The function of the manipulating device is to influence the process variable. Its main purpose is to regulate a mass or energy flow. Mass flows can be either in gaseous or liquid state e.g. steam, natural gas, fuel oil, etc.… Read more
Category: Process Plants Instrumentation
We cover real requirements for actual process plants as well as some of the techniques employed as solutions to control them.
The Parts and Functions of a Valve
A valve is a mechanical device that controls the flow of fluid and pressure within a system or process. A valve controls system or process fluid flow and pressure by performing any of the following functions:
- Stopping and starting the
Steam-heated Reboiler Control System
When steam-heated reboilers are used in distillation columns and the heating medium is steam, a flow control loop for the steam will typically be incorporated. The control valve can then be placed either in the steam or condensate line. Steam … Read more
Installation Considerations of an Orifice Plate Flow Sensor
If a constriction is placed in a pipe as shown in figure 1 below, the flow must be higher through the restriction to maintain mass flow at all points.
Since the … Read more
Furnace Control System for a Rapidly Changing Demand
Let’s consider the figure below:
In the system above, the output of temperature controller TC represents the process demand, and this signal is applied as one of the inputs, each to a … Read more
Industrial Process Temperature Control System
Let’s consider the industrial process control system shown below:
The requirement is to control the temperature ϴ in the tank. The voltage r, obtained from a potentiometer, is calibrated in terms of the … Read more
How to Perform Mass flow Measurements with DP sensors
Let’s assume we are measuring flow by differential-creating primary device for example an orifice plate and a DP cell as illustrated in Figure 1 below:
The differential head across the primary device is corrected … Read more
Key factors to consider when selecting flowmeters
Selecting the right flow measuring instrument for a given flow application can be a challenging task given the numerous measurement techniques available. In this article, we look at some of the key pointers that can help you in the decision … Read more
Instrumentation and Controls for a Steam Desuperheater
A steam generator is an item of plant equipment that is found in almost every manufacturing site, and its output of steam has many critical uses in a variety of production processes.
Steam has been assigned a measurement quality and … Read more
The Instrumentation for Furnace Control
The figure below shows a typical basic furnace used to raise the temperature of a heat-transfer medium that is used on other equipment in a plant process.
From the figure above, the temperature of the … Read more