that control the pressure regulation. Each proportional valve uses a single armature design, which offers virtually frictionless performance. Outlet flow is acquired by proportionally moving the single valve armature away from the valve inlet orifice. The total travel distance of the valve armature is 0.001 inches. Any small increase or decrease in the armature's distance from the valve orifice will result in variable outlet flow rates.
Traditional electronic pressure regulators typically employ a dual on/off valve design, with both an inlet and exhaust valve: changes in pressure are controlled by cycling the on/off valves to open and close via Pulse Width Modulation, which can be problematic. Problems associated with the Pulse Width Modulation of on/off valves include: a much shorter life of the product due to frequent valve cycling, product noise, control circuitry dead-band, pressure output oscillation, as well as less consistent performance during steady states.
Other pressure regulator units available on the market incorporate an inlet proportional valve to compensate for these performance issues. However, these units typically incorporate a single on/off solenoid exhaust valve to vent excess pressure and compensate for changing flow rates to the system. Typically, this is achieved with rapid valve cycling, so applications with dynamic performance rates will suffer most, as the exhaust valve must continually cycle at a particular hertz to compensate for the dynamic changes in performance.