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AI process flow

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AI process flow, Pricing: Free, New!

Business process flow template

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Business process flow template, Pricing: Free

Procurement process flow example

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Paid Account

Procurement process flow example, Pricing: Paid Account

Process flow FAQs

A process flow diagram (PFD) is a type of flowchart that illustrates the relationships between major components at an industrial plant, most often used in chemical engineering and process engineering to document, improve, or model a process.

PFDs are used to document processes for better understanding and training, standardize processes for optimal efficiency, study processes to identify bottlenecks and inefficiencies, and model new or improved processes.

A typical PFD includes major equipment with names and ID numbers, process piping, flow direction, control valves, bypass and recirculation systems, operational data like pressure and temperature, fluid composition, and process stream names.

A PFD shows the relationships between major components and process flow, while a piping and instrument diagram (P&ID) is more technical, adding detailed mechanical information about equipment, piping, instruments, valves, vents, and drains for technical experts.

A block flow diagram is a type of PFD that shows multiple unit processes at a plant as an overview with less detail. In these diagrams, each block depicts a single piece of equipment or a stage in a process, typically flowing from left to right.

Follow these basic steps:

  • Define the scope and detail level needed. 

  • Research the process through observation and interviews. 

  • Create an initial draft of the diagram.

  • Confirm the draft with people involved in the process. 

  • Make necessary changes in collaboration with those involved.

The most common PFD symbols come from ISO, DIN, and ANSI standards, though many companies use their own similar symbols that vary in detail as processes become more complex.

PFDs typically omit detailed items like pipe classes and line numbers, process control instruments, minor bypass valves, isolation and shutoff valves, maintenance vents and drains, and relief or safety valves.

Everything you need to make a diagram

In addition to our online diagram maker, Lucidchart offers support and training resources to help you branch out to any type of diagram.

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