Valve actuators provide force to move control valve trim. For precise positioning of a control valve, there…
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The purpose of a control valve actuator is to provide the motive force to operate a valve mechanism. Both…
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A different strategy for controlling the flow of fluid is to insert a rotary element into the flow path.…
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Valves can experience a number of problems, most of them either preventable or repairable. These problems can…
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Diagnostic ability is arguably the most difficult skill to develop within a student, and also the most…
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Labwork is an essential part of any science-based curriculum. Here, much improvement may be made over the…
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Tube, like pipe, is a hollow structure designed to provide an enclosed pathway for fluids to flow. In the case…
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One of the most common, and most useful, pressure measuring instruments in industry is the differential…
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When a high-energy photon strikes an atom, it may eject one of the lower-level electrons from its shell,…
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A machine in the broad sense of the word is any device designed to translate some form of energy into useful…
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Some problem-solving techniques are unique to quantitative problems, involving mathematical calculations. In…
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Displacer level instruments exploit Archimedes’ Principle to detect liquid level by continuously…
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A damper (otherwise known as a louvre) is a multi-element flow control device generally used to throttle large…
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Control valves are supposed to deliver reliable, repeatable control of process fluid flow rate over a wide…
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The reason why a pneumatic control valve’s stem position corresponds linearly to the amount of air…
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To show a practical process example, let’s examine three diagrams for a compressor control system,…
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The final step in treating wastewater before releasing it into the natural environment is to kill any harmful…
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Some analyzers measure the composition of a process stream by directly immersing the sensing element in that…
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So far we have just looked at instruments that sense, control, and influence process variables. Transmitters,…
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An on/off valve is the fluid equivalent of an electrical switch: a device that either allows unimpeded flow or…
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This animation shows the basic operation of a gas chromatograph, showing the separation of different molecular…
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As discussed at the beginning of this chapter, instrumentation safety may be broadly divided into two…
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Non-dispersive analysis, while newer in discovery than dispersive analysis (Isaac Newton’s 17th-century…
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One very convenient feature of waves is that their properties are universal. Waves of water in the ocean,…
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Once while working as an instrument technician in an aluminum foundry, a mechanic asked me what it was that I…
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Valves can experience a number of problems, most of them either preventable or repairable. These problems can…
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Layer 1 of the OSI Reference Model is where we define the “physical” elements of a digital data…
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Imagine a liquid-level control system for a vessel, where the position of a level-sensing float sets the…
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It is possible to convey electrical power and communicate analog information over the same two wires using 4…
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Fieldbus devices require far more attention in their initial setup and commissioning than their analog…
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Any physical location in an industrial facility harboring the potential of explosion due to the presence of…
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Control valves are supposed to deliver reliable, repeatable control of process fluid flow rate over a wide…
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“As to methods there may be a million and then some, but principles are few. The man who grasps…
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Many years ago, when I was first learning about electricity, I happened to discover a length of coaxial…
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These fortifications focus on human behavior rather than system design or component selection. In some ways…
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A fundamental principle in instrumentation system troubleshooting is that every instrument has at least one…
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A sliding-stem valve body is one where the moving parts slide with a linear motion. Some examples of…
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Those familiar with industrial instrumentation will find much within the electric power industry remarkably…
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A number of different sensors used in instrumentation generate DC voltage signals proportional to the process…
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A Safety Instrumented Function, or SIF, is one or more components designed to execute a specific…
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Measuring the flow rate of liquid through an open channel is not unlike measuring the flow rate of a liquid…
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The purpose of a control valve actuator is to provide the motive force to operate a valve mechanism. Both…
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Perhaps the simplest form of solid or liquid level measurement is with a float: a device that rides on the…
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The three “elementary” particles of matter comprising all atoms are electrons, protons, and…
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All masses require force to accelerate (we can also think of this in terms of the mass generating a reaction…
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The disadvantages of pneumatic instruments are painfully evident to anyone familiar with both pneumatic and…
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“Feedforward” is a rather under-used control strategy capable of managing a great many types of…
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As we have seen, feedforward control is a way to improve the stability of a feedback control system in the…
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PID control can be a confusing concept to understand. Here, a brief summary of each term within PID (P. I, and…
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A control strategy similar to ratio control is relation control. This is similar to ratio control in that a…
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AC induction motors are based on the principle of a rotating magnetic field produced by a set of stationary…
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As discussed at the beginning of this chapter, instrumentation safety may be broadly divided into two…
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A whole class of problem-solving techniques focuses on altering the given problem into a simpler form that is…
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A very common method for directly controlling low flow rates of fluids is to use a device known as a metering…
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In some process applications, it is important that the control valve be able to completely stop fluid flow…
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Coy, John J. et. al. (December 2012) Sampled graphic illustrations from his NASA Reference Publication…
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Abdelaziz, Ahmed (June 2014) Identified numerous typographical errors throughout the book, mostly repeated…
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The next level of detail is the Process and Instrument Diagram, or P&ID. Here, we see a “zooming…
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A machine in the broad sense of the word is any device designed to translate some form of energy into useful…
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