3. Inspection of pneumatic ball valve after installation
(1) Operate the driver to open and close the pneumatic ball valve for several times, which should be flexible without stagnation, to verify that it works normally.
(2) The design of connecting pipeline requires that the sealing performance of the flange joint surface between the pipeline and the spherical jaw should be checked.

3. How are measurements classified? What are the characteristics? Measurement credits are divided into scientific measurement, engineering measurement and legal measurement, which respectively represent the basic aspects, application aspects and public welfare aspects of measurement. Measurement is characterized by accuracy, consistency, traceability and legislation.