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Classification and scope of use of imported regulating valves

The classification of the regulating valve is mainly based on its actuator, and there are electric regulating valves and pneumatic regulating valves. There are also four types of structures, such as single seat, sleeve type, double seat type, and cage type. The main types of regulating valves are divided into three types: three-way type, angle type, high temperature type, low temperature type, bellows type and so on. The functions of the electric control valve and the pneumatic control valve are as follows:
The electric control valve is an industrial field execution instrument consisting of a regulating valve body with different electric actuators. It accepts 4-20 mA or pulse signal from the regulator for closed-loop control to achieve flow, pressure, temperature and liquid level. Automatic control of parameters, and the choice of intelligent electric actuators, digital transmission with DCS, PLC, etc., to form a more intelligent control system. The power supply voltage of the electric control valve is 220V and 380V. The flow characteristics of the electric control valve are equal to percentage, linear and fast. Compared with pneumatic control valves, electric control valves are energy-saving (only consume electricity when working), environmentally friendly (no carbon emissions), quick and easy to install (no complicated pneumatic piping and air pump workstations), and are widely used in electric power. Industrial automation systems such as chemical, metallurgy, environmental protection, water treatment, light industry, and building materials.
The pneumatic regulating valve is divided into a pneumatic diaphragm regulating valve and a pneumatic piston regulating valve. It is a compressed air as a power source, a diaphragm type or a piston type cylinder as an actuator, and is protected by an electric valve positioner, a converter, a solenoid valve, and a protector. The valve and other accessories drive the valve to realize the switch quantity or proportional regulation, and receive the control signals of the industrial automation control system to complete various process parameters such as adjusting the flow, pressure and temperature of the pipeline medium. Pneumatic control valves are characterized by simple control, fast response, and intrinsic safety, without the need for additional explosion-proof measures. The cost of the pneumatic regulating valve is also lower than that of the electric regulating valve. In the fields of chemical industry and petrochemical, the pneumatic regulating valve has the incomparable advantage of the electric regulating valve.
The main features and applications of the regulating valve are as follows:
Single-seat control valves are mainly used in applications where the amount of leakage is small and the pressure difference is small.
The sleeve regulating valve adopts a balanced valve core with large unbalance force, which allows large pressure difference and stable operation.
Cage regulators are especially suitable for applications that allow for small differential pressures and large differential pressures before and after the valve.
The two-seat control valve is especially used in applications where the differential pressure is large and the leakage is not critical.
Three-way regulating valve: The combined flow type is mainly used to mix two fluids into a third fluid; the split type is mainly used to divide one fluid into two fluids.
The angle control valve is especially suitable for high viscosity, fluids containing suspended solids and granular media to avoid coking, sticking and clogging.
The high temperature type regulating valve is suitable for occasions where the flow rate is large, the temperature is high, and the leakage amount is not strict.
The low temperature type regulating valve is suitable for operation below 0 to -250 °C.
Bellows type regulators are suitable for the regulation of extremely literate, flammable, explosive, volatile and rare precious metal media.

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