Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

P&ID - Piping and Instrumentation Diagram

Schematic illustration of a functional relationship between piping, instrumentation and system components.

P&ID's shows all piping including physical sequences of branches, reducers, valves, equipment, instrumentation and control interlocks.

The P&ID's are used to operate process systems.

A P&ID should include:

  • Instrumentation and designations
  • Mechanical equipment with names and numbers
  • All valves and their identifications
  • Process piping, sizes and identification
  • Miscellaneous - vents, drains, special fittings, sampling lines, reducers, increasers and swagers
  • Permanent start-up and flush lines
  • Flow directions
  • Interconnections references
  • Control inputs and outputs, interlocks
  • Interfaces for class changes
  • Seismic category
  • Quality level
  • Annunciation inputs
  • Computer control system input
  • Vendor and contractor interfaces
  • Identification of components and subsystems delivered by others
  • Intended physical sequence of the equipment

The figure below illustrates a very small and simplified P&ID:

Piping and Instrumentation Diagram - P&ID

A P&ID should not include:

  • Equipment rating or capacities
  • Instrument root valves
  • Control relays
  • Manual switches and indicating lights
  • Primary instrument tubing and valves
  • Pressure temperature and flow data
  • Elbows and similar standard fittings
  • Extensive explanatory notes

Insert piping components to your Sketchup model with the Engineering ToolBox Sketchup Extension

Engineering ToolBox Sketchup Extension - piping components

3D Engineering ToolBox - draw and model technical applications! 2D Engineering ToolBox - create and share online diagram drawing templates! Engineering ToolBox Apps - mobile online and offline engineering applications!

Unit Converter


















































6.27.14

.