ANSI/ISA S5.5-1985: Graphic Symbols for Process Displays

Examples of process equipment popularly used in industries—such as refineries, chemical plants, and wastewater treatment plants—are pumps, valves, vessels, filters, coolers, boilers, engines, compressors, storage tanks, gearboxes, furnaces/heat exchangers, pulsation dampeners, and pipelines. To enhance the ease of use for personnel who operate process equipment, graphical symbols map out the processes. ANSI/ISA S5.5-1985: Graphic Symbols for Process Displays establishes a system of graphic symbols for process displays that are used by plant operators, engineers, etc., for process monitoring and control.

What Is Process Equipment?

Process equipment (also referred to as technological equipment) is any device, tool, or machine used in industrial processes to change raw materials into finished products. It is used in several applications like water treatment, steam power generation, pipelines, saltwater disposal, etc., where chemical or mechanical methods are applied. It is designed to perform specific tasks, such as storing materials, containing chemical reactions, and controlling flow of materials through process piping, and other activities.

Process equipment is fundamental for ensuring that manufacturing processes run safely, smoothly, and efficiently, and it is equally important that the graphic symbols for process displays provide easily understandable representation of the process. This helps operators and other personnel stay safe at work.

What Are the Benefits of Graphic Symbols for Process Displays?

ANSI/ISA S5.5-1985 specifies that its resulting benefits are intended to be as follows:

• A decrease in operator errors
• A shortening of operator training
• Better communication of the intent of the control system designer to the system users.

What Is ANSI/ISA S5.5?

ANSI/ISA S5.5-1985 specifies a system of graphic symbols intended to depict processes and process equipment that are suitable for use in the chemical, petroleum, power generation, air conditioning, metal refining, and numerous other industries. The system is intended to facilitate rapid comprehension by the users of the information that is conveyed through displays, and to establish uniformity of practice throughout the process industries.

Though the American National Standard may make use of standard symbols now used for piping and instrument diagrams, logic diagrams, loop diagrams, and other documents, the symbols of ANSI/ISA S5.5-1985 are generally expected to be used in ways complementing existing types of engineering documents.

The symbols are suitable for use on Visual Display Units (VDUs), such as Cathode Ray Tubes (CRTs). They should ensure maximum compatibility on process VDUs with related symbols used in other disciplines.

Process Displays

The graphic symbols for process displays in ANSI/ISA S5.5-1985 divided into 13 related groups:

1. Connectors
2. Containers and Vessels (subgroups: Process and Storage)
3. Electrical
4. Filters
5. Heat Transfer Devices
6. HVAC (Heating Ventilating and Air Conditioning)
7. Material Handling
8. Mixing
9. Reciprocating Equipment
10. Rotating Equipment
11. Scrubbers and Precipitators
12. Separators
13. Valves and Actuators

Each of these groups (an associated classification of similar symbols) are further broken up by process equipment. Each process equipment (e.g., transformer, cooling tower, rotary feeder, turbine, pump, electrostatic precipitator, cyclone separator, butterfly valve, relief valve, etc.) in ANSI/ISA S5.5-1985 is depicted by a unique symbol.

ANSI/ISA S5.5-1985: Graphic Symbols for Process Displays is available on the ANSI Webstore.