Tank Floating Roof Repairs

Overview

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.

Scope

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

Solution

  • Bespoke engineered composite repair solution for each defect type in accordance with ISO 24817 and meeting API 653 requirements
  • UHP water jetting to clean hydrocarbons from tanks roofs
  • Sponge Jet low dust blasting used to prepare the surfaces to a Sa2.5 profile
  • Technowrap 2K™ & DRS system
  • Vacuum bag consolidation to optimise material bond strength ratios
  • Multi-skilled technicians to provide entire solution with no production loss

Benefits

  • Repair reinstated original strength of tank roofs providing long term integrity (20 years design life)
  • Long term corrosion protection
  • Cold work application of lightweight, portable composite materials - no hot work & no heavy lifting or large steel components
  • 90 reduction in dust eliminated need for scaffold encapsulation
  • Multi-skilled small execution team reducing personnel & logistics costs
  • TechnowrapTM moves with the steel as one structural component
  • Works completed live with no disruption to tanks being consistently operated
  • Commitment to the client's safety processes ensured the job was completed safely with high productivity

IC Integrity

iasgroup is a partner in the IC Integrity JV, providing leading production critical cold work solutions that remove or minimise the need for shutdowns. The JV is home to market leading technologies such as TechnowrapTM and QuickflangeTM.