COMPLIANCE INFO_2010-2011 - Laserfiche WebLink

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I NTIAL Crew members donned protective gear with full body coverage, face mask, and breathing apparatus. They also wore safety harnesses and set up a tripod with winch and cable for rescue operations, per OSHA safety requirements, and had a safety attendant stationed immediately outside the tank opening. We were, in fact, exceptionally impressed throughout the process with the safety consciousness of the crew members. The sand blasting of the tank continued throughout the afternoon of May 31, and continued for 2 1/2 hours on the morning of June 1. The blasting was conducted using Black Beauty Slag from La Cygne, Kansas. The weather conditions were warm and dry; the crew confirmed the acceptable relative humidity with the local weather bureau. The slag was then removed from the tank and the interior vacuumed. At the conclusion of the sand blasting, we observed that the interior had been cleaned to "white metal," and the anchor profile was spot checked to be 3.8 mil. At this point, the crew performed a visual inspection of the tank. It appeared to be in excellent condition, with no perforations or signs of pitting or corrosion damage. As a result, they decided that it was not necessary to conduct hammer tests or ultrasonic tests, a decision allowed by AN 1631. However, they did have a Cygnus ultrasonic wall thickness tester at the site, and demonstrated its operation for us on a portion of the tank. The particular model they used can provide readout to a printer, computer, or computer disk. The procedures demonstrated were judged to be proper. Given the lack of visible damage in the tank, there was no need to make repairs. Spraying of the lining material commenced at 1:00 PM on June 1,just a few hours after completion of the sand blasting. The product was sprayed at 105°F at a rate of 1, gallon per minute. Approximately 2 1/2 hours were required to complete the process. After this general lining, a striker plate was sprayed and installed. Then, a manway cover was sand blasted on both sides and coated with the lining materiaL The manway was covered to prevent foreign material from entering the tank. The fining was then allowed to cure oven-Light (longer than the 10- to 12-hour curing period stated by the manufacturer). The next morning the tank was purged and the lining inspected. The lining was tested for hardness with a Barcol hardness tester, and the thickness was measured with a Quanix 1500 film thickness gauge. A few areas were found with less than the required minimum of 100 mils; they were brush coated. A holiday detector was used to detect holidays, in accordance with API 1631. The model used a "coat-hanger" electrode, which the crew felt to be superior to the Silicone Brush or T-Tip electrodes recommended by the manufacturer, because it better defines the location of pin holes. Several pin holes were found and repaired. The tank was then closed in accordance with API 1631 recommendations. Figure 3 shows the cover plate bolted in place and sprayed over with the lining material. The MRt-App"MM-FR 6