RDVI™ Technology Applied to Floating Roof Tanks
By: Ron Kessler, RDVI Business Development North America, Quest Integrity Group
Internal floating roofs (IFR) are utilized to control emissions of regulated material and require routine inspections as mandated by the Code of Federal Regulations 40 CFR 65.43. Annually, owner/operators are required to perform visual inspections for IFR Type A failures. IFR Type A failures may be classified as gross discontinuities of the floating roof or seal. These inspections are conducted from the manways and do not require tank entry.
Detection of IFR Type B failures require more intrusive inspections at a minimum of once every 10 years, as well as any time the vessel is emptied. IFR Type B failures include:
- Holes, tears or other openings in secondary seal or seal fabric.
- Gaskets no longer close off the product from atmosphere.
- Slotted membrane with more than10-percent open area.
Historically, inspections for IFR Type B failures required a manned entry into the vessel. A confined space entry of this nature
required extensive planning and must be supported with product transfer, supplied air and an extensive lockout/tagout effort.
Working in tandem with industry personnel, Quest Integrity Group has recently developed a robust strategy for this inspection requirement utilizing Remote Digital Video Inspection (RDVI™) technology. This methodology may be immediately deployed to single seal floating roof tanks.
RDVI is the newest advanced inspection service offering from Quest Integrity Group. RDVI enables visual inspection of nearly every plant system and component without confined space entry or costly disassembly. This inspection method utilizes highly skilled and experienced remote digital video inspectors, deploying a wide array of video borescopes, remote operated cameras, robotic crawlers and specialized tooling to deliver clear concise visual data. All RDVI activities are supported with comprehensive detailed reports that include all pertinent data points and images to document asset health.
The benefits of this inspection method are immense. The successful deployment of RDVI technology eliminates the need for confined space entry and lessens the risk profile associated with this inspection. Costs associated with emergency rescue teams, supplied air and less efficient use of plant inspection personnel are alleviated. There is also less disruption to plant operations because product does not need to be transferred and the tank may be left in service. Less planning and permitting is required, resulting in significant efficiencies. Another distinct advantage is improved documentation. Each inspection is captured on video and digital image, providing views previously only seen by the inspector entering the confined space.
In summary, RDVI is a minimally evasive visual inspection technique that may be safely deployed to inspect for IFR Type B failures on single seal tanks. This method is cost effective and capable of providing enhanced inspection deliverables, while evading the need for confined space entry. Used in conjunction with preventative maintenance programs and other nondestructive testing methodologies, RDVI supports safe and efficient plant operations and increased uptime.