Compressed Air Process Diagram



Process Instrumentation Diagram (P&ID) Symbols

A Process Instrumentation Diagram (P&ID) is a detailed diagram in the process industry which shows the piping and process equipment together with the instrumentation and control devices. Here’s a breakdown of its key features:

  1. Overview: P&IDs represent the physical arrangement of equipment and the piping required to connect each piece of equipment. They serve as a roadmap for the design and operation of a process facility.
  2. Components: These diagrams typically include:
    • Process equipment like pumps, compressors, heat exchangers, tanks.
    • Piping systems, including pipe sizes, pipe material, and flow directions.
    • Instrumentation and control devices, like sensors (pressure, temperature, flow, etc.), controllers, and their interconnections.
    • Operational details, such as process conditions (pressure, temperature), fluid properties, and flow rates.
  3. Symbols and Notations: P&IDs use standardized symbols and notations to represent different components and control strategies. This includes valves, instrument symbols (like PT, TT), and line symbols.
  4. Purpose:
    • Design and Engineering: P&IDs are crucial in the design phase, helping to lay out the process flow and integrate equipment and control.
    • Operation and Maintenance: They are used to understand the process flow and for troubleshooting, maintenance, and modification of the process.
    • Safety and Compliance: P&IDs are essential for safety analysis and compliance with regulatory standards.
  5. Development and Usage: P&IDs are developed during the design phase of a project and are updated throughout the lifecycle of a facility to reflect any modifications.

CALMS is using standard symbols for compressed air and other utilities.

Sample CALMS P&ID:

Standard symbols for instrumentation used in CALMS

  1. Flow:
    • Instrument: FI (Flow)
    • Transmitter: FT (Flow Transmitter)
    • Control: FIC (Flow Indicating Controller)
  2. Pressure:
    • Instrument: PI (Pressure)
    • Transmitter: PT (Pressure Transmitter)
    • Control: PIC (Pressure Indicating Controller)
  3. Temperature:
    • Instrument: TI (Temperature)
    • Transmitter: TT (Temperature Transmitter)
    • Control: TIC (Temperature Indicating Controller)
  4. Dewpoint :
    • Instrument: DPI (Dewpoint)
    • Transmitter: DPT (Dewpoint Transmitter)
    • Control: DPIC (Dewpoint Indicating Controller)
  5. Power :
    • Instrument: J Ior PWRI (Power)
    • Transmitter: JT or PWRT (Power Transmitter)
    • Control: JIC or PWRIC (Power Indicating Controller)
  6. ​​​​​​​​​​​​​​Energy :
    • Instrument: EI (Energy)
    • Transmitter: ET  (Energy Transmitter)
    • Control: EIC or EIC (Energy Indicating Controller)
  7. Electric Current
    • Transmitter: CT  (Current Transmitter)
  8. Electric Current
    • Transmitter: CT  (Current Transmitter)
  9. Electric Current
    • Transmitter: CT  (Current Transmitter)
  10. Voltage
  11. Length
  12. Time
  13. Digital state
  14. Specific power
  15. Vibration
  16. Ultrasound
  17. Mass
  18. Velocity
  19. Volume
  20. Count
  21. Rate
  22. Ratio
  23. Mass flow

Table P&ID symbols in CALMS

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