Assembling these valves and then erecting it, starting it and maintaining it requires large space.

Closing and opening feature is not very prompt.

It provides laminar flow and hence the loss of pressure is minimum.

This design or body is used for the valves that manages the automatic emergency shut off and also for the hand-operated valves. It is best suited to regulate the high temperature and pressure for variety of liquid flow and has an on-off application. Gate valve comprises of flat barrier which is adjusted to effect the area of flow. Furthermore, based on the types of services it offers, it can be classified as:įor ON-OFF Services – Gate, Diaphragm Ball, Plug, Butterfly valves.įor THROTTLING Services – Globe, Diaphragm, Butterfly, Pinchįor NON-REVERSE FLOW – Check valves Gate Valves On the basis of stem movement, valves can be broadly classified as linear or rotary type. Values categorization: It’s advantages and disadvantages Thus, the control valve working principle revolves around the manipulation of the flowing fluids such as water, gas, steam or chemical compounds to ensure minimizing the load disturbance and regulating the process variable to the closest value of the desired set point. This is where the control valve comes into the picture and work to reduce these disturbances. Once the data collected is analyzed, measured, compared and calculated then a controlling element is implemented.

The information collected is then processed by the controllers to decide what should be done to rectify these load disturbances. Each of these control loops experience internal disturbance and these disturbances are measured by sensors and transmitters. These control loops have a set pressure, temperature, flow, level in order to maintain the required operating range. The process plant comprises of numerous control loops in order to deliver consistent quality products. The electric, hydraulic and pneumatic actuators automatically controls the opening and closing of the control valve while the positioners control the closing and opening of these actuators.

In other words, control valve is used to control the flow, pressure, liquid level, and temperature of the system by completely or partially opening or closing it based on the signals received by the controllers. It is also refereed as ‘final control element’ in automatic control terminology. It helps in directly controlling the flow rate and thus helps in regulating the other vital processes quantities such as temperature, liquid level/flow, and pressure. Control valve is used to regulate the fluid flow by changing its size or course as directed by the signal from a controller.

How to set pressure in water cad