Description
The ultrasonic pulse is fired both with and against the flow, and the difference in flight time between the two directions is monitored using a large-bore, line-of-sight flowmeter. The timing difference indicates the fluid’s speed, allowing the flow rate to be precisely determined. As with the PULSE LF low-flow ultrasonic CIMV, a secondary flow measurement system is incorporated as standard; it consists of two pressure sensors across the throttling valve and a rotary variable differential transformer (RVDT) to provide valve position. Using system-level processing, the data may subsequently be translated to flow rates. To offer an erosion-resistant throttling element, the PULSE HF CIMV employs field-proven multiple orifice valve (MOV) choke trim technology. Two sintered and hot isostatic pressed (HIP) tungsten carbide discs, one stationary and the other moved by a stepper motor through a gear train, make up the MOV trim.
