49. Open bypass valve and close the inlet and outlet valves for the back flushing filters.
A、
A、Closebypassvalveandopenthevalvesforthebackflushingfilters.;
B、
B、Openbypassvalveandclosethevalvesforthestrainers.;
C、
C、Closebypassvalveandclosethevalvesforthebackflushingfilters.;
D、
D、Openbypassvalveandclosethevalvesforthebackflushingfilters.
发布时间：2025-10-28 10:22:18
