Explosion-proof fire breathing manhole is installed on top of the tank safety emergency ventilation device, usually used with mechanical breather valve and flame damper, which can avoid the outside causes sharp overpressure or vacuum in tank and tank damage and accidents, and can have the effect of fire safety, is to protect the safety of tank device, particularly suitable for storing material to seal the vault atmospheric tank.

When the fire-retarded breathing valve works normally, the emergency pressure relief manhole is basically kept sealed and the storage tank is under normal pressure. When the normal work of the breathing valve is not satisfied with the sudden overpressure of the storage tank caused by unexpected reasons, the pressure relief cover of the manhole is opened actively for pressing pressure relief to keep the pressure in the tank normal; When the pressure in the tank is sharply reduced or ultra-vacuum, the suction valve will open to sharply inhale the atmosphere and maintain the normal pressure in the tank. When the air is filled with sparks and flames, the fire retardant layer ACTS as the "wall effect" to prevent the passage of the flame, so as to protect the safety of the storage tank.

The manholes are divided into emergency pressure relief manholes, fire-proof breathing manholes, tank roof manholes, tank wall manholes and cored manholes.

Pressure relief manhole is a safety emergency ventilation device installed in petrochemical equipment and storage tanks. It is generally used in combination with the breathing valve installed on the roof of the tank to maintain the normal pressure in the tank, which can prevent the tank from being damaged due to sudden overpressure or vacuum caused by unexpected reasons. It has advantages of constant pressure discharge, constant pressure suction, flexible closure, compact structure, good sealing performance, safety and reliability.

Pressure relief manhole is developed by our company according to the market demand and referring to the advanced technical data at home and abroad. It is a safety emergency ventilation device installed on the storage tank of petroleum, chemical and other materials. It is usually used in combination with the breathing valve, which can avoid the occurrence of damage to the storage tank caused by sudden overpressure or vacuum in the tank caused by unexpected reasons. It can also play a safety role. It is the ideal equipment to protect the safety of storage tanks in China. Product selection of all-weather sealing structure, spring to regulate the suction valve disc and pressure relief valve open and close, in a word, the product has fixed pressure emissions, flexible, compact structure, good sealing function, safe and reliable and other advantages.

The flame-proof breathing manhole replaces the plane sealing structure of the cutting edge with the all-weather sealing structure, which significantly improves the sealing degree, and replaces the spring adjustment with the weight adjustment of the suction disc to control the closing of the suction disc, effectively improving the flexibility and reliability of the opening and closing of the suction disc, thus achieving the control of the suction pressure.

When the fire-proof breathing valve works normally, the fire-proof breathing manhole is kept sealed and the storage tank is under normal pressure. When the normal work of the breathing valve fails to meet the sudden overpressure of the storage tank caused by unexpected reasons, the pressure relief cover of the breathing manhole will automatically open and perform emergency pressure relief to keep the pressure in the tank normal. When the pressure in the tank is sharply reduced or ultra-vacuum, the suction valve will open to sharply inhale the atmosphere and maintain the normal pressure in the tank. When the air is filled with sparks and flames, the flame retardant layer ACTS as the "wall effect" to prevent the passage of the flame, so as to protect the safety of the storage tank.

The manhole device is installed on the * lower body ring of the oil tank. Two flange contact surface must ensure that its straightness, no wave twist phenomenon. Reinforcing plates and flanges shall be cut rather than spliced on the whole plate as far as possible. Flange and cover plate processing seal ring, in the construction should pay special attention to maintenance. Seal with 3mm thick asbestos rubber gasket, not allowed to crack. When tightening the bolts on the manhole cover plate of the device, it shall be diagonal and forced to prevent deformation of the manhole cover. It has the advantages of constant pressure heat emission, constant pressure suction, reasonable structure, good sealing performance, safety and reliability, etc.