The main structure of flange valves includes valve body, valve cover, valve stem, sealing surface and connecting flange. Specifically:
Valve body and valve cover: The valve body is the main part of the flange valve, usually made of cast iron, cast steel or stainless steel. The appropriate material is selected according to the corrosiveness and pressure level of the use environment. The valve cover is located above the valve body and is used to close the valve to prevent medium leakage.
Valve stem: The valve stem is a component that connects the handle or actuator to the valve core, and transmits the operating force to rotate or lift the valve core. The valve stem needs to have sufficient strength and wear resistance and corrosion resistance. Some are designed with sealing sleeves to prevent medium leakage.
Sealing surface: The sealing surface is the key part of the valve, ensuring that the valve can prevent medium leakage when it is closed. The sealing surface material is usually made of plastic and other materials with good sealing performance.
Connecting flange: The flange valve is connected to the pipeline through a flange and bolts to ensure the firmness of the connection and easy disassembly.
Structural differences between different types of flange valves
Flanged ball valve: The ball is floating or fixed, and a sealing surface is formed between the ball and the valve seat. The rotation angle of the ball valve is usually 90 degrees, and the opening and closing are achieved by rotating the ball.
Flanged butterfly valve: It is mainly composed of a valve body, a butterfly plate, a valve stem and a sealing structure. The butterfly plate is connected to the actuator through the valve stem and rotates around the axis of the valve stem to cut off and adjust the flow. The sealing structure uses a rubber sealing ring or a composite material to ensure a two-way sealing effect.
Flanged gate valve: The opening and closing part is a gate, and the movement direction of the gate is perpendicular to the direction of the fluid. The gate has two sealing surfaces, usually in a wedge-shaped or parallel form. The gate valve can only be fully opened or fully closed, and the flow cannot be adjusted.