Storage Tank Welding & Coating Inspection
Third-party welding and protective coating inspection for aboveground storage tank fabrication, erection, repair and maintenance projects.
Storage tanks combine large welded structures with internal and external surfaces that may require controlled corrosion protection.
Dilenza provides qualified welding and coating inspectors for storage tank projects at fabrication facilities, construction sites, terminals and other industrial locations worldwide.
Inspector profiles are selected according to the tank type, project phase, applicable standards, materials, coating system, location and required assignment duration.
Inspection for Storage Tank Projects
Storage tank inspection requirements change according to whether the project involves new fabrication, field erection, repair, modification or coating work.
Dilenza can support:
- Welding inspection
- Protective coating inspection
- Third-party inspection
- Tank fabrication inspection
- Tank erection inspection
- Repair inspection
- Vendor inspection
- Resident inspection
- Shutdown or maintenance support
Storage Tank Welding Inspection
Weld quality develops throughout the fabrication and erection process.
Depending on the project, Dilenza welding inspectors may support:
- Material identification
- Material traceability
- WPS verification
- PQR review
- Welder qualification verification
- Joint preparation
- Fit-up inspection
- Welding surveillance
- Preheat and interpass monitoring
- Welding parameter verification
- Visual welding inspection
- NDT witnessing
- Vacuum-box testing witnessing where applicable
- Weld repair follow-up
- Dimensional inspection
- Hydrostatic-test witnessing
- Final documentation review
Storage Tank Coating & Lining Inspection
Protective coating and lining systems can be important for both external corrosion protection and internal service conditions.
Dilenza coating inspectors can support:
- Tank shells
- Roofs
- External steelwork
- Internal tank surfaces
- Tank bottoms
- Structural attachments
- Platforms and access steelwork
- Other project-specific coated surfaces
Typical Coating Inspection Activities
Depending on the project:
- Coating specification review
- Surface-condition assessment
- Surface preparation
- Surface cleanliness
- Surface-profile measurement
- Dust and contamination checks
- Environmental-condition monitoring
- Dew-point measurement
- Relative-humidity monitoring
- Steel-temperature checks
- Coating-material verification
- Application surveillance
- Stripe-coat inspection
- Wet-film thickness
- Dry-film thickness
- Holiday testing
- Adhesion testing
- Repair inspection
- Final coating documentation
Third-Party Storage Tank Inspection
Dilenza can provide independent welding and coating inspectors for:
- Tank owners
- EPC organizations
- Contractors
- Tank fabricators
- Equipment suppliers
- Terminal operators
- Project quality teams
Inspection can be aligned with:
- Inspection and Test Plans
- Hold points
- Witness points
- Project specifications
- Approved procedures
- Client requirements
- Reporting requirements
Tank Components We Can Support
Tank Shells
Welding inspection for shell courses, vertical seams and circumferential joints.
Tank Bottoms
Inspection of bottom plates, annular plates, welded joints and project-specific lining or coating requirements.
Tank Roofs
Inspection of fabricated and erected roof components and associated welds.
Nozzles & Attachments
Inspection of nozzle connections, reinforcement details and welded attachments.
Internal Surfaces
Coating or lining inspection according to the project system and service requirements.
External Surfaces
Protective coating inspection for tank shells, roofs and associated structural steel.
API 650 Tank Welding Inspection
API 650 is a key standard for new welded aboveground storage tank projects.
It establishes requirements covering materials, fabrication, erection and inspection of applicable vertical cylindrical welded tanks.
Where API 650 applies, inspection may involve:
- Material verification
- Welding procedure requirements
- Welder qualifications
- Shell fabrication
- Bottom fabrication
- Roof fabrication
- Joint fit-up
- Welding surveillance
- Weld examination
- Repairs
- Dimensional checks
- Hydrostatic testing
- Final documentation
The applicable edition, project-specific requirements and inspector responsibilities must always be established from controlled project documentation.
API 653 Repair & Existing Tank Projects
Existing aboveground tanks may require inspection support during repair, modification or reconstruction work.
API 653 is specifically associated with tank inspection, repair, alteration and reconstruction.
Depending on the project, Dilenza welding or coating inspectors may support:
- Weld repairs
- Plate replacement
- Bottom replacement
- Nozzle modifications
- Structural repairs
- Repair welding
- NDT witnessing
- Reinspection
- Coating repairs
- Lining repairs
- Final documentation
Where API 653-certified inspection is specifically required, that qualification must be clearly established as part of the inspector requirement before selection.
Inspection Before, During & After Welding
Before Welding
- Material verification
- Traceability
- WPS review
- Welder qualifications
- Joint preparation
- Fit-up
- Alignment
- Welding consumables
- ITP requirements
During Welding
- Welding process
- Welding parameters
- Preheat
- Interpass temperature
- Consumable handling
- Workmanship
- Production surveillance
After Welding
- Visual inspection
- NDT status
- Repairs
- Reinspection
- Dimensional checks
- Testing
- Documentation
Coating Inspection from Surface Preparation to Final Verification
Surface Preparation
Inspection may include:
- Substrate condition
- Surface cleanliness
- Abrasive blasting
- Surface profile
- Dust and contamination
- Environmental conditions
Coating Application
Inspection may include:
- Coating material verification
- Mixing
- Application conditions
- Stripe coating
- Wet-film thickness
- Recoat intervals
Final Verification
Inspection may include:
- Dry-film thickness
- Holiday testing
- Adhesion testing where required
- Repairs
- Final visual condition
- Documentation
Storage Tank Standards & Project Requirements
Depending on the project, requirements may include:
API 650
New welded aboveground storage tank fabrication and erection.
API 653
Inspection, repair, alteration and reconstruction of existing aboveground storage tanks.
API 620
Large welded low-pressure storage tanks where applicable.
Protective Coating Requirements
These may originate from:
- AMPP standards
- ISO standards
- API recommendations
- Client specifications
- Coating manufacturer requirements
- Project coating specifications
API also maintains dedicated aboveground storage tank standards covering tank construction, inspection, repair, cathodic protection and tank-bottom linings.
Selecting a Storage Tank Inspector
Certification alone does not define suitability.
Dilenza considers:
- Welding or coating discipline
- Tank fabrication experience
- Tank erection experience
- Repair experience
- API 650 familiarity
- API 653 qualification where specifically required
- Materials
- Welding processes
- Coating or lining systems
- Project phase
- Location
- Language
- Availability
- Assignment duration
Welding Profiles
Depending on the requirement:
- AWS CWI
- CSWIP
- International Welding Inspector
- Relevant NDT qualifications
- API 653 where specifically required
- Other project-specific credentials
Coating Profiles
Depending on the requirement:
- AMPP coating inspection qualifications
- FROSIO qualifications
- Other project-specific coating credentials
Review the Inspector Before Deployment
Relevant storage tank inspector profiles can be presented for client technical assessment before confirmation.
The client can review:
- Qualifications
- Tank project experience
- API experience
- Welding or coating background
- Coating/lining experience
- Reporting capability
- Location
- Availability
Where required, interviews with shortlisted inspectors can be arranged before final selection.
Inspection Coverage Built Around the Tank Project
Single Inspection Visit
One defined hold point, witness point or inspection activity.
Recurring Inspection
Visits aligned with fabrication or erection stages.
Resident Inspector
Continuous inspection during extended tank construction or repair work.
Shutdown / Maintenance Support
Temporary resources during repair, refurbishment or coating projects.
Multi-Site Inspection
Inspection across fabrication suppliers and final project locations.
Inspection Reporting
Depending on the assignment, reporting can include:
- Daily reports
- Inspection visit reports
- Photographs
- ITP status
- Material status
- Welding observations
- NDT status
- Repair follow-up
- Coating observations
- Environmental readings
- DFT records
- Holiday-test status
- Hydrotest status
- Punch lists
- Final summaries
Frequently Asked Questions
Does Dilenza provide both welding and coating inspectors for storage tanks?
Yes. Support can cover welding, coatings, linings or both disciplines according to the project.
Can Dilenza provide API 650-experienced welding inspectors?
Yes. Where API 650 applies, relevant tank fabrication and standards experience can be considered during inspector selection.
Can Dilenza support API 653 repair projects?
Yes, subject to the project scope and required qualifications. Where API 653 certification is specifically required, that requirement should be identified during inspector selection.
Can Dilenza inspect storage tank coatings and linings?
Yes. Coating inspectors can support surface preparation, environmental conditions, coating application, DFT, holiday testing, repairs and documentation.
Can inspectors witness hydrostatic testing?
Yes, where hydrotest witnessing forms part of the agreed inspection scope.
Can Dilenza provide resident tank inspectors?
Yes. Resident inspectors can support long-duration fabrication, erection or repair projects.
Can we interview inspectors before deployment?
Yes. Relevant profiles can be reviewed and shortlisted inspectors can be interviewed where required.
Request a Storage Tank Inspector
Tell us:
- Project location
- Tank type
- New tank or existing tank
- Fabrication, erection or repair
- Welding, coating or both
- Applicable standard
- Required qualification
- Coating or lining system where applicable
- Start date
- Working schedule
- Expected duration
Dilenza will review the requirement and identify relevant inspector profiles.
Review Qualified Storage Tank Inspectors Before You Decide
The right inspector should fit the tank type, applicable standard, project phase and schedule—not simply hold an available certification.
Receive profiles matched to your project, review their relevant tank fabrication, erection or repair experience and, where required, interview shortlisted inspectors before confirming the assignment.
Welding & Coating Inspection for Storage Tank Projects
From one tank fabrication hold point to continuous inspection during erection, repair or coating work, Dilenza provides welding and coating inspectors selected around the technical requirements, project location and duration.