P&I diagrams are part of the plant documentation. As standard, P&I diagrams are used for the following:
- Representation of a process engineering piping
- Representation of a plant overview with associated instrumentation
- Functional overview drawings of machines.
P&I diagrams are often called P&IDs (Piping and Instrumentation Diagrams) or P&I schemes (Piping and Instrumentation Schemes). The term "P&I diagram" is used in EPLAN.
Information in a P&I diagram
The information in a P&I diagram is split into basic information and additional information. Basic information is:
- Functional purpose and type of the apparatus and machines, including engines, conveyor equipment and installed reserves
- Identification number of the apparatus and machines, including engines
- Characteristic sizes of apparatus and machines
- Pipings with designation of nominal width, pressure level, material and version, e.g. via a piping number and piping class or identification number
- General information on the apparatus, pipings, and control valves
- Measurement, regulation, and controlling functions with identification numbers
- Characteristic information about engines.
The P&I diagram can also contain the following additional information:
- Designation, flow rate, and quantity of energy and energy carriers
- Flow paths and directions of energy and energy carriers
- Type of important devices for measuring, control, and regulation processes
- The main materials of apparatus and machines
- Platform height and approximate vertical position of the part sections
- Reference identification of control valves
- Designations of part sections.
Page Type "P&I Diagram"
P&I diagrams are created on pages of page type "P&I diagram". The origin of the pages is at the lower left. When changing standards, these pages are never rotated.
See also
PCT Loops / PCT Loop Functions in P&I Diagrams
Containers and Container Connection Points in the P&I Diagram