The Threaded flange is normally referred to as the "high hub" Flange

　　The Threaded flange is normally referred to as the "high hub" Flange. It is designed to transfer stresses to the pipe, thereby reducing high stress concentrations at the base of the Threaded Flange. The Threaded Flange is the best designed Threaded Flange of those currently available because of its inherent structural value. It is expensive because of the design.

　　High Pressure Forged Threaded Flange have been formed products, the diameter is usually 600mm. The manhole center is 750mm from the floor. Easy to staff in the installation, cleaning, maintenance, access to the tank and ventilation. The manhole of the non-metallic oil tank is arranged on the top of the tank, and the manhole of the metal oil tank is arranged on the bottom circle plate of the tank wall. Most of the diameter of 600mm hole, the center distance from the floor 750mm, for tank cleaning or maintenance personnel out of the tank, also known as the door. Maintenance Clean up the tank at all times using the manhole for lighting and ventilation. When the capacity of the vertical oil tank is 5000 mm or less, there are 1 to 2 manholes, and two orifices of 5000 mm or more are provided.