PISTON 3760635 - Caterpillar

The primary (CAN) and secondary (PWM) mass flow demands are continuously monitored. If either one of the signals is received, the RAPTOR valve will wait for 5 seconds (to ensure a stable signal) and then switch to the available signal. If both the primary and secondary Qgn demand signals are available, the valve will switch to the primary demand (CAN).If a valid flow demand is received, the RAPTOR valve will calculate the area needed by the valve to provide correct flow. This area is calculated using the delta pressure, DP (inlet to outlet pressure differential), the absolute inlet Fuel Gas Pressure (FGP), the Fuel Gas Temperature (FGT), the Qgn (Demand signal), the Gas properties (Sg and K), and the calibration information stored in the valve. The actuator then positions the valve to achieve the calculated area. If the flow demand is zero for longer than 10 seconds, the RAPTOR valve will disable the actuator coil (no power to the coil) so that the valve will consume less power.See chapter 6 (Troubleshooting) for more information on non-normal operation.