Exhaust pneumatic valve and drain the function of the pneumatic valve, in which case set

（ ） Exhaust bulge part of the pneumatic valve installed in the pipeline, the pipeline and put into operation or after repair drainage systems, pneumatic valve discharge pipe by the air. To rule out release of gas from water at ordinary times, in order to avoid air accumulated in the pipe, so that to reduce water area and increase the loss of the pipeline. Long water pipe with general relief, laying on high exhaust pneumatic valve.
（ ） In the bottom of pipeline shall be installed pneumatic valve, drain it and drain connections, to eliminate sediment from water pipes, and repairing emptying the water in the tube. To accelerate the drainage, can according to need to install the recent tube and inlet pneumatic valve at the same time.