In many industries, engineers will create a blueprint for equipment
and control layout called a piping and instrumentation diagram or P&ID.
In this video, we'll walk through codes and symbols specifically for oil and gas production equipment.
So you can read and understand P&ID's in this industry.
Process diagrams can be broken down into two major categories piping and instrumentation diagram and process flow diagrams.
A P&ID is complex while a PFD is more of an overview of a process.
A flow diagram is a simple illustration that uses process symbols to describe the primary flow path through the production equipment.
It provides a quick snapshot of the operating unit and includes all primary equipment and piping symbols that can be used to trace the flow of the well stream through the equipment.
Secondary flows complex, control loops, and instrumentation are not included.
These PFD's are more helpful for visitor information and new employee training.
Field technicians engineers and operators use P&ID's to better understand the process and how the instrumentation is interconnected.
Sales personnel and OEM's use P&ID's to spec equipment and build the vessels.
After some practice you'll become familiar with many of these codes and symbols,
but if you're just starting out or need a visual reference make sure to visit
our blog page which features a full list of symbols that you can download and keep on hand.
Stand alone physical instruments are indicated by a tag number with a circle around it.
Tag numbers are a series of letters and numbers that identify a device
as what it is controlling the type of device being used and the number assigned to it on the P&ID.
The first letter indicates the parameters being controlled monitored or measured.
The second letter tells the type of device being used.
There can be up to five letters used to further designate the function of the component and modify the meaning of the preceding letters.
For example, PC is a pressure controller while PIC is a pressure indicator controller.
This chart shows common abbreviations for what you would see and how it would be written on a P&ID.
However, there are many other abbreviations that you will see.
Such as this more comprehensive industry list.
The number below these letters is the numerator to help identify a specific component on a project within the control loop.
When there are multiples of the same device used in a diagram,
This number helps viewers to reference that specific instrument.
If you were looking at a list of the controls, you could look at the control loop number to find that specific device on the P&ID.
A viewer can use these critical tag numbers to reference additional process information for
that instrument which helps product sizing material selections and other variables.
You'll notice that some components such as check valves ball valves and isolation valves do not use tag numbers.
Typically, the information given with these will be limited to their symbol and the line size.
The circle combined with the presence or absence of a line determines the location of the physical device.
No line means the instrument is installed in the field near the process.
A solid line means the instrument is in a primary location in a central control room accessible to the operator.
A dashed line tells us that the instrument is in an auxiliary location in a central control loom not accessible to the operator.
A double solid line means that it is in a local control room or on a local control panel
While a double dashed line means it's in an auxiliary location in a local control room or local control panel.
Shared display means you can see the same information in several locations across a network and it can be accessed anywhere.
Shared control means you can change the parameters of that device remotely.
Some instruments are part of a distributed control system or DCS.
Where a user can select a specific controller or indicator and see it in one location such as on a terminal screen.
With today's computerized systems using virtual controllers like in PLC's and DCS's new P&ID symbols had to be developed.
If you take the same tag number symbol for a physical instrument and add a
square around it, it now means that it is part of a shared display and shared control in a DCS.
Different symbols for line types tell us about the instrument.
Users can identify how instruments connect to each other and what type of signal is being used.
Familiarize yourself with these different connection symbols by downloading a reference chart.
Typing symbols have various important uses you'll want to be familiar with.
One important symbol to note here would be the reducers.
This will help you identify when the piping changes sizes.
You'll see these sometimes immediately upstream or downstream of a control device.
This information is helpful for understanding flow capacity and sizing.
P&ID symbols can sometimes change from company to company.
This is especially true with control valve symbols.
This chart of common control valve symbols can be downloaded for reference, but always consult the P&ID legend if available.
Here are the symbols for pumps, tanks, and other types of equipment.
The most common pumps used here in the oil and gas industry are screw, progressive cavity, and reciprocating pumps.
The most common tanks are dome roof tanks.
To download a complete package of the PDF's and P&ID's referenced in this video, visit the link below.
To speak with an expert about identifying elements of your P&ID, contact your local Kimray store or authorized distributor.