Understanding API ICP653 Reading 7-Worksheet-04 Part1

9.10.2 Replacement - Entire Bottom
9.10.2.1.1 Non-corrosive material cushion (i.e., sand, gravel or concrete) 3"-
4" thick shall be used between the old and new bottoms.
9.10.2.1.2 The shell shall be "slotted" with a uniform cut made parallel to the
tank bottom.
9.10.2.1.3 Voids in the foundation (below the old bottom) shall be filled with
sand, crushed limestone, grout or concrete.
9.10.2.1.4 Raise elevation of existing penetrations if the new bottom elevation
requires a cut through the reinforcement.
9.10.2.1.5 On floating roof tanks, keep in mind that the floating roof support
legs may require revision to conform to new bottom elevation.
Charlie Chong/ Fion Zhang