ICE 420- Instrumentation and Control Engineering C2

Process technology

It refers to the techniques, tools,

equipment, and methods used to transform raw materials

into finished goods or desired outputs. It encompasses

the design, development, and operation of systems and

equipment in industries such as manufacturing, oil and

gas, pharmaceuticals, and food production.

BACK FLOW DIAGRAM

PROCESS FLOW DIAGRAM

PIPING AND INSTRUMENTATION DIAGRAM

What are the different process diagrams?

BACK FLOW DIAGRAM

It is a simplified representation of a process that shows

the main process units or blocks and their

interconnections using straight lines. It provides a high-

level overview without including detailed equipment or

process information.

Input-output diagrams

They are not very detailed and are most useful in the early stages of process development.

PROCESS FLOW DIAGRAM

It provides a more detailed representation of a process

compared to a BFD. It includes major equipment,

process flowlines, operating conditions (temperature,

pressure, etc.), and key process parameters but avoids

showing piping details or minor instruments.

PIPING AND INSTRUMENTATION DIAGRAM

It is a highly detailed schematic that shows al piping, equipment, valves, and instrumentation in the process.

PIPING AND INSTRUMENTATION DIAGRAM

It is the overall design document for a process plant

Set of symbols

are used to depict mechanical equipment, piping, piping components, valves, equipment drivers and instrumentation and controls.

INSTRUMENTATION SYMBOLS

LINE SYMBOLS

These are the types of Instrumentation Symbols

SYMBOLS

are used to provide information about the process

Symbols

It may represent devices in the system or indicate how devices are connected to each other.

LINE SYMBOLS

are used in diagrams like Piping and

Instrumentation Diagrams (PSID) and Process Flow

Diagrams (PFD) to represent the connections between

instruments, equipment, and the process itself.

PROCESS LINE SYMBOLS

SIGNAL LINE SYMBOLS

TYPES OF LINE SYMBOLS

Process Line Symbols

are visual representations used in diagrams like P&IDs and PFDs to show how process materials (e.g., liquids, gases, or solids) flow

through the system and how instruments connect to the process.

Thick Solid Lines

represent the main process piping that transports materials like fluids or gases between major equipment.

Thin Solid Lines

represent instrument connections to the process, such as tubing for transmitting pressure, temperature, or flow measurements from the process to an instrument.

Signal Line Symbols

are used to represent the type of signal used to connect instruments, controllers, and final control elements.

Mechanical Signal

represents a physical or mechanical linkage

Electrical Signal

represents an electrical connection

Pneumatic Signal

represents a signal transmitted via compressed air, commonly used in older or specific industrial systems.

Hydraulic Signal

represents a signal transmitted via a hydraulic fluid system.

Software/ Digital Signal

represents communication between devices using digital protocols.

VALVE AND ACTUATOR SYMBOLS

These are used to represent the function, operation, and fail-safe positions of valves and their actuators in a process system.

Valve

are usually drawn as a bow tie shaped symbol.

Tag Number

It is the complete alphanumeric code assigned to an instrument, combining both the Functional Identifier and Loop Identifier. It uniquely identifies each instrument in a plant or system.

Functional Identifier

It is the letter code within the tag number that specifies the type and function of the instrument (e.g., pressure, temperature, flow measurement, or control).

Loop Identifier

It is the numeric portion of the tag number that indicates the specific control loop or system the instrument belongs to. For example, instruments with "100" in their tag numbers belong to loop 100, such as a temperature monitoring loop