Maintenance and maintenance of breathing valve once a month and twice a month in winter.Its method: first open the valve cover slightly, take out the vacuum and pressure valve discs, check the seal between the valve disc and valve disc, the guide rod and guide rod sleeve of the valve disc for oil and dirt. If oil and dirt occur, clean them, then put them back in place, pull them up and down several times to check whether the opening is flexible and reliable.If everything is OK, tighten the bonnet again.During maintenance and maintenance, if abnormal phenomena such as scratches and wear are found on valve discs, they should be replaced immediately or contacted with the supplier so as to be solved in time.