Understanding Process Symbols Quiz

Understanding Process Symbols

• Electronic signal: A dashed line
• Pneumatic signal: A line with angled lines at regular intervals, resembling train tracks
• Digital signal: A dash, a circle, and another dash
• Current to pneumatic transducer: A dashed line connecting to a solid line with angled lines at regular intervals, resembling train tracks
• Check valve: A vertical line with a diagonal arrow, followed by another vertical line.
• Orifice plate: Three vertical lines with a smaller vertical line in the middle.
• Block valve: A bow tie with a “T” on top.
• Control valve: A bow tie with an umbrella on top.
• Motor operated valve: A bow tie with a rectangle containing the letter “M” in the center.
• Pump (show suction & discharge): A suction line going through the middle of the pump and a discharge line at the top.
• Exchanger (tube side): A line going through a tube with zigzag lines.
• Exchanger (shell side): A line pointing towards and out of the tube but not passing through it.

Instrumentation Symbols

• FIC: Flow indicator controller
• TE: Temperature element
• TAL: Temperature alarm low
• PI: Pressure indicator
• LG: Level gauge
• d/p: Differential pressure
• FCV: Flow control valve
• LALL: Level alarm low low

Process Flow Diagrams

• A block flow diagram shows the flow scheme in a sequential block form.
• A process flow diagram (P&ID) pictorially indicates the general flow of the process using symbols and major process equipment, but doesn’t show minor details like instrumentation control loops.
• A pipe and instrumentation diagram shows the interconnection of process equipment and the instrumentation used to control the process.
• Instrument identification uses letters and numbers to uniquely describe instruments on a unit, for example: LIC100
• The first letter in an instrument tag, like LIC100, indicates which process is being measured (level).
• The second letter in the instrument tag, like LIC100, indicates the function of the instrument (indicator).
• The third letter in the instrument tag, like LIC100, indicates the function of the instrument (control).

P&ID Details:

• The legend on a P&ID shows what the symbols mean.
• A mechanical flow diagram shows metallurgy, line sizes, and flange ratings.
• An isometric diagram is a 3D drawing, but it’s not true.
• Cross hatching on a P&ID denotes a revision.
• A P&ID should: have a unique identification number, show connection between instruments, show the location of the instruments, and describe the function of the instruments.

Pressure Instruments:

• Combination Vacuum/Pressure: Includes two scales, negative and positive.
• Liquid Filled Gauge (Glycerin Filled): Used in areas with heavy vibration, as the glycerin is viscous and offers resistance.
• Tank Pressure Gauge: Found in cylinders and comes with alarms.
• Oil Gauge: Most important gauge, found on large pumps and compressors.
• Capillary: Differential pressure tube filled with clean fluids like silicone, glycerin, or water, used for duty processes or acids.
• Vacuum Gauge: Used for less heat applications.
• Manometer: Filled with water or mercury, usually in furnaces where a slightly negative pressure is desired, also found on blowers.
• Digital Gauge: Contains a diaphragm, easier to read.
• Delta p Transmitter: Measures differential pressure in two related pressures, found in flow and level applications.
• Pneumatic Transmitter: Used in spark concern areas, should have a gauge next to them in areas with no electricity.
• Smart Pressure Transmitter: Recalibrated in remote locations, ideal for time and date stamps.

Control Types

• Local Control
• Remote Board Control
• Computer Control (DCS)
• Direct Acting Controller
• Reverse Acting Controller
• Cascade Control
• Split Range Control
• Ratio Control
• Programmable Logic Controller (PLC)

Controller Tuning Parameters

• Proportional Band (Gain)
• Integral (Reset)
• Derivative (Rate)

Test your knowledge on various process symbols used in engineering diagrams. This quiz covers electronic, pneumatic, and digital signals, as well as different types of valves and pumps. Challenge yourself to identify and understand these essential symbols in the field.