Semfa offers a complete package of NDT and ANDT inspection techniques covering all aspects of testing to EEMUA 159 and API 653
Typical Scope of Work covering tank inspections is covered below but this can be the base line for additional inspections or techniques that specific clients will require. SEMFA works with clients in close co-operation to ensure that their requirements are met at all times
Typically report should include, but will not be limited to: -
- Foundation Assessment: Settlement, tilting, corrosion of annular, earthling strip etc.
- Tank Bottom: General corrosion, weld condition, buckling and ripples in plates.
- Tank Shell: Buckling, general plate condition welds or rivets nozzles and man ways, handrails and stairs, wind girders.
- Roof: Plate condition, roof supports, weld of roof-to-shell, nozzles, vents, handrails and stairways.
The tank floor will be inspected and typically consisting of the following:
- 100% MPI inspection of the annular plate to shell weld
- 100% vacuum box testing and inspection of all floor welds
- Floor Scan using the principles of Low Frequency Electromagnetic Technique (LFET) and to report all relevant detects both topside and underside greater than 20% wall loss. Provide ultrasonic thickness checks to areas where scanning is restricted. UT confirmation on all detects found & measured locations.
- Ultrasonic thickness checks on all floor plates — 5 readings per plate
- Ultrasonic Testing (UT) thickness scans on the complete circumference of the tank floor on the annular plate to shell area.
- UT thickness checks in and around the sump.
- Visual inspection of plates, welds, brackets, internal nozzles and pipe work etc.
The tank shell inspection will include the following:
- Ultrasonic thickness readings on the shell as specified and to comply with EEMUA/API continuous readings being taken.
- Ultrasonic thickness checks on shell bottom / first course, 5 per plate and compression wave UT scans of each vertical weld either side recording the minimum thickness or weld defects.
- Ultrasonic thickness cheeks on all accessible internal & external tank nozzles.
- Ultrasonic thickness checks every 500mm around the external lip, as close to the external lip edge as possible. Further to take measurements of the external lip outstand at each 500mm point.
- MPI all nozzle & manways internal welds
- Visual inspection of accessible plates, welds, brackets, handrail.
The tank roof inspection will include the following:
- Ultrasonic thickness cheeks on each roof plate — as per EEMUA 159/API 653.
- Ultrasonic readings on pipe work and nozzles as applicable/accessible.
- Visual inspection of plates, welds, brackets handrail etc.
Additional Inspection services and technologies
SEMFA can also offer
- “TankPac “inspection as a comprehensive system
- Tank mapping and profiling of sludge
- Pipeline leak detection and inspection using free flowing “Smartball” from Pure Technologies Inc. to test and investigate for leaks in oil, water and gas pipelines.
Use of crawlers internally and externally will ,in many cases, negate the use of scaffolding. Semfa can also offer rope access systems and training if required.