What is Stroke Checking of Control Valves? All control valves need to be stroked after some time in service. This is due to the fact that the valve is a mechanical mechanism that has physical components. These components must constantly be in excellent functioning condition in order to prevent the valve from failing. Stroking the …
How does self-actuated pressure control valve Work? Describe the types of Self-Operated Control Valves Types of Self Operated Control valves 1. Pressure Reducing Valves: 2. Back Pressure Valves: 3. Bleeding and Venting Valves 4. Condensate & Steam Traps 5. Vacuum Breakers How to Size a Self-Actuated Pressure Regulator? Some other important factors to be considered …
A brief overview of temperature control valve: Temperature control valves (TCV) are known as De-super heaters, Attemperatures, or temperature regulators. They are referred to as common control elements used in the process control industry. Temperature control valves in process industries are an integral part of various applications, such as power generation units, oil and gas …
The control valve with a dead band behaves like there may be some kind of resistance or response between the output of the controller and the actual position of the stem in the valve actuator. When the direction of controller output is changed at any instant. The dead band needs to pass over before the …
Measurement of the dead band in a control valve Read More »
Specification of a control valve begins with a control loop. The control loop in every industrial application includes transmitters to transmit the signal to the controller then to the positioner and finally to the actuator of the control valve. The valve assembly consists of : Positioner to convert electric signal to pneumatic signal. Actuator for …
How to specify control valves for process applications Read More »
In every control system of the process industry, the control valves are the most essential element to control or regulate the fluid flow in a line for a particular process operation. In general, it is referred to as a final control element. In every control loop, the control valve provides the adjustment or actuation of …
In many process and industrial applications, the fundamental requirement is that a control valve must be able to control the flow rate or stop the complete flow of fluid in the fully closed position. In practice, most control valves still allow for the flow of fluid through the passage even when the valve is in …
What is a control valve flashing? When a process fluid has flowed through restriction of the control valve. There is an increase in the velocity of the process fluid. Flashing can be predicted by the Continuity equation The continuity equation states that “For any flow rate the product of fluid density, flow area, and its …
What is the controller action? The controller action is defined as the function of the controller. The controller action determines whether The controller output increases when PV increases above the set point, or The controller output decreases when the PV is increased above the set point. The operator has to select the controller action based …
Working of Direct Acting and Reverse Acting Control Valve Loop Read More »
Cavitation is a phenomenon that occurs in a control valve during sizing control valves for liquid flow applications. Cavitation in the valve occurs in fluid flow systems where the local static pressures are below the fluid’s vapor pressure. According to the Bernoulli equation the cavitation in the valve occurs when a fluid accelerates in a control valve …