Timed purging device for boiler air and smoke system instrument pipeline

The utility model discloses a timed purging device for an instrument pipeline of a boiler air and smoke system. The timed purging device comprises two air volume differential pressure sampling pipes, the end part of the air volume differential pressure sampling pipe is communicated with the first air inlet of the corresponding switching valve; the end part of the compressed air pipeline is respectively communicated with the second air inlets of the two switching valves through pipelines, and an on-off valve is mounted on the compressed air pipeline; and air outlets of the two switching valves are communicated with the air volume differential pressure transmitter. The air volume measuring device has the advantages that the switching valve is controlled by the time control switch to switch between compressed air purging and sampling measurement of the sampling pipe, so that timed automatic purging is achieved, manual intervention is not needed, long-time uninterrupted work can be achieved, purging is conducted