Floating tank roofs are prone to integrity failure due to long service life times as well as ineffective water drainage and temperature differentials between upper and lower surfaces driving steel expansion and curving of roof plates.
IC Integrity was contracted to support a major operator with live tank floating roof repairs across three 18m high, 60m diameter tanks in South Australia. Previous patching techniques were used as temporary repairs, however an engineered long term integrity solution was required to meet regulations for uncontrolled hydrocarbon leaks.
IC Integrity delivered visual inspection, corrosion and coating survey and NDT mapping to fully assess the condition of each roof.
The tanks had the following specifications:
Structure | Hydrocarbon Floating Tank Roof |
Surface Preparation | Sa 2.5 |
Design Pressure | 28 kPa |
Design Temperature | 700C |
Application Temperature | 200C |
Design Life | 20 years |
Total Repair Area | 115m2 |
Geometry | Varying roof geometries |
Corrosion Type | External |
Defect Details | 25 repairs including various through-wall defects up to 400mm, weld seam cracks of various lengths and light, medium and heavy corrosion |