Brideau Energy Bulk Fuel Storage Tank Inspection

Previous



Next

CommTank Inc. provided tank cleaning and out-of-service inspections of two 50,000-gallon bulk fuel storage tanks at Brideau Energy’s storage facility in Templeton, Ma. These tanks had fixed cone roofs and no internal floating roofs.

Tank Cleaning

• Provided a written health and safety plan
• Provided confined space entry permits per D-129 CFR 1910.146
• Provided retrieval system, ventilation equipment, supplied air system, communication equipment, personal protective equipment (PPE), lighting, safety barriers, ladders, etc.
• Removed manways
• Removed and disposed of non-pumpable tank bottoms
• Purged gases from the tanks and tested for flammable vapors in accordance with NFPA and all other applicable regulations
• Performed pre-entry testing
• Entered tanks and cleaned inner tank bottoms with absorption pads to remove residual fluids
• Re-installed manways, complete with new seals 

Perform AST Inspections According To API 653

• Magnetic Flux Leakage (MFL) scanning of the tank bottoms for the detection of underside or internal corrosion with indications confirmed with ultrasonic testing (UT) and pit gauging.
• Visual Inspection (VT) of the bottom plate butt welds, internal and external shell-to-bottom welds and the bottom-to-sump and sump welds.
• Ultrasonic testing of the critical zones with a 12-inch (circumferentially) by 6-inch (towards tank center) scrub at each settlement survey location.  These areas are to be noted on the bottom layout and include minimum and average.  If recordable corrosion is detected, notify client immediately. 
• Ultrasonic testing of the tank bottoms with one (1) reading per plate.
• Inspection of the sumps to include visual of all welds and ultrasonic testing of the sides and bottoms.
• Ultrasonic testing of the tank shells with ten (10) readings per course up the spiral stairway.
• Ultrasonic testing of the fixed tank roofs with three (3) readings per plate.
• Ultrasonic testing of the nozzle necks with four (4) readings each (12, 3, 6, and 9 o’clock).
• Ultrasonic testing of the repads, flanges and covers, if present, with one (1) reading, each.
• Settlement measurements and evaluations of bottom settlement per API Standard 653, Annex B. 
• 11.    Visual inspection and engineering evaluations per API Standard 653. This included a direct visual inspection of all accessible first course and nozzle welds.

API 653 Post-inspection Report

CommTank provided written outcome reports that included the following information:

• A summary of the inspection findings and repair recommendations
• Applicable inspection checklists per API 653 guidance
• Foundation settlement evaluations
• Safe fill height and safe fill height versus specific gravity evaluations
• CAD drawings illustrating bottoms, roofs, and shell layouts with locations of significant findings
• NDT data with applicable data tables including locations and remaining thicknesses of any recordable internal or underside bottom metal losses
• Photographs

API 653 Inspection Personnel 

The crew consisted of an Inspector certified per API Standard 653 / NDT Crew Supervisor and a safety attendant. 

About the Author: Dan Hoag

Dan Hoag has worked in the environmental and tank storage industry for 16 years. Dan’s range of expertise includes designing systems for oil spill clean-ups, treating soil contamination through "in situ" oxidation and testing, and inspecting underground storage tank systems. As head of Marketing and Information Technologies at CommTank, Dan draws from field experience to write about fuel, water and chemical storage technologies, and the regulations that affect them. He has developed training courses in home inspection, underground storage tank operator, ultrasonic thickness and tank tightness testing. Over the past decade, Dan has published over 60 articles about industry trends and has documented commercial, residential, and environmental projects through illustration, videos, and photography. When Dan unplugs from technology, he spends his time backyard farming, hiking, and kayaking, while masquerading as a hockey player during the wee hours of the morning.