In-Service Tank Inspection
Taking a storage tank out of service is rarely straightforward. In-service inspections let you assess the condition of the asset while it stays operational.
About in-service inspection
Removing a storage tank from service can be a significant undertaking. On sites with limited storage capacity, a single tank going out of action can affect operations for weeks, and the demands of product transfer, cleaning and access preparation add both time and cost before inspection work even begins.
In-service inspection provides a practical means of assessing tank condition without taking the asset offline. Using external visual inspection, ultrasonic thickness measurement, external NDT and remote assessment, we evaluate the shell, roof, floor-to-shell region and associated components where accessible, collecting much of the same core data as an out-of-service inspection and supplying EEMUA 159 structural integrity calculations where applicable.
The floor plates are a major component that cannot be fully assessed while the tank is in service. Where low cycle fatigue is a potential damage mechanism, the floor-to-shell weld and outstand are examined using NDT techniques, and settlement surveys are carried out to check for planar tilt and differential settlement where required.
Inspection scope
In-service inspection is defined by the tank type, its service history and the anticipated degradation mechanisms. A typical scope includes:
- External visual inspection
- Ultrasonic thickness measurement
- Corrosion mapping
- Settlement assessment, including planar tilt and differential settlement
- Shell distortion assessment
- Floor-to-shell weld and outstand examination by NDT
- Roof and nozzle inspection
- Bund and associated pipework assessment
- Review of historical inspection data and corrosion rates
In-service and out-of-service, working together
Part of the EEMUA programme
EEMUA 159 defines both in-service and out-of-service intervals, and an in-service inspection by a qualified assessor contributes directly to meeting them.
Keeps assets available
Much of the same core data is gathered without taking the tank offline, avoiding weeks of lost storage capacity.
Works alongside outages
In-service inspection helps operators plan out-of-service work for when it is genuinely needed, rather than by the calendar alone.
Reporting and recommendations
Every in-service inspection produces a clear report that sets out the findings, the condition of the tank and the degradation mechanisms observed, with recommendations prioritised by risk.
Reports are written by the inspector who carried out the work. For tanks within the EEMUA 159 scope, an in-service inspection carried out by a qualified assessor contributes directly to the formal inspection programme, an important consideration for operations managing insurer and regulatory expectations.
Related inspection services
Need to inspect a tank without an outage?
Speak with our team about in-service inspection and how it fits your inspection programme.