Uses: It is installed on the top of tank body of tank car to seal the tank mouth, which is completely sealed with the outside to ensure the anti-overflow and anti-explosion function of tank car when tilting. When the pressure inside and outside tank changes, the built-in breather valve installed on the large cover can effectively adjust the pressure to ensure the pressure balance inside and outside the tank; when the tank pressure is too high, the built-in breather valve can not meet the discharge requirements, the gas in the tank can overcome the spring pressure on small cover to open the small manhole cover, which will release excessive high pressure quickly to ensure safety. At the same time, the installation port of anti-overflow probe rod, the installation port of oil and gas recovery valve and small oil hole are reserved on the large cover for easy installation.

Structure characteristics: The main bodies of the large and small cover are formed by one-time die casting of 900-ton die casting machine, which has the advantages of good compactness and high strength. Thickness 12 mm, 24 mounting holes.