Pressure Converter/Transmitter

The pressure transmitter uses exhaust gas back-pressure and intake manifold vacuum inputs to determine a control vacuum which it supplies to the EGR valve lower diaphragm. The strength of this control vacuum determines the quantity of exhaust gas recirculation. For example, the exhaust gas back-pressure increases and intake manifold vacuum decreases as the throttle is opened. This will result in a decrease in control vacuum and an increase in the amount of exhaust gas recirculation.

The vacuum inputs to the EGR valve from the pressure transmitter and the electromagnetic switching valve or thermo valve, result in a continuous balance condition between the upper and lower EGR valve diaphragms. This enables the EGR valve to provide a wide range of operating capability and quick response in engine operating conditions.