Tag: process control
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Valve Positioners: Function & Types
Basic Features of a Positioner Pneumatically operated valves depend on a positioner to take an input signal from the process controller and convert it to valve travel. In other words, a positioner is a motion control device made to actively … Read more
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Directional Control Valves: Function & Principle of Operation
Directional control valves are used to regulate the flow rate of hydraulic fluid; they are also utilized in pneumatic systems for flow control. Directional control valve works by regulating the movement of the piston in the cylinder. It admits pressurized … Read more
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Instrument Manifolds: Function & Types
An instrument manifold also referred to as a valve manifold includes manual valves to isolate and equalize pressure from the process to the transmitter (in this case the DP transmitter) or to isolate a gauge or absolute pressure transmitter for … Read more
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Pressure Regulators: Function & Types
The main function of any gas pressure regulator is to match the flow of gas through the regulator to the demand for gas placed upon the system while maintaining the system pressure within certain acceptable limits. Generally, regulators are simpler … Read more
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PLC Instruction Set
An Overview of PLC Instructions Types There are various types of instructions that are available in a PLC. The instruction set will vary depending on the brand and type of processor you are working with. For example, the classic Allen-Bradley … Read more
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Demand Mode vs. Continuous Mode Safety Function
Demand Mode Safety Function Demand mode safety function is where a specified action is taken in response to process conditions or other demands. In the event of a dangerous failure of the SIF, a potential hazard only occurs in … Read more
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Input & Output Modules of a PLC – Types & Applications
The input/output modules act as the signal interface between the monitoring sensors and actuators, and the controller. Additional they provide electrical isolation, if needed, to convert the input signals into an electronic format appropriate for evaluation by the … Read more
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What is the Safety Instrumented Function (SIF)?
The safety instrumented function (SIF) is used to monitor a selected process parameter and takes an executive action to make the process safe, if certain limits are exceeded. An illustration of safety instrumented function in a process plant is shown … Read more
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How HAZOP Technique is used to identify Hazards in a Process
In functional safety, hazards are events which have the potential to cause harm such as personal injury, damage to the environment or the business. Hazards in the process industry might include: the pressure of liquid in a vessel (high pressure … Read more