(A) (1) All welding shall be in accordance with AWWA D100 § 8, Welding and § 11, Inspection and Testing. This requires all welders to be certified in accordance with AWS Dl.1.
(2) All welds to the tank surface shall be made with E7018 low hydrogen rod and shall be smooth and free of burs and undercuts. Unacceptable welds shall be repaired as 6.1 requires to meet AWWA D100 requirements.
(3) Penetrations shall not intersect tank weld seams. Penetrations should clear existing seams by 6 inches. If this clearance is not possible, a review by a professional engineer shall be made of adjacent weld seams that may be affected by local welding.
(4) Welding to the tank or access tube opposite the water level is not permitted. The water level shall be drawn down to a level not less than 2 feet below the point of welding.
(5) Galvanized components shall not be welded directly to the tank surface. Galvanized surfaces mating to the tank structure must be ground free of galvanizing prior to welding.
(6) Tubular columns on multi-leg supported tanks are hermetically sealed and must not be breached or punctured under any circumstance since moisture will accumulate inside the leg and eventually cause serious structural damage.
(B) Welding may cause blistering of the interior paint opposite the weld. Damaged interior paint surfaces shall be repaired in a manner that is compatible with the existing paint system. Exterior paint damage shall be repaired after completion of the antenna installation, and should be compatible with existing paint system. It is recommended that a 1-year anniversary inspection be made to evaluate the quality of the touch up and repainting if required. AWWA D 102 should be consulted for proper paint procedure.
(Ord. passed - -)