COMPLIANCE INFO_1986-2002 - Laserfiche WebLink

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After it is determined that a safe atmosphere has been established, the tank may be opened. If cutting and drilling are necessary, the tools, where possible, are to be air operated or run by explosion -proof motors and bonded to the tanks. It is noted that some tools are not available with air operated or explosion -proof motors and when used, testing for flammable vapors in the work area becomes even more critical. Therefore, when using electric tools with open switches, the work area is to be tested continuously during the operation. ' Where no hatch exists, a manhole may be cut out approximately 22" x 22". This is -9ccomplished by outlining the area to be cut out with chalk, and drilling out two holes in the tiagonal corners of the square with an air driven drill. (The cover plate can be used as a template). When the first hole is drilled into the tank the test probe will be placed into the hole to again verify that the tank is,still safe. It is important that purging is continued throughout this uist reading, should be lower than 201% Lower Explosive Limits (LEL) on the test meter. The tank should then be cut by an air driven sniper or with an explosive -proof saber saw or equivalent. A man with complete positive air displacement equipment with face mask and the proper protective clothing can then enter the tank. Tests with the explosive meter should be performed by the man in the tank to ascertain that the tank vapors are in the proper Lower Explosive Limits (LEL) range. I 7-2 Removal of Sludge The volatile lead compounds in the sludge and in the scale are a source of danger Se r •vapors which too MUTWOVAI a mospneres may contain cangerwous q foregoing hazards. No one with a punctured ear drum should enter such a tank because vapor laden air will pass through this abnormal opening. Tanks of bulk storage capacity over 50,000 gallons must have a safety inspector from Du Pont or Ethyl Corporation approve entry into a tank. Before entering all leaded gasoline tanks follow the procedure as prescribed in American Petroleum Institute Bulletin #RP2015: "'Cleaning Petroleum Storage Tanks." Employees entering the tank and those handling tank sludge will be clothed so that arms, legs, head and torso are protected from contact with the tank residue and the coating resins. They shall wear oil and water resistant boots and gloves. In addition, protective respiratory equipment providing positive air pressure in a full facepiece mask will he worn by those entering the tank before and during Bottom Sediment and Water removal, sandblasting, and removal of residue and during the coating application. Protective equipment shall be provided, used and maintained in a sanitary reliable condition. Persons working in the tank when respirators are required will be equipped with safety harnesses and safety lines and standby employees. Page 6 8180