If is original with throttle + measure flow differential pressure transmitter, transmitter is common with three valves or five valves, valves are two for cut, one for balance, five-valve two cut off is the role of both emissions, a balanced
Differential pressure transmitter connection pipe with the "valves", are:
1, in the pipeline from its initial state (empty) to participate in media, sensor pressure suddenly changes on both sides, pressure increase, in order to prevent, should close the sensor valves on either side of a, b, open the bypass valve c;
2, in a medium filled pipe, and after reaching a smooth, balanced, gradually opened the a, b, bring the average pressure sensors on both sides;
3, close valve c, sensor began operating properly;
4, close the order contrary to the situation described above.
In addition, 3 valves also have other effects, such as cleaning pipes after running for some time, local sensors are not affected (pipeline bypassing).