DXF, DEXPI, and the Future of Interoperability in EPC Workflows

By Anand George

Introduction: Bridging the Format Divide

Every engineering team has faced it:

  • P&IDs from vendors in PDFs
  • Native drawings in AutoCAD (.DWG/.DXF)
  • Smart P&ID tools demanding structured inputs (DEXPI, ISO 15926)

With so many formats — and so few bridges between them — true interoperability remains an elusive goal.

This post explores the role of DXF and DEXPI, the two formats most critical to engineering data exchange, and how we at Storm Consulting are building tools that finally bring these workflows together.

DXF: The CAD Workhorse

DXF (Drawing Exchange Format) is the most common bridge between CAD tools. Created by Autodesk, it’s a plain-text representation of .DWG files that can be read, parsed, and processed by external software.

Pros:

  • Universally supported in CAD tools
  • Easy to convert from AutoCAD
  • Good for geometry and layout

Limitations:

  • Lacks semantic meaning (it knows a circle exists, not that it’s a pump)
  • Not inherently structured — needs external parsing
  • Doesn’t capture relationships (e.g., flow direction)

DXF is excellent for layout, but not enough for intelligent automation on its own.

DEXPI: The Semantic Standard

DEXPI, on the other hand, is designed to describe:

  • Equipment, instrumentation, piping systems
  • Properties (e.g., size, material, tag)
  • Connections and flows between elements

It’s built on ISO 15926 and XML/OWL — making it perfect for:

  • Smart P&ID systems
  • Data-driven validation
  • Integration with digital twins

Trade-off:

  • Requires conversion and mapping from visual sources
  • Not easy to author manually
  • Needs standardized classification

DEXPI is the end goal of interoperability — structured, relational, and smart.

Our Approach: From CAD Geometry to Digital Intelligence

At Storm Consulting, we build tools that:

  1. Extract geometric entities from DXF

    • Lines, arcs, blocks, text

  2. Map these to known symbols or templates

    • Instrument loops, valves, chevrons

  3. Build a graph of elements and flows

    • Nodes = equipment/instruments
    • Edges = lines/flows

  4. Export to DEXPI

    • Clean, structured, machine-readable data

This gives engineers the best of both worlds: familiar CAD drawings and intelligent automation.

Why Interoperability Matters

  • Vendor Diversity: Different vendors = different tools = format chaos
  • Digital Twin Readiness: Without structured data, there’s no “twin” — just a drawing
  • Audit and Traceability: Structured data makes change tracking and QA feasible
  • Cross-Platform Integration: From SmartPlant to COMOS to internal systems

Interoperability reduces rework, improves collaboration, and future-proofs your data.

Real-World Use Case

One client received P&IDs from multiple vendors:

  • Some as DXF
  • Some as PDFs
  • None with metadata

Using our tools:

  • PDF-based P&IDs were converted to DXF-like representations
  • Symbols were matched using templates
  • Lines were traced and graphs constructed
  • Final export was done in DEXPI for SmartPlant import

The result: a unified, machine-readable dataset across 3 vendor packages — without rewriting a single drawing manually.

Conclusion: The Future Is Structured and Connected

CAD will always be important — but CAD alone isn’t enough. To build smarter workflows, digital twins, and AI-powered tools, engineering data needs to move beyond lines and circles.

By connecting DXF and DEXPI, we enable that transition — helping EPCs and plant owners turn drawings into data, and data into value.

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