The distinction between regulating valve and control valve

Of control valve and control valve in our country now is no clear distinction, basic tend to control valve and control valve generally call together, more will become a regulating valve with actuator valves are, and the concept of control valve has not yet deeply rooted in the hearts of the people, see those doing the control valve on the web site, is called the control valve regulating valve.I think it is necessary to clarify some of the concepts here.

The definition of control valve should be: process control industry is the most commonly used terminal control element, is the control valve.A control valve regulates the flow of a fluid, such as a gas, steam, water, or chemical mixture, to compensate for load disturbances and keep the controlled process variable as close to the desired set point as possible.Sensor will pressure, temperature, flow and other signals feedback to the regulator, regulator will measure the signal and set value for comparison, and then according to the results of the operation output control signal to the control valve, the control valve to adjust the opening of the valve, so as to achieve automatic adjustment of temperature, pressure, flow and other parameters.According to this definition, the valve must be combined with sensors, controllers (PLC DCS or pure regulator) to form a control loop (whether single loop or multiple loop) to realize the control of process variables, to be called a control valve.Therefore, all pneumatic, electric and hydraulic valves equipped with execution results should be called control valves, including solenoid valves, because they can form a control loop with the control system for automatic control.The principle of control is the same regardless of whether they receive an enable or a proportional signal.All manual valves are not control valves.Some valve manufacturers have a name for a self - control valve, which should be defined the same way as a control valve.

The regulator, which is essentially a throttle, is intended to produce a pressure drop and reduce flow, so it can have a seat significantly smaller in diameter than the valve size.Throttles are designed to produce pressure reductions in straight lines of pressure, flow, and temperature, while switching valves are designed to allow straight lines through the fluid without producing significant pressure drops.Such as o-type ball valve, butterfly valve, pipe clip valve, their group flow is very small, medium through the pressure drop is very small, so who and switch control, not suitable for throttling control.Throttle valves need to be designed according to the process requirements of the appropriate amount of flow characteristics and valve core, seat diameter, the switch valve is not required.Throttle valve with an actuator, is the electric, gas or hydraulic regulator.So in a narrow sense, the regulating valve is only limited to throttle valve such as single-seat valve, two-seat valve, sleeve valve, Angle valve, three-way valve, v-type ball valve and other limited (so in the industry and manual regulating valve said)

It can be said that all regulating valves are control valves, but control valves may not be regulating valves.As for the self-regulating valve, it should not be classified as a control valve class, because whether it is self-regulating pressure valve, or temperature, flow control valve, are relying on the power of the medium itself to drive the valve, control variables have to rely on manual Settings, they can not and control system control loop.They should be with the relief valve, trap, pressure relief valve, hydraulic control valve and other automatic valve class

Personal view, if you want to simplify the classification of valves, as divided into switch valves, throttle valves, automatic valves three categories.