Valve Seals: Regulating Valves And Seals
Dec 30, 2021
Valve seals: regulating valves and seals
The regulating valve, also known as the control valve, in the industrial automation process control domain, is the total control element that changes the process parameters such as medium flow, pressure, temperature, liquid level, etc. by means of power operation by accepting the control signal output by the regulating control unit.
Control valves are used to adjust process parameters such as medium flow, pressure, temperature, liquid level, etc. in the field of industrial automation process control. According to the control signal in the automation system, the valve switch is automatically adjusted, so as to realize the adjustment of medium flow, pressure, temperature and liquid level. The regulating valve is usually composed of an electric actuator or a pneumatic actuator and a valve body.There are mainly two types of straight-through single-seat type and straight-through double-seat type. The latter has the characteristics of large flow capacity, small unbalanced force and stable operation, so it is usually especially suitable for occasions with large flow, high pressure drop and less leakage.Rotary motion valves mainly include: V-type electric regulating ball valve, electric battlement valve, ventilation control valve, eccentric battlement valve, etc. The flow capacity Cv value is the main parameter for the selection of the control valve.
The flow capacity of the control valve is defined as: when the control valve (control valve seal) is fully opened, the pressure difference between the two ends of the valve is 0.1MPa, and the fluid density is 1g/cm3, the flow rate of the flow path control valve per hour is called. is the flow capacity, also known as the flow coefficient, expressed in Cv, the unit is t/h, and the C value of the liquid is calculated as follows. Whether these controls are energy exchanges, pressure reductions, or simple vessel filling, certain final control elements are required. The final control element can be thought of as the "physical force" of the automatic control. Between the low energy of the regulator and the functions required to perform flow fluid control, the final control element accomplishes the necessary power amplification.
