Understanding the various differences between control valves and regulators is very crucial in any automation industry. Each one of these has equal importance and at the same time have few different functions and operate also in different ways.
It is necessary that engineers must be well-informed about both the solutions, so that during the control process systems design, they don’t have any major problems or they waste resources and money.
Understanding the difference
In order to have better understanding of the differences between control valves and regulators we must first look into each of its individual components, in terms of its design.
Any typical control loop will allow control valves to use range of process variables. It will depend upon the kind of variable that needs to be measured for control e.g. level, flow, pressure or temperature.
These process variables are first measured by using certain transmitter or sensor. After that its output is sent to any control system.
Mostly this kind of system is called as DCS which is Distributed Control System. DCS is responsible for making interpretation how any particular valve must respond to any deviation from its set limit value.
After this, the signal is passed back to DCS control, that will decide which of the actuator should open or close the valve for returning back to the set limit as done before.
Operationally, the basic difference between any control valve and Fisher regulator is that any regulator is better defined as a kind of process powered valves that does not need for any external power or air source for its operation.
Typically, any regulator will apply the pressure of process fluid against any diaphragm. Same diaphragm will then reject a compressed spring for achieving forced balance with diaphragm at any given set pressure.
In case there happens to be any change in controlled pressure then the diaphragm will be forced to move. Then this will cause the regulator’s flow area to change that allows either more or less fluid to flow out.
Since such fluid pressure is used for controlling or regulating are also functioning as any pressure control valve.
Another difference is based on the design rating of body pressure of regulator. Any control valve can handle the same amount of pressure on outside of the valve as they usually are on inlet side.
However, any regulator may also have a lower rating of pressure on the side of control pressure of regulator. This is because of fluid pressure which is directly applied on the components of diaphragm casing.
Another difference is speed. As compared to any control valves, the response speed of regulator is faster. Regulators can respond instantly to any changes in control pressure that is occurring. Also, they are much simpler to maintain and also have got no volatile emissions.
Any control valve, however, is available in much larger in size and is in higher pressure class than regulators is.
As mentioned earlier proper understanding of the differences between control valves and regulators is very important in automation industry.