P&ID Symbols

Below are common symbols normally used in a P&ID, according to ISO 10628 and ISO 14617. Symbols of Instruments used in P&ID Pipe Thermally insulated pipe Jacketed pipe Cooled or heated pipe Jacketed mixing vessel (autoclave) Half pipe mixing vessel Pressurized horizontal vessel Pressurized vertical vessel Pump Vacuum pump or compressor Bag Gas bottle Fan Axial fan Radial fan Dryer Packed column Tray column Furnace Cooling tower Heat exchanger Heat exchanger Cooler Plate & frame heat exchanger Double pipe heat exchanger Fixed straight tubes heat exchanger U shaped tubes heat exchanger Spiral heat exchanger Covered gas vent Curved gas vent (Air) filter Funnel […]

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P&ID Identification and Reference Designation

  Letter Column 1 (Measured value) Column 2(Modifier) Column 3 (Readout/passive function) Column 4 (Output/active function) Column 5 (Function modifier) A Analysis Alarm B Burner, combustion User choice User choice User choice C User’s choice (usually conductivity) Control Close D User’s choice (usually density) Difference Deviation E Voltage Sensor F Flow rate Ratio G User’s choice (usually gaging/gauging) Gas Glass/gauge/viewing H Hand High I Current Indicate J Power Scan K Time, time schedule Time rate of change Control station L Level Light Low M User’s choice Middle / intermediate N User’s choice (usually torque) User choice User choice User choice […]

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P&ID : Piping and Instrumentation Diagram

Piping and Instrumentation Diagrams or simply P&IDs are the schematics used in the field of instrumentation and process control. The P&ID is used by technicians, engineers, and operators to immediately identify an instrument and understand the process and how the instruments are inter connected. The P&ID will use symbols and circles to represent each instrument and how they are inter-connected in the process. Example: “Tag  numbers” composed of letters and numbers are placed within or near the instrument to identify the type and function of the device. The first letter is used to designate the measured variable. The succeeding letter(s) are […]

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Fluid Power Symbols

Fluid power is the use of fluids under pressure to generate, control, and transmit power. Fluid power is subdivided into hydraulics using a liquid such as mineral oil or water, and pneumatics using a gas such as air or other gases. (Wikipedia) Below is the most common Fluid power symbols that is accredited by the American National Standards Institute (ANSI) for use on fluid power circuit drawings.

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What is Calibration?

Whats is Calibration? There are too many definitions of calibration and some are a lot more complicated than the process itself. One simplest definition is that, Calibration is: The process of comparing an instruments’s accuracy to known standards and adjusting it to meet those standards. Calibration of an instrument is checked at several points throughout its calibration range. The calibration range is the region between limits within which a quantity is measured. received or transmitted. The limits are defined by zero and span values specific to that instrument. Why do we need to calibrate? New instruments are calibrated to make […]

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What is an Actuator?

An actuator is a type of instrument that is responsible for moving or controlling a mechanism or system. It is operated by a source of energy, It can be controlled mechanically, by  electric current, hydraulic fluid pressure, or pneumatic pressure, and converts that energy into motion. In my research, I found out that there are 5 types of actuators and these are the following. Mechanical Actuators In mechanical actuators normally a rotary motion is converted into linear motion to perform an operation. Such actuator normally involves gears, rails, pulley, chain etc to operate. Basic example of mechanical actuator is chain block hoisting weight […]

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