The interior and exterior metalwork of the cover, the exposed portion of the concrete tank on Secondary Digester #1, and the gas piping shall be re-coated. The floating digester cover is approximately sixty (60) feet in diameter with a very gentle sloping rise to the center gas collection dome. There is a metal skirt approximately ten (10) feet high that is continuous around the perimeter of the cover. The cylindrical gas collection dome which is 6.25 feet in diameter and approximately 4 feet high is located in the center of the cover. The underside of the cover has a system of support trusses numbering twelve (12) that extend radially from the center to the outside edge of the cover and down along the skirt wall of the cover. Each truss is approximately twenty-seven (27) feet long by six (6) feet high and made of angle iron with an I-Beam running top to bottom on the skirt wall. There are approximately ten (10) flapper valves to be re-coated, each approximately eight (8) inches in diameter, evenly distributed around the inside of the concrete tank wall. Two (2) eight-inch sampling wells that extend approximately ten (10) feet down through the cover into the tank shall be re-coated. The four (4) manholes and lids which penetrate the cover are to be re-coated. There are six (6) cover guide wheel slots evenly spaced around the skirt of the tank wall running from the top of the cover and descend helically to the bottom of the skirt. There are other small appurtenances which are integral parts of the cover and are included in this scope of work to be re-coated. Cover may not be removed from tank for re-coating.
