What Is Surveillance?
Welding surveillance is the continuous on-site monitoring of the welding production process. Its difference from welding inspection is timing: inspection evaluates the result, whereas surveillance observes, while welding is taking place, that the process is being run correctly.
Why Is It Done?
The aim is to check, as they are applied, those aspects of welding that cannot be verified afterwards: preheat temperature, interpass temperature, welding sequence and storage of consumables.
Who Requests It?
- Buyers of pressure equipment and pipelines
- EPC contractors and project owners
- Steel structure and bridge projects
- Shipyard and marine structure projects
- Energy and petrochemical investors
Scope of Surveillance
- Validity of the welding procedure specification (WPS) and its qualification (WPQR)
- Scope conformity of welder and operator qualification certificates
- Assignment of welding coordination personnel
- Consumable type, batch traceability, and drying/storage conditions
- Joint preparation, cleanliness, and tack weld quality
- Measurement of preheat temperature
- Interpass temperature control
- Conformity of welding parameters (current, voltage, speed) with the WPS
- Post-weld heat treatment cycle records
- Welding sequence and distortion control
- Verification of NDT scope and timing
Related Standards
- ISO/IEC 17020
- ISO 3834 series
- ISO 14731
- ISO 9606 series
- ISO 15614 series
- EN ISO 5817
Method and Equipment
- Contact thermometer and thermal pen
- Welding parameter measurement device (current/voltage)
- Weld seam gauges
- Moisture meter (consumable storage conditions)
- Ferrite meter (for stainless steel welds)
- Photographic recording equipment
Surveillance Process
- 1Defining Scope and CriteriaThe order specification, the inspection and test plan (ITP), the delivery schedule and the reporting frequency are agreed with the buyer.
- 2Supplier AssessmentThe supplier's quality system, capacity, subcontractors and past performance are reviewed; a risk level is assigned.
- 3Surveillance PlanBased on the risk level, the frequency of site visits, the hold and witness points and the reporting calendar are planned.
- 4On-site SurveillanceThe surveyor attends the works during manufacturing, performing document checks, process observation and witnessing of inspections.
- 5Progress and Schedule MonitoringProgress against the plan is monitored; the risk of delay is identified early and reported to the buyer.
- 6Managing NonconformitiesDeviations found are reported, corrective action is requested and its close-out is followed up.
- 7Shipment Release and Close-outThe final inspection and the documentation package are checked; release for shipment is granted and a close-out report is issued.
Surveillance Report
- Details of the survey company, the surveyor and the buyer
- References to the order, the specification and the ITP
- Date of the visit and scope of the surveillance
- Findings of the document check
- Stage of manufacture and progress status
- Inspections and tests witnessed
- Nonconformities found and the status of corrective action
- Assessment of the schedule and the risk of delay
- Photographic records
- Recommendations for the next surveillance visit
- References of applied WPS and WPQR
- Welder qualification certificates and scope control
- Consumable batch and storage records
- Preheat and interpass temperature measurements
- Welding parameter observations
- Heat treatment records
- Nonconformities and corrective actions
Limits of the Report
Surveillance does not remove the supplier's responsibility and does not assume liability for the quality of manufacture. The surveyor reports what was observed during the periods spent on site; production during the periods of absence falls outside the report. A surveillance report is neither an acceptance statement nor a guarantee; the inspection and acceptance provisions of the contract remain in force.
Accreditation
Surveillance activities are carried out under ISO/IEC 17020, which requires the impartiality of the survey body, the competence of its personnel and the validity of the survey methods. The impartiality rule is decisive: a survey body may not be a party to the trade in, or the manufacture of, the goods it surveys. EUROLAB holds internationally recognised accreditation under ISO/IEC 17020, granted by accreditation bodies that are signatories to the ILAC mutual recognition arrangement; because accredited scope is defined per type of surveillance, it is confirmed in writing at the quotation stage.
Scope and authorisationsRelated Surveillance Services
Frequently Asked Questions
What is the difference between welding surveillance and weld inspection?
Inspection evaluates the result of a completed weld (visual, NDT). Surveillance, on the other hand, monitors the process while welding is taking place. Matters such as preheat temperature or whether the consumable was properly dried cannot be determined by looking at the finished weld seam; these can only be verified through surveillance.
Why is the scope of a welder's certificate checked?
A qualification certificate issued under ISO 9606 is not unlimited: it is valid based on material group, thickness range, pipe diameter, welding position and process. A welder performing a weld outside this scope is not authorized for that work, even with a valid certificate. In addition, the certificate's validity period and maintenance records are also checked.
Does surveillance reduce the supplier's responsibility?
No, it does not. The surveyor observes and reports on behalf of the buyer; the supplier remains responsible for the quality of manufacturing and compliance with the contract. A surveillance report is not a statement of acceptance.
Is the surveyor present on site continuously?
This depends on the level of surveillance. On critical projects, continuous (resident) surveillance is applied; on others, visits are made at specific hold points. Manufacturing carried out while the surveyor is not present falls outside the scope of the report, and this is clearly stated in the report.
How is the independence of the surveillance body ensured?
Surveillance is carried out under ISO/IEC 17020, which requires impartiality and the prevention of conflicts of interest. The surveillance body cannot be a party to the design or production of the manufacturing it surveys.