Vendor Inspection Services
Buying industrial equipment from a supplier?
Dilenza provides independent vendor inspection services during manufacturing, fabrication, assembly and testing—helping project teams verify requirements before equipment leaves the supplier.
From one critical witness point to recurring manufacturing surveillance or final FAT, we match inspectors according to the equipment, technical scope, required qualifications, supplier location and project schedule.
Inspection can follow your:
- ITP
- Purchase Order
- Technical Specification
- Drawings
- Approved Procedures
- Project Standards
ITP · PO · Specification · Drawings accepted
Manufacturing journey
Materials
Review
Fabrication
Witness
Assembly
Hold
Testing
Monitor
Release
Verify
- Single Visit
- Recurring
- Resident
- Multi-Site
Find Problems While They Can Still Be Corrected
Industrial equipment can pass through many manufacturing stages before reaching the project site.
Once fabrication is complete, internal areas may become inaccessible.
Once equipment is painted, assembled, packed or shipped, correcting a problem becomes more difficult.
Vendor inspection provides independent technical visibility while manufacturing is still taking place.
It can help your team verify:
- Project-defined inspection points
- Materials and traceability
- Manufacturing progress
- Fabrication quality
- Welding activities
- Dimensions
- Mechanical assembly
- NDT status
- Testing
- Documentation
- Coating status
- Packing and preservation
- Outstanding non-conformities
Inspect at the supplier. Resolve issues before they become site problems.
Inspection Follows the Manufacturing Process
- 01
Documentation
- ITP
- Drawings
- Specifications
- Procedures
- 02
Materials
- Certificates
- Identification
- Traceability
- 03
Manufacturing
- Fabrication
- Welding
- Machining
- Assembly
- 04
Inspection Points
- Hold
- Witness
- Review
- Surveillance
- 05
Testing
- NDT
- Pressure Tests
- Functional Tests
- FAT
- 06
Final Verification
- Documentation
- Marking
- Preservation
- Packing
- Release Status
The exact sequence depends on the equipment and approved project documentation.
Hold Points, Witness Points and Manufacturing Milestones
Vendor inspection should not be a generic factory visit.
For many industrial projects, the Inspection and Test Plan (ITP) defines where independent inspection is required throughout manufacturing.
Depending on the approved ITP, Dilenza inspectors can attend:
Hold Points
Defined stages where work should not proceed until the required inspection or authorization has taken place according to the project arrangements.
Witness Points
Activities where the nominated party is given the opportunity to attend and witness a defined manufacturing or testing activity.
Review Points
Project-defined documentation or records reviewed as part of the inspection scope.
Surveillance
Independent attendance during manufacturing to observe specified production or quality activities.
The inspector follows the controlled project requirements and assigned responsibilities, rather than creating acceptance criteria at the supplier.
What Can a Vendor Inspector Check?
The scope depends on what is being manufactured. Typical vendor inspection activities can include:
Documentation
- Approved drawings
- Inspection and Test Plan
- Manufacturing procedures
- Material certificates
- Welding documentation
- NDT records
- Calibration records
- Test procedures
- Previous inspection findings
- Manufacturing data book status
Materials & Traceability
- Material identification
- Material certificates
- Heat or batch identification
- Traceability
- Project-required markings
- PMI status where specified
Manufacturing & Fabrication
- Manufacturing progress
- Workmanship
- Fabrication condition
- Fit-up
- Welding status
- Dimensions
- Machining
- Mechanical assembly
- Interfaces between components
Where specialist welding inspection is required, an appropriately qualified welding inspector can be selected.
NDT
- VT
- PT
- MT
- UT
- RT
- Other Specified Methods
Where defined by the project. The vendor inspector may witness activities or verify NDT status according to the assigned responsibilities. NDT execution should be carried out by appropriately qualified personnel where required.
Testing
- Pressure Testing
- Hydrostatic Testing
- Functional Testing
- Performance Testing
- Load Testing
- Electrical or Mechanical Tests
The exact test and acceptance criteria must come from the applicable project documentation.
Coating & Surface Protection
- Surface Condition
- Coating Status
- DFT Records
- Preservation
- Repair Status
Projects requiring specialist coating inspection can be matched with qualified AMPP, FROSIO or other specified coating inspectors.
Final Verification
- Visual condition
- Equipment completeness
- Nameplates and markings
- Outstanding punch items
- Documentation status
- Preservation
- Packing
- Shipping marks
- Project-defined release status
Before shipment or project-defined release.
Inspect at the supplier. Resolve issues before they become site problems.
Factory Acceptance Test Inspection
For many engineered equipment packages, the Factory Acceptance Test (FAT) is one of the final opportunities to verify equipment before shipment.
Dilenza can provide vendor inspectors for FAT attendance according to the approved test procedure and project requirements.
Depending on the equipment, FAT witnessing may involve:
- Functional Tests
- Performance Tests
- Pressure Tests
- Mechanical Operation
- Instrumentation Checks
- Safety Functions
- Project-Specific Testing
The inspector can document:
- Activities Witnessed
- Test Results
- Deviations
- Open Points
- Photographic Evidence
- Final Status
The inspector witnesses against the agreed test procedure—not an assumed checklist.
Industrial Equipment We Inspect at Suppliers
Vendor inspection is most effective when the inspector understands the actual equipment.
Pressure Equipment & Piping
- Pressure Vessels
- Heat Exchangers
- Columns
- Boilers
- Tanks
- Piping
- Valves
- Skids
Inspection can support materials, fabrication, welding, NDT, dimensional verification, pressure testing and documentation.
Industrial Machinery
- Pumps
- Compressors
- Turbines
- Mechanical Equipment
- Production Machinery
- Engineered Assemblies
Inspection can support manufacturing, assembly, dimensional verification, functional testing and FAT.
Structural Steel & Heavy Fabrication
- Frames
- Modules
- Platforms
- Pipe Racks
- Support Structures
- Heavy Welded Assemblies
Inspection can support material traceability, fit-up, welding, NDT, dimensions and final fabrication status.
Shipbuilding & Marine Equipment
- Vessel Structures
- Marine Equipment
- Piping
- Machinery
- Offshore Modules
Inspector selection can consider relevant shipbuilding, marine fabrication, welding or coating experience.
Energy Equipment
- Power Equipment
- Mechanical Packages
- Fabricated Systems
- Renewable-Energy Components
Inspection can cover one manufacturing milestone or follow equipment through several production stages.
Oil, Gas & Process Equipment
- Piping
- Pressure Systems
- Tanks
- Skids
- Mechanical Packages
- Fabricated Equipment
Inspection can be aligned with project-defined manufacturing and testing requirements.
Equipment First. Inspector Second.
A vendor inspector is not a generic profile.
An inspector experienced with pressure vessels may not be the right choice for rotating machinery.
A mechanical inspector may not be qualified to perform the welding responsibilities defined by your ITP.
A coating specialist may be required for a complex protective coating program.
Dilenza therefore reviews the project before selecting the profile.
- 01
You Send
Location · Equipment · ITP · Scope · Standards · Dates
- 02
We Define the Profile
Discipline · Qualification · Equipment Experience · Industry Experience
- 03
We Match
Technical Fit · Location · Availability · Duration
- 04
You Review
Relevant inspector profiles can be submitted for technical assessment where appropriate.
- 05
Inspection
The confirmed inspector attends according to the agreed project scope.
One Supplier Visit or Full Manufacturing Visibility?
Choose the inspection model that best matches your manufacturing schedule, inspection frequency and required level of supplier oversight.
Match Inspection Frequency to Project Risk
Not every equipment package needs continuous inspection.
Single Visit
Suitable for: One Hold Point · Test · FAT · Repair Verification · Final Inspection
Recurring Vendor Inspection
Suitable when important inspection activities occur across several manufacturing stages. A recurring inspector can maintain visibility over progress, previous findings, repairs, ITP status, testing and documentation.
Resident Vendor Inspection
For major equipment packages or manufacturing programs requiring frequent or continuous technical presence.
Rotational Inspection
Structured technical coverage for longer manufacturing programs.
Multi-Site Vendor Inspection
One project may include pressure equipment from Italy, machinery from Germany, fabrication from China and marine equipment from South Korea. Dilenza can coordinate technical inspection across several manufacturing locations.
Client-Specific Vendor Inspection Requirements
Some projects define inspector requirements through client-specific qualification, designation or approval frameworks. Dilenza reviews these requirements against the controlled project documents before proposing profiles.
Saudi Aramco QM Inspection
Project-specific inspection support for supplier manufacturing, fabrication, testing and defined inspection activities where a Saudi Aramco QM requirement forms part of the assignment.
Know What Happened at the Supplier
A useful vendor inspection report should make the technical status understandable to a project team that was not present at the factory.
- Supplier and inspection location
- Equipment inspected
- Manufacturing progress
- Activities witnessed
- ITP reference
- Documents reviewed
- Measurements
- Test results
- Photographic evidence
- Deviations
- Non-conformities
- Repairs
- Outstanding points
- Previous finding status
- Inspector observations
- Project-defined hold or release status
What was inspected? What was found? What remains open?
Inspection Against the Project Requirements
Industrial suppliers manufacture equipment for projects using many different technical standards.
- ASME
- AWS
- API
- ISO
- EN
- Client Specifications
- EPC Specifications
- Classification Requirements
- Manufacturer Procedures
Dilenza does not assume which code applies.
- Standard
- Edition
- Acceptance Criteria
- Inspection Point
- Inspector Responsibility
must come from the controlled project documentation.
Clear Scope. Clear Responsibility.
Dilenza's vendor inspection service represents the purchaser's agreed technical inspection requirement at the supplier.
The inspector works against the scope provided for the assignment.
Vendor inspection should not automatically be treated as a substitute for:
- Statutory Inspection
- Notified-Body Activity
- Authorized Inspection
- Mandatory Certification
- Legally Required Conformity Assessment
Where an authorized or regulatory function is required, that requirement should be identified separately. This distinction helps keep the independent purchaser inspection scope clear.
Vendor Inspection Where Your Equipment Is Manufactured
Industrial projects increasingly depend on suppliers across several countries. Dilenza can review vendor inspection requirements throughout major manufacturing regions in:
The supplier determines the location. The equipment and inspection scope determine the profile.
Vendor Inspection Built Around the Equipment
Technical Profile Matching
We select according to the actual equipment and assigned inspection responsibilities.
Qualification Review
Where specific credentials are required, they form part of inspector selection.
Flexible Attendance
Attendance can cover a single witness point or months of supplier surveillance.
Profile Review
Relevant CVs and qualifications can be submitted before confirmation where appropriate.
Specialist Support
Welding, coating and other specialist profiles can be introduced where the scope requires them.
Global Manufacturing Coverage
Inspection can be coordinated across suppliers in multiple countries.
Request Vendor Inspection
You do not need a perfectly prepared enquiry. Start with what you already have.
- 01
Supplier
Country · City · Factory
- 02
Equipment
What is being manufactured?
- 03
Inspection Point
Hold · Witness · FAT · Surveillance · Final Inspection · Not Sure
- 04
Technical Requirements
Required inspector qualification or discipline, if specified.
- 05
Schedule
Date · Duration · Frequency
- 06
Documents
ITP · PO · Specification · Drawings · Test Procedure
Have only the supplier location and ITP? Start with those.
Vendor Inspection FAQ
What is vendor inspection?
Vendor inspection is independent technical inspection carried out at a supplier or manufacturer's facility to verify project-defined requirements during manufacturing, fabrication, assembly or testing.
What is the difference between vendor inspection and a factory audit?
A factory audit normally assesses the supplier's systems, capabilities or processes. Vendor inspection focuses on specific equipment or manufacturing activities being performed for a project.
What is vendor surveillance?
Vendor surveillance is repeated or ongoing technical attendance during manufacturing rather than inspection at only one final stage.
Can Dilenza follow our ITP?
Yes. Inspection can be structured around the client's approved Inspection and Test Plan and assigned hold, witness, review or surveillance points.
Can Dilenza attend a hold point?
Yes, where attendance at the hold point forms part of the agreed inspection scope.
Can Dilenza witness FAT?
Yes. Vendor inspectors can attend defined Factory Acceptance Test activities according to the approved test procedure and project requirements.
Can the inspector check material certificates?
Where material-document review forms part of the agreed scope, relevant certificates, identification and traceability can be verified against the project requirements.
Can the inspector check welding?
Yes, but specialist welding responsibilities should be assigned to an appropriately qualified welding inspector where required by the project.
Can the inspector check protective coatings?
General coating status may form part of a vendor inspection. Where specialist protective coating inspection is required, Dilenza can match appropriately qualified coating inspectors.
Can Dilenza provide vendor inspectors for pressure equipment?
Yes. Inspector profiles can be matched to pressure vessels, heat exchangers, piping, tanks, valves, skids and other pressure or process equipment.
Can Dilenza inspect machinery?
Yes. Machinery and mechanical-equipment inspection can support manufacturing, assembly, dimensional verification, functional testing and FAT according to the scope.
Can an inspector attend for only one day?
Yes. Single visits can support a specific hold point, witness point, test, FAT or final inspection.
Can Dilenza provide recurring vendor surveillance?
Yes. Recurring visits can be arranged throughout manufacturing according to project milestones or an agreed frequency.
Can Dilenza provide a resident vendor inspector?
Yes. Resident inspection can provide frequent or continuous supplier presence for longer manufacturing programs.
Can Dilenza inspect several suppliers for one project?
Yes. Multi-site inspection can coordinate technical coverage across several suppliers and manufacturing countries.
Can we review the inspector's CV before deployment?
Where appropriate, relevant CVs, qualifications and equipment experience can be submitted for client technical review before confirmation.
Does the vendor inspector approve equipment for shipment?
Only where that authority is explicitly defined by the project. The inspector reports according to the assigned responsibilities and should not assume purchaser, statutory or certification authority.
Equipment Being Manufactured at a Supplier?
Send us the requirement.
- Where?
- Supplier · City · Country
- What?
- Equipment or Package
- Which Stage?
- Manufacturing · Hold Point · Witness Point · Testing · FAT · Final Inspection
- Which Requirements?
- ITP · Specification · Standard · Required Qualification
- When?
- Date · Duration · Frequency
- Upload
- ITP · PO · Drawings · Specification · Test Procedure
Not sure which inspector profile is required? Send us the equipment and available project documentation. We can review the technical requirement before profiles are considered.
See What Is Happening Before the Equipment Leaves the Supplier.
Independent vendor inspection matched to the equipment, manufacturing stage and project requirements.