Functional accessories such as breathing valve and oil gas recovery valve can be installed on the manhole cover to ensure the safety of the tanker in case of emergency.

Features: 

1. The pressure plate of the emergency exhaust valve is pressed eccentrically, which can avoid accidents caused by the automatic opening of the pressure plate when the tank car is accidentally overpressurized . 2. The exhaust valve equipped with loaded spring has the function of automatic opening, which conforms to the international tank truck transportation standard NTTC DOT406 . 3. It can be used for top loading and unloading of oil .