Valve is an important control component in fluid transportation systems. It is used to open and close pipelines, control flow direction, and adjust and control parameters (such as temperature, pressure, and flow rate) of the transported medium. According to their functions, valves can be divided into shut-off valves, check valves, control valves, and others. The following are some common types of valves and their working principles.
Gate Valve: The opening and closing part of a gate valve is the gate. The movement direction of the gate is perpendicular to the fluid direction. Gate valves can only be fully opened or fully closed and cannot be used for adjustment and throttling. Gate valves are sealed by the contact between the valve seat and the gate. Usually, metal materials are surfacing welded on the sealing surface to increase wear resistance.
Globe Valve: Globe valves rely on the pressure of the valve stem to make the sealing surface of the valve disc closely fit with the sealing surface of the valve seat to block the flow of the medium. Globe valves are suitable for on/off and throttling applications. Two-way globe valves are used for precise flow control, and three-way globe valves are used to mix media from two inlets.
Ball Valve: The opening and closing part of a ball valve is a ball. The ball rotates around the axis of the valve stem. Ball valves are easy to operate, have a small volume, can be made with a large diameter, have reliable sealing, a simple structure, and are convenient for maintenance.
Butterfly Valve: The opening and closing part of a butterfly valve is a disc. It rotates around the valve shaft to achieve opening and closing. Butterfly valves have the characteristics of being lightweight, having a simple structure, opening and closing quickly, and having low fluid resistance. They are suitable for occasions that require frequent operation and good adjustability.
Check Valve: Check valves are used to prevent the backflow of the medium. When the medium flows in the forward direction, the valve disc opens; when the medium flows in the reverse direction, the valve disc closes to block the backflow of the medium.
Control Valve: Control valves are used to adjust the pressure or flow rate of the medium. Pressure reducing valves reduce the inlet pressure to a required outlet pressure through adjustment and rely on the energy of the medium itself to automatically maintain the outlet pressure stable.
Solenoid Valve: Solenoid valves are based on magnetic force or coils. When energized, the solenoid valve coil generates electromagnetic force, lifts the closing key to open the valve; when de-energized, the electromagnetic force disappears, and the closing key presses on the valve seat to close the valve.