How to Select a Qualified PAUT Inspection Company
Selecting a PAUT inspection company should not be based only on the availability of equipment or the lowest commercial quotation.
Reliable Phased Array Ultrasonic Testing requires qualified personnel, suitable probes and wedges, validated procedures, weld-specific scan plans, representative calibration blocks, controlled data acquisition and competent technical review.
The selected company should demonstrate that it can inspect the actual component—not merely that it owns a PAUT instrument.
1. Confirm Personnel Qualifications
The inspection company should provide personnel qualified according to the project specification and employer’s written practice.
The project may require:
➤ PAUT Level II technicians
➤ TOFD-qualified technicians
➤ Ultrasonic Testing Level II certification
➤ PAUT or UT Level III technical support
➤ PCN, ISO 9712, ASNT or employer-based certification
➤ Relevant industry experience
➤ Valid vision-test records
➤ Site-safety training
➤ Client-specific approval
The qualification should cover the method and responsibilities assigned to the technician.
A conventional UT qualification alone should not automatically be treated as sufficient evidence of PAUT competency.
2. Review Practical Experience
Certification confirms that a person has met defined qualification requirements. It does not establish experience with every component and application.
Review the company’s experience with:
➤ Process-piping welds
➤ Pipeline girth welds
➤ Pressure vessels
➤ Small-diameter pipes
➤ Heavy-wall components
➤ Nozzle and branch connections
➤ Austenitic welds
➤ Dissimilar-metal welds
➤ Plant shutdowns
➤ Encoded inspection
➤ PAUT and TOFD data analysis
Experience should be relevant to the proposed project, material and weld geometry.
3. Evaluate Technical Capability
A qualified PAUT company should review the application before submitting a final technical commitment.
The review should consider:
➤ Material specification
➤ Outside diameter
➤ Wall thickness
➤ Weld preparation
➤ Expected defect types
➤ Available scanning surface
➤ Component temperature
➤ Applicable code
➤ Acceptance criteria
➤ Reporting requirements
If complete weld coverage cannot be achieved, the company should clearly explain the limitation and recommend supplementary inspection where necessary.
4. Verify PAUT Equipment
The inspection system should be suitable for the application and maintained in serviceable condition.
Important equipment details include:
➤ Manufacturer and model
➤ PAUT channel configuration
➤ Number of active elements
➤ Data-recording capability
➤ Encoder compatibility
➤ Software version
➤ Calibration status
➤ Battery capacity
➤ Availability of backup equipment
➤ Data-analysis capability
The newest or most expensive equipment does not automatically provide the best inspection. The complete setup must be appropriate for the component.
5. Check Probe and Wedge Availability
A PAUT instrument alone cannot inspect every weld.
➤ Small-footprint probes
➤ Standard weld-inspection probes
➤ Low-frequency probes
➤ High-frequency probes
➤ Dual-matrix probes
➤ Flat wedges
➤ Contoured pipe wedges
➤ Inside- and outside-diameter wedges
➤ TOFD probes and wedges
➤ High-temperature accessories
➤ Customized wedges
Probe frequency, aperture, pitch and wedge geometry should suit the material, thickness, curvature and expected defect orientation.
6. Confirm Scanner and Encoder Capability
Encoded inspection requires a scanner capable of maintaining probe position and coupling.
Depending on the application, the company may require:
➤ Small-bore circumferential scanner
➤ Large-diameter pipeline scanner
➤ Chain scanner
➤ Magnetic-wheel scanner
➤ Corrosion-mapping scanner
➤ Manual position encoder
➤ Two-axis raster scanner
➤ Customized scanner frame
The scanner must physically fit between the weld and nearby obstructions.
7. Review the PAUT Procedure
The written procedure should define:
➤ Scope and limitations
➤ Applicable standards
➤ Personnel requirements
➤ Equipment configuration
➤ Probe and wedge selection
➤ Calibration requirements
➤ Focal-law parameters
➤ Scanning pattern
➤ Data-quality requirements
➤ Indication evaluation
➤ Sizing method
➤ Acceptance criteria
➤ Reporting requirements
The procedure should be approved by the responsible technical authority before production inspection.
8. Request a Weld-Specific Scan Plan
A scan plan demonstrates how the ultrasonic beams cover the required examination volume.
It should identify:
➤ Component geometry
➤ Weld preparation
➤ Probe positions
➤ Refracted angles
➤ Focal depths
➤ Beam paths
➤ Weld-root coverage
➤ Fusion-face coverage
➤ Heat-affected-zone coverage
➤ Near-surface and far-surface limitations
➤ Required scanning directions
A generic scan image should not be accepted for components with materially different diameters, thicknesses or weld configurations.
9. Verify Calibration-Block Suitability
The PAUT company should identify a suitable calibration or reference block before mobilization.
The block should represent relevant variables such as:
➤ Material
➤ Diameter
➤ Wall thickness
➤ Surface curvature
➤ Ultrasonic response
➤ Weld geometry, where required
➤ Code-defined reflectors
➤ Required inspection range
Complex or critical applications may require a customized calibration block or flawed validation specimen.
10. Confirm Technique Validation
For challenging applications, ask how the contractor will demonstrate inspection performance.
Validation may include:
➤ Reference-reflector detection
➤ Weld-volume coverage
➤ Near-surface assessment
➤ Far-surface assessment
➤ Length-sizing accuracy
➤ Through-wall sizing
➤ Scanner repeatability
➤ Signal-to-noise evaluation
➤ Blind performance demonstration
Technique validation is especially important for small-bore pipes, complex welds, austenitic materials and radiography-replacement projects.
11. Review Reporting Capability
A professional PAUT contractor should provide traceable inspection records.
The reporting system should connect:
➤ Component identification
➤ Weld number
➤ Inspection procedure
➤ Equipment setup
➤ Calibration file
➤ Encoded scan file
➤ Indication table
➤ Repair history
➤ Final result
➤ Technical review
Ask whether the client will receive original scan data in addition to the final PDF report.
12. Check Data-Analysis Resources
Data collection and data analysis are separate technical responsibilities.
Large projects may require:
➤ Dedicated analysts
➤ Shift-wise data review
➤ Level III support
➤ Independent verification
➤ Repair tracking
➤ Rapid preliminary reporting
➤ Final quality review
➤ Secure data backup
If data acquisition exceeds analysis capacity, inspection results and shutdown decisions may be delayed.
13. Assess Backup Arrangements
Critical and shutdown projects should have contingency arrangements for:
➤ PAUT instrument failure
➤ Probe damage
➤ Wedge wear
➤ Encoder malfunction
➤ Scanner breakdown
➤ Cable damage
➤ Battery failure
➤ Computer or data-storage issues
➤ Personnel replacement
Backup equipment should be technically compatible with the approved procedure.
14. Review Health, Safety and Site Readiness
The contractor should understand site requirements covering:
➤ Permit-to-work systems
➤ Work at height
➤ Confined spaces
➤ Hot surfaces
➤ Electrical safety
➤ Couplant management
➤ Night-shift work
➤ Simultaneous operations
➤ Manual handling
➤ Personal protective equipment
Although PAUT does not involve ionising radiation, normal industrial safety controls remain mandatory.
15. Compare Technical and Commercial Scope
PAUT quotations should be compared on an equal-scope basis.
Confirm whether the price includes:
➤ PAUT equipment
➤ Probes and wedges
➤ Scanners and encoders
➤ Calibration blocks
➤ Qualified personnel
➤ NDT assistants
➤ Level III support
➤ Procedure preparation
➤ Scan-plan preparation
➤ Mobilization
➤ Travel and accommodation
➤ Surface preparation
➤ Consumables
➤ Data analysis
➤ Reporting
➤ Repair-weld reinspection
➤ Raw-data submission
➤ Standby time
➤ Additional working days
A low inspection rate may exclude essential technical or logistical items.
Questions to Ask a PAUT Contractor
Before issuing a purchase order, ask:
1. Have you inspected this material and weld geometry before?
2. Can you demonstrate complete weld-volume coverage?
3. Which probe, wedge and scanner will be used?
4. Is a representative calibration block available?
5. Who will prepare and approve the procedure?
6. Who will analyse and review the data?
7. What personnel certification will be provided?
8. Will the examination be manual or encoded?
9. What inspection limitations do you expect?
10. What daily production can realistically be achieved?
11. What backup equipment will be available?
12. Will raw PAUT data be submitted?
13. How will repairs and rescans be tracked?
14. What information and facilities are required from the client?
Warning Signs
Clients should exercise caution when a contractor:
➤ Confirms feasibility without reviewing drawings
➤ Claims PAUT can inspect every weld geometry
➤ Cannot provide qualified personnel documents
➤ Does not prepare a scan plan
➤ Uses one standard setup for all diameters and thicknesses
➤ Cannot identify a suitable calibration block
➤ Refuses to explain inspection limitations
➤ Provides only screenshots without original scan files
➤ Has no backup equipment for critical work
➤ Quotes production rates without reviewing site access
➤ Treats every ultrasonic response as a defect
➤ Cannot identify the applicable acceptance criteria
PAUT Contractor Evaluation Checklist
| Evaluation area | Evidence to request |
| Personnel | Certificates, experience records and vision tests |
| Equipment | Model, serial number and calibration status |
| Probes and wedges | Technical details and diameter suitability |
| Scanner | Configuration and access requirements |
| Procedure | Approved PAUT/TOFD procedure |
| Scan plan | Weld-specific coverage drawing |
| Calibration block | Drawing, material and reflector details |
| Validation | Demonstration or qualification results |
| Reporting | Sample report and raw-data index |
| Quality control | Calibration and data-review process |
| Backup | Spare equipment and personnel arrangements |
| Safety | HSE documents and site competency records |
Why Choose IAIS India?
Integrity & Advanced Inspection Solutions India Private Limited offers an integrated PAUT service capability through the Benny Surya Venture group.
Our support can include:
➤ PAUT and TOFD inspection services
➤ Qualified PAUT personnel
➤ Level III technical review
➤ Small-bore and large-diameter weld inspection
➤ Manual and encoded scanning
➤ Pipeline and pressure-vessel inspection
➤ Shutdown and turnaround support
➤ Procedure and scan-plan preparation
➤ Customized calibration blocks
➤ Flawed validation specimens and mock-ups
➤ PAUT/TOFD wedges
➤ Scanners and encoders
➤ On-site data analysis
➤ Weld-wise inspection reporting
➤ Domestic and international mobilization
This integrated arrangement helps coordinate the complete inspection process—from feasibility review and accessory development to field inspection and final reporting.
Information Required for a PAUT Proposal
Please provide:
➤ Client and project name
➤ Site location
➤ Component description
➤ Material specification
➤ Diameter and wall thickness
➤ Weld-joint drawing
➤ Number or length of welds
➤ Applicable code
➤ Acceptance criteria
➤ Access conditions
➤ Surface-preparation status
➤ Inspection schedule
➤ Shift requirements
➤ Reporting format
➤ Raw-data requirements
➤ Client-provided facilities
Request a PAUT Technical and Commercial Proposal
Share the component drawings and inspection scope with our technical team. We will review feasibility, inspection coverage, equipment configuration, calibration requirements, personnel deployment and reporting deliverables before submitting our proposal.