on video What is a P&ID Diagram?

 “What in the world is a P&ID Diagram?” 

In industry, these are piping and instrumentation diagrams. P&ID for short.

Most manufacturing facilities have compressed air, steam, chilled water, and other processes that require the use of piping. 

All of these forms of energy and processes require instrumentation to control them which is usually in the form of valves and gauges, along with pumps and accumulators. 

A P&ID diagram will have all of these for a maintenance person, operator, engineer, or other employees to read and perform their job.

P&IDs are schematic representations of pipelines, equipment, instrumentation, and control systems found in process environments such as Oil Refineries, Chemical Plants, Paper Mills, and Cement Plants, etc.

The symbols contained in P&IDs represent the equipment in the process such as actuators, sensors, and controllers.

Process equipment such as valves, instruments, and pipelines are identified by codes and symbols.

As well as devices and pipelines, a P&ID will commonly contain information on vents, drains, and sampling lines as well as flow directions, control IO and Interconnection References.

The Instrumentation codes listed in P&IDs follow a standard format, after some practice in reading P&IDs you will know these codes by heart, but in the meantime, there are many resources on the web where you can download these tables for reference.

The first letter of the code identifies the parameters that are being controlled or monitored for example Flow, Temperature, Level or Pressure.

The next letter is used to define the type of control device being used, for example, Transmitter, Valve or Controller.

The number refers to the logical numerator.

For example, we may have a system with 4 temperature transmitters, it makes sense to identify these as  TT01,  TT02,  TT03, and  TT04.

Let’s consider for a moment an instrument on a P&ID named  FV01. Looking up the code for this we could tell this is a Flow Valve numbered 01.

Symbols, circles, and lines are used to represent instruments and to show how they are connected to the rest of the system.

Now that we know our device FV01 is represented by a circle, we can also tell from the P&ID where the instrument or device is located.

The presence or absence of a line in the circle determines the location of the physical device. Let’s take a look at how these are commonly represented.

– NO LINE: The instrument is located in the field near the process & operator

– SOLID LINE: The instrument is located in a control room (accessible to the operator)

– DOTTED LINE: The instrument is not directly accessible

The piping or connection lines on the P&ID also tell us about the instrument, for example, a solid line would indicate the interconnection is via pipework whereas a dotted line would indicate an electrical connection.

It is worth familiarising yourself with the different types of connection symbols as this can give you an insight into the function of an instrument even before you know its code.

 “What in the world is a P&ID Diagram?” 

In industry, these are piping and instrumentation diagrams. P&ID for short.

Most manufacturing facilities have compressed air, steam, chilled water, and other processes that require the use of piping. 

All of these forms of energy and processes require instrumentation to control them which is usually in the form of valves and gauges, along with pumps and accumulators. 

A P&ID diagram will have all of these for a maintenance person, operator, engineer, or other employees to read and perform their job.

P&IDs are schematic representations of pipelines, equipment, instrumentation, and control systems found in process environments such as Oil Refineries, Chemical Plants, Paper Mills, and Cement Plants, etc.

The symbols contained in P&IDs represent the equipment in the process such as actuators, sensors, and controllers.

Process equipment such as valves, instruments, and pipelines are identified by codes and symbols.

As well as devices and pipelines, a P&ID will commonly contain information on vents, drains, and sampling lines as well as flow directions, control IO and Interconnection References.

The Instrumentation codes listed in P&IDs follow a standard format, after some practice in reading P&IDs you will know these codes by heart, but in the meantime, there are many resources on the web where you can download these tables for reference.

The first letter of the code identifies the parameters that are being controlled or monitored for example Flow, Temperature, Level or Pressure.

The next letter is used to define the type of control device being used, for example, Transmitter, Valve or Controller.

The number refers to the logical numerator.

For example, we may have a system with 4 temperature transmitters, it makes sense to identify these as  TT01,  TT02,  TT03, and  TT04.

Let’s consider for a moment an instrument on a P&ID named  FV01. Looking up the code for this we could tell this is a Flow Valve numbered 01.

Symbols, circles, and lines are used to represent instruments and to show how they are connected to the rest of the system.

Now that we know our device FV01 is represented by a circle, we can also tell from the P&ID where the instrument or device is located.

The presence or absence of a line in the circle determines the location of the physical device. Let’s take a look at how these are commonly represented.

– NO LINE: The instrument is located in the field near the process & operator

– SOLID LINE: The instrument is located in a control room (accessible to the operator)

– DOTTED LINE: The instrument is not directly accessible

The piping or connection lines on the P&ID also tell us about the instrument, for example, a solid line would indicate the interconnection is via pipework whereas a dotted line would indicate an electrical connection.

It is worth familiarising yourself with the different types of connection symbols as this can give you an insight into the function of an instrument even before you know its code.