Globe Control Valve – an Overview

In industry we need to have control over different parameters of the process like temperature, pressure, level and others depending on the process itself.

To achieve this we would need a controller, it can be a DCS or PLC, sensors and transmitters to send data over to controller, and finally we need a device to carry out the controller’s commands which is usually called as “ Final Control Element”.

Control valve is the most common final control element used in industry today. A control valve is a power operated device used to regulate the flow of fluids. It can be gas, oil, water and also steam.

In this article, we are going to talk specifically about globe valve, why globe valve used as a control valve. Other type of valves will be explained in the next article.

There are several points of consideration why we used globe valve over another type of valve as below:

  1. Linear valve characteristic. In general, globe valve offering more precise control due to their valve characteristic. In the table shown that they have linear flow curve.
  2. High Cycle application. It’s suitable for high cycle applications where the valve needs to be constantly adjusted to maintain certain parameter or known as set point.
  3. The design of seat and plug. There is no contact between the plug and which except the complete closed position to reduce friction.
  4. Cavitation. If cavitation occurs globe valve will be a better solution as a globe valve’s flow path create a higher vena contracta which making the chances of cavitation is lower.
  5. Maintenance. Globe valves need a less frequent seat replacement due to the design of seat and pug. It lacks of constant with the plug.

Additional note on globe valve, it’s not typically used where a bubble tight shut off is required. When a class VI seat leakage required we should consider other type like butterfly of V port valve. It can only be used when class V or class IV seat leakage class is acceptable.

I guess that’s all for today’s topic. See you in next article.