You may not need to change your flow meter to change the line size but you’ll definitely need to scale it out to the new process conditions. After you scale out, if the pressure drop falls below your meter’s threshold, then you should shop for a new meter.
To check the operation of your flow meter, use another flow measurement device, for example, a clamp-on ultrasonic flow meter. Attach the second flow meter next to the inline electromagnetic flow meter you want to check and compare the values.
To know more about electromagnetic flow meters, please ask our engineers!