The course will explain the function of the various instruments used in the process industry; diagram the process control elements in a control loop; utilize terms and symbols in instrumentation; and interpret process flow diagram and piping and instrumentation drawing.
Process Instrumentation provides an overview of:
- the instruments used in process industries and the process technician’s role in their usage
- common control schemes used in the process industry, including terminology, process variables, symbology, types of control loops, and basic troubleshooting of a small control system
- system components such as flowmeters, pressure transmitters, transducers, switches, programmable logic controllers, different types of analyzers
A key focus within the (4) labs is a focus on learning how to read and interpret Piping & Instrumentation and Process Flow Diagrams. Students will need to demonstrate the ability to identify process components and instruments on the drawings and “in the field” within the HOT-1 and HOT-3 student “hands on training” units (HOT 1 & HOT 3 Units).
Core NAPTA Learning Outcomes are:
- Identify process variables, elements and instrumentation used to measure pressure, temperature, level, flow and analytics.
- Identify symbology, hardware, and instrumentation signal transmission. instruments are used to sense, measure and transmit this information to the control system.
- Draw a control loop.
- Identify and troubleshoot instrumentation malfunctions. their interrelationships.
- Describe how a control loop works.
Specific Chapter Objectives
1 Introduction to Instrumentation
- 1.1 Discuss the evolution and importance of process instrumentation to the process industries.
- 1.2 Explain the importance of monitoring process variables, the importance of instrumentation to the process technician, and the operator’s role in safety.
- 1.3 Categorize the major process variables controlled in the process industries and define their units of measurement.
- 1.4 Describe instrumentation with regard to location, function, type, and signal produced.
- 1.5 Examine the relationship between common process variables.
2 Process Variables, Elements, and Instruments: PRESSURE
- 2.1 Identify the concept of pressure and the three components that affect the force exerted by molecules.
- 2.2 Manipulate units of measurement associated with pressure and pressure instruments.
- 2.3 Illustrate common types, purpose, and operation of pressure sensing or pressure measuring instruments used in the process industries.
- 2.4 Using a standard calculator and conversion formulas, convert between the following pressure scales.
3 Process Variables, Elements, and Instruments: TEMPERATURE
- 3.1 Explain temperature and the effects of heat energy on the movement of molecules.
- 3.2 Calculate units of measure associated with temperature and temperature instruments.
- 3.3 Illustrate common types, purpose, and operation of temperature sensing and measurement devices used in the process industries.
- 3.4 Using conversion formulas, complete Fahrenheit and Celsius conversions.
4 Process Variables, Elements, and Instruments: LEVEL
- 4.1 Classify terms associated with level and level instruments.
- 4.2 Predict the relationship between temperature and level measurement as it relates to the density and volume of liquid.
- 4.3 Identify the most common types, purposes, and operation of level-sensing/measuring devices used in the process industries.
5 Process Variables, Elements, and Instruments: FLOW
- 5.1 Define terms associated with flow and flow measurement.
- 5.2 Identify the most common types, purpose, and operation of flow sensing and measuring devices used in the process industries.
- 5.3 Explain the difference among total volume flow, flow rate, mass flow, and volumetric flow.
6 Process Variables, Elements, and Instruments: ANALYTICS
- 6.1 Define terms associated with analytical instruments.
- 6.2 Identify the most common types of analytical devices used in the process industries and their purposes.
- 6.3 Identify common types of miscellaneous measuring devices.
- 6.4 Discuss how analytical data affects the role of the process technician and how the process technician affects the operation of analytical instrumentation.
7 Process Diagrams and Instrumentation Symbology
- 7.1 Describe the types of drawings that contain instrumentation an operator might use.
- 7.2 Explain the lettering and numbering standards based on ISA instrumentation symbols.
- 7.3 Demonstrate how to determine the instrument type or signal line type from the symbol information.
- 7.4 Using a legend, locate and identify instrumentation on a PFD or P&ID drawing.
8 Switches, Relays, and Alarms
- 8.1 Define the purpose and function of a switch.
- 8.2 Define the following terms associated with switches used in process control.
- 8.3 Given a drawing, picture, or actual device, identify and describe basic switch devices used in process control.
- 8.4 Explain how relays are used in the process industry.
9 Signal Transmission and Conversion
- 9.1 Explain the purpose and operation of transmitters.
- 9.2 Describe methods for protecting integrity and reliability of signal transmission.
- 9.3 Recall types of common transmissions.
- 9.4 Discuss the purpose and operation of signal converter equipment.
- 9.5 Describe wet leg and dry leg instrument lines.
- 9.6 Perform scaling calculations.
- 9.7 Explore wireless technologies—Industry 4.0—and open internet protocol transmission/addressing.
10 Introduction to Control Loops: Simple Loop Theory
- 10.1 Explain the function and elements of process control loops.
- 10.2 Explain the differences between open and closed control loops.
- 10.3 Classify the functions of a control scheme.
- 10.4 Explain signal transmission.
11 Control Loops: Primary Sensors, Transmitters, and Transducers
- 11.1 Describe the function of measuring instruments for pressure, temperature, level, and flow and their role in the overall control loop process.
- 11.2 Describe the purpose and operation of the elements in a control loop.
- 11.3 Discuss differential pressure in relation to the process input to the transmitter.
- 11.4 Compare and contrast the transmitter input and output signals.
- 11.5 Describe the function of a current to pneumatic or pneumatic to current transducer (signal converter).
- 11.6 Describe the relationship between a 3 PSIG to 15 PSIG air signal and a 4 mA to 20 mA electric signal.
- 11.7 Given a process control scheme, explain how a control loop functions.
12 Control Loops: Controllers and Final Control Element Overview
- 12.1 Explain terms associated with controllers.
- 12.2 Explain bumpless transfer of automatic to manual and manual to automatic control.
- 12.3 Describe the process for switching from automatic control to manual control and from manual to automatic on a local controller.
- 12.4 Given a drawing or actual device, describe the application and operation of the following.
- 12.5 Describe three types of final control elements and provide an application for each type.
13 Control Loops: Control Valves and Regulators
- 13.1 Given a drawing or actual device, identify the following components of a control valve system.
- 13.2 Define terms associated with valves and other final control elements and operating scenarios in which they are desirable.
- 13.3 Discuss the purpose and operation of actuators and valve positioners and explain why the action of a valve actuator may not correspond with the position of the valve.
- 13.4 Explain how a controller’s output signal can be reversed at the valve, a control scheme that uses such a signal, and effects on the valve’s fail-safe position upon loss of instrument air.
- 13.5 Explain the purpose and operation of the following.
- 13.6 Identify the location and use of pressure regulators used in process control, including.
14 Controllers
- 14.1 Explain the following states and conditions associated with process dynamics, process control, and controllers.
- 14.2 Define the following terms associated with process recording.
- 14.3 Identify tuning modes and troubleshooting for selected controller tuning errors and process problems.
15 Control Schemes
- 15.1 Identify and describe types of control schemes.
- 15.2 Describe a control scheme that allows the following modes.
16 Advanced Control Schemes
- 16.1 Contrast the basic rationale for advanced control schemes versus simple control loops.
- 16.2 Explain the purpose of a cascaded control scheme.
- 16.3 Explain the function of a ratio (fractional) control scheme.
- 16.4 Explain the purpose and function of a split-range control scheme.
- 16.5 Explain the purpose and function of a multivariable control scheme and steps required to change instrument controllers without bumping te process.
17 Introduction to Digital Control
- 17.1 Explain the development of digital control.
- 17.2 In general terms, describe the difference between analog and digital controllers.
- 17.3 Define the following terms associated with process control schemes.
- 17.4 In general terms, describe how a digital controller transmits an output signal to an analog final control element and how an analog controller transmits to a digital controller.
18 Programmable Logic Controls
- 18.1 Explain the purpose of and terms associated with programmable logic control (PLC).
- 18.2 Explain how ladder logic applies to programmable logic control.
19 Distributed Control Systems (DCSs)
- 19.1 Explain the purpose of a DCS.
- 19.2 In general terms, describe the operation of a DCS.
- 19.3 Explain the function of a multiplexer/demultiplexer.
- 19.4 Explain advantages of a DCS over an analog control system.
- 19.5 Explain how DCSs interact with analytics/trending, intrinsically safe display devices/tablets, and cyber security issues.
20 Instrumentation Power Supply
- 20.1 Provide an overview of plant power supply systems.
- 20.2 Identify the purpose and components of uninterruptible power supply (UPS) systems.
21 Emergency Shutdown (ESD), Interlocks, and Protective Devices
- 21.1 Identify terms associated with emergency shutdown systems.
- 21.2 Describe common types of alarms.
- 21.3 Identify ways of avoiding shutdowns.
- 21.4 Explain methods for testing and resetting ESDs and issues that are associated with bypassing an ESD logic.
22 Instrumentation Malfunctions
- 22.1 Recall the methods used for determining if a sensing or measuring device is malfunctioning.
- 22.2 Describe the failure modes of the following.
- 22.3 Explain how a control loop will respond to typical malfunctions in the following.
23 Instrumentation Troubleshooting
- 23.1 Explain the extent of an operator’s role when troubleshooting problems with process instruments and the importance of process knowledge in troubleshooting.
- 23.2 Identify typical malfunctions found in primary sensing elements and transmitters.
- 23.3 Explain the methods used for determining if a sensing or measuring device is malfunctioning.
- 23.4 Explain the importance of communication between the board technician and the outside process technician when troubleshooting a control loop problem.
- 23.5 Explain the proper use of tools and equipment related to process troubleshooting.
- 23.6 Discuss safety and environmental issues related to troubleshooting process instruments.