Severe corrosion had caused pitting with some penetrations through the roof reducing the integrity of the refuge. refuge had to withstand a blast load of 0.25 bar. As this is an active gas storage unit welding was not an option for repairs. Application was carried out in accordance with a modified Belzona Know-How System GSS-9. A slurry mix of Belzona 4111 was used to bed steel doubler plates to cover the roof of the refuge. Penetrations through the roof were initially sealed with small plates bonded in place with Belzona 1211. A fire protection coating was finally applied to provide the required fire rating.
All safety factors were considered during the design of this repair which was carried out without the need for hot work. Access to several areas of the roof were limited to 500mm head room, so ease of application of the Belzona system was very important.