- Service
Failure & Integrity Assessment
- Service
Piping Failure & Integrity Assessment
Evaluation of operating piping systems to identify failure risks before they become incidents. Structured around four assessment domains that account for the majority of piping incidents we see across refineries, petrochemical, and power plants.
REGION
Flange Leakage Assessment
Combined-load flange evaluation per ASME B31.3, Section VIII Div 1 App 2, PCC-1.
Overstress ID
Locate piping sections under excessive thermal, pressure, or mechanical load.
Nozzle Load
Pump, compressor, vessel nozzle verification per API 610 / 617 / vendor data.
Support Review
Support load, restraint config, spacing, spring hanger travel verification.
Flange Leakage Assessment
A flange leakage assessment verifies that critical bolted flange joints remain leak-tight under the combined effect of internal pressure, thermal expansion, and external piping loads.
What the assessment covers
- Flange stress check under combined internal pressure and external piping loads
- Bolt load verification across all service conditions
- Gasket seating pressure verification — operating and upset
- Thermal expansion and differential-thermal effect on the joint
- Assembly integrity assessment per ASME PCC-1
Standards applied
ASME B31.3
Section VIII Div 1 App 2
ASME PCC-1
When commissioned
- After a flange leak or weeping joint in service
- On critical flange joints during a new-build stress analysis
- When equipment nozzle shows leakage after thermal cycling
- During a turnaround — selecting joints needing re-gasketing
- For non-standard or custom flange designs
Overstress Identification
Pipe overstress identification is the assessment of operating piping against allowable stress limits to locate sections under excessive stress from thermal expansion, pressure, or mechanical loads. The first technical output of most integrity reviews — without knowing where stress is high, remediation cannot be prioritised.
What drives overstress
- Thermal expansion beyond the flexibility of the layout
- Operating temperature higher than the original design
- Pressure higher than the original design or upset condition
- Support or restraint configuration that over-restrains the line
- Support failure or subsidence that changes the load path
- Secondary structural movement (settlement, seismic event)
- Weight change from retrofit — insulation, cladding, attached items
How we identify it
- Walkdown or as-built review to confirm current configuration
- CAESAR II model update with current operating conditions
- Load case run against ASME B31.3 or B31.1 allowables
- Identification of overstressed sections with stress ratio
- Recommended remediation per section
Equipment Nozzle Load Evaluation
Verifies that forces and moments transferred from piping to connected equipment — pumps, compressors, turbines, vessels, exchangers — remain within the vendor or API allowable envelope. Excessive nozzle loads cause misalignment, nozzle cracking, shortened equipment life, and occasionally catastrophic failure.
Equipment we verify
- Pump nozzle loads per API 610
- Compressor nozzle loads per API 617 and vendor data
- Steam turbine nozzle loads per NEMA SM-23 or vendor data
- Pressure vessel, exchanger, and drum nozzle loads per vendor data
- Fired heater nozzle loads per vendor data and movement envelope
- WHRU tube-to-header interface verification
If first-iteration nozzle loads exceed the allowable envelope, we recommend the most economical remediation — rerouting, flexibility addition (loops, offsets, expansion joints), support or restraint change, or vendor concurrence on a relaxed envelope.
Support and Restraint Review
Evaluates the as-installed and as-operating condition of pipe supports, anchors, guides, and line stops to detect improper restraints, excessive support loads, or insufficient flexibility. Support walkdowns, spring hanger travel verification, and restraint configuration checks are the core of this assessment.
Scope of the review
Support load verification
Confirm that sustained, thermal, and occasional loads on each support remain within the manufacturer's capacity and within the structural steel's load envelope.
Restraint configuration review
Evaluate anchors, guides, and line stops to confirm they are correctly applied and do not over-restrain the line against thermal expansion or settlement.
Support spacing and placement
Assess support spacing to prevent excessive sag, vibration, or local overstress, per recognised practice and piping class.
Spring hanger travel verification
Walkdown verification of actual installed travel indicator position against design cold and hot positions. Mismatch often indicates installation error, support failure, or operating condition drift.
Spring hanger and expansion joint vendor drawing review
Where new spring hangers, expansion joints, or non-standard supports are being specified or replaced, we review vendor submittals against the CAESAR II load and travel envelope — before the hardware leaves the supplier.
When to Commission an Integrity Assessment
- After a flange leak, vibration incident, or support failure — to find the root cause and prevent recurrence
- Ahead of a turnaround or shutdown — to prioritise inspection and repair scope
- During a capacity revamp or debottlenecking — to verify retained piping against the new operating envelope
- After an equipment change-out — to reverify nozzle loads against new vendor data
- As part of an operational integrity audit or regulatory review
- After a process upset that exceeded the design envelope
Deliverables
- Findings register with severity ranking across all domains in scope
- Root-cause narrative for any observed failure
- Recommended remediation per finding — code-cited
- Isometric markups showing overstress and nozzle non-conformance
- Support register and spring hanger travel table
- Flange joint summary with gasket and bolt recommendations
- Executive summary for project management and reviewers
- FAQs
Frequently Asked Questions
Yes. Many operating plants have limited as-built documentation. We work from available P&IDs, isometrics (or walkdown data where drawings are missing), and operating history. Scope and cost scale with data quality.
Yes, where the assessment requires it — typically for spring hanger travel verification, support inspection, and failure investigation.
Yes. Most integrity engagements combine at least two of the four domains. A turnaround preparation scope often covers all four.
Both. Every finding includes a recommended remediation, code-cited, and implementable with piping hardware available in the market.
Yes. A single-joint flange leakage investigation is a common stand-alone scope — typically completed in one to two weeks depending on data quality.