Gas facilities are high-risk areas with complex ecosystems. Disproportionate routing arrangements can cause safety issues and lead to leaks.

Engineering design combined with pipe stress analysis can safeguard your facility through risk assessment based on verified data.

In this blog, we explain why we apply piping engineering knowledge to design gas processing facilities and how we overcome challenges in process piping design.

Why is engineering design needed for gas facilities?

Plants handle flammable, high-pressure, and often corrosive gases and rely on pipeline structure and quality for optimum gas processing.

Through engineering design, safety systems are incorporated to prevent piping system failures and ensure that the facility can withstand hazardous conditions.

Engineering design ensures that the following criteria are met in the design stage itself and prevent manufacturing errors:

  • Optimal equipment arrangement
  • Compliance with local government regulations
  • Cost estimation and efficiency
  • Accommodate future expansion activities
  • Mitigate equipment failures and unplanned shutdowns
  • Minimise energy consumption

In addition to these, safety evaluation plays a crucial role in strengthening mechanical integrity.

How can pipe stress analysis help during the engineering design process?

Stress analysis for gas plant piping is commonly performed during the design phase to identify potential hazards to the piping systems at an early stage.

It is particularly useful in gas processing facilities for:

  • Steam and utility piping
  • Hot gas and regeneration lines
  • High-pressure gas pipelines
  • Vessel-connected piping
  • Cryogenic and LNG piping
  • Flare and relief systems
  • Compressor suction and discharge piping

A detailed assessment of pipes provides valuable insights into the mechanical equipment needed to enhance system flexibility and prevent operational failures that could cause hazards.

Here are some of the conditions considered during a pipe stress analysis:

Pipe sagging

The combined weight of the pipe and fluids putting pressure on the valves, causing excessive deflection.

Excessive stresses

Internal pressure, wind, weight, thermal expansion or other occasional loads that exceed allowable code limits.

Support deficiency

Incorrect positioning, support overload, insufficient restraints, and the need for springs, hangers, guides, or snubbers.

Potential leakage points

High stresses in flanged joints, welded connections, and equipment nozzles may increase the likelihood of leaks.

Medium Pressure or Vibrations

Flows and vibrations in pipes induced by unnatural frequencies that could cause mechanical fatigue and disrupt flow.

Design and operating challenges in Oil & Gas facilities

Project planning is one of the critical phases in gas processing facilities. Design engineers must evaluate all possible operating and failure scenarios before the project advances to the fabrication phase.

Here are some practical hands-on concerns that come up while designing a gas processing facility:

Balancing plot space with safety requirements

Fitting piping and equipment within the pre-decided plot while also meeting spacing rules according to codes and standards.

Keeping pace with late-stage project changes

Changes delayed during P&IDs or process design stages can cascade into piping, stress, and structural rework. Plant engineers consider changes as they arrive and move targets accordingly.

Material selection under corrosive service

Selecting piping materials compliant with ASTM (American Society for Testing and Materials) while balancing cost, availability, and structural relevance. Decisions taken during this activity can affect fabrication and long-term integrity.

Operability under upset conditions

Protecting piping systems from overstress and unsafe conditions by designing relief and blowdown systems to handle abnormalities—compressor trip, emergency shutdown.

Maintaining process temperature

Prevent freezing, control insulation effectiveness, and maintain the appropriate temperature condition inside the facility. Design engineers must create a plan that allows for inspection and replacement without major disassembly.

Knowledge and documentation continuity

Original as-built models and design basis records are critical for safe modifications and troubleshooting. Poor documentation hand-off can become an operational challenge as the facility ages.

Design changes after a stress analysis

Since gas processing facilities rely extensively on piping systems for their operation, a pipe stress analysis report is a valuable engineering reference that provides design engineers with guidance for modelling safe, reliable, and code-compliant piping systems.

The results from the analysis can be categorised systematically, allowing the corresponding design modifications to be identified and implemented in this manner:

Support system changes

  • Shift support locations to manage span—unsupported pipe length—and load distribution
  • Convert rigid supports to spring hangers based on the changes in thermal movement
  • Add guides and anchors to control lateral movement and provide flexibility to required parts of the piping system
  • Reduce spans between pipes to avoid excessive stress, sagging, and vibration

Pipe rerouting for flexibility

  • Add loops and offsets to increase flexibility during thermal expansion
  • Change pipe routing to naturally absorb insulation, thermal movement, etc. instead of relying solely on pipe materials
  • Reduce loads on existing pipelines and equipment by modifying tie-in locations
  • Shift anchor locations to redistribute pipe loads and reduce stress concentration at critical points

Revisiting material and components

  • Switching material classification if thermal or mechanical properties don’t meet stress requirements
  • Replacing regular fittings with reinforced fittings—long radius elbows, expansion joints, reinforcement pads—at branch connections having high stress concentrations
  • Increasing pipe wall thickness in high stress zones identified during the analysis, particularly in branch connections and bends.

Modifying structural steel design

  • Adjust spacing or capacity to accommodate revised support loads from stress analysis output
  • Add intermediate steel members to support additional pipe supports identified as necessary
  • Prevent excessive pipe movement by installing snubbers near equipment with the possibility of resonance due to vibration

Revising 3D models and clash checks

  • Update piping 3D models with new supports or reroutes and reflect these changes in isometrics, bills of materials for procurement and fabrication
  • Coordinate changes in 3D models of support load changes with structural teams and confirm revised loads with equipment vendors for sign-offs.

Prevent costly piping issues with expert stress analysis & Engineering Design

Process piping design is an intricate activity involving a systematic routing approach to ensure efficient and balanced distribution.

Sedin Engineering combines design engineering and pipe stress analysis, using CAESAR II and other latest technologies, to strengthen piping system design by detecting risks and deficiencies before construction and material procurement.

Our expert piping design engineers endeavour to deliver precise, code-compliant designs with minimal design flaws while ensuring operational reliability and maintainability.

Optimise your gas processing facility through robust and efficient engineering design solutions. Contact us for a detailed engineering review.