SR0072571 - Laserfiche WebLink

Home Browse Search

C. Surface Preparation and Coating All vessel surfaces to be painted will be properly prepared in a workmanlike manner so as to obtain a smooth, clean and dry surface. All rust, dust, and mill scale, as well as other extraneous matter, will be removed from the interior surfaces by means of near white sandblast SSPC-SP10. All external surfaces will be commercial sandblasted to SSPC-SP6. All interior and exterior vessel surfaces will be painted with 8-10 mils total dry film thickness (TDFT) of a black coal tar epoxy type coating. D. Inlet Bar Screen A bar screen will be provided at the influent port to remove any unusually large solids from the incoming raw sewage. The bar screen will be fabricated from 1/2" diameter bars spaced 1" apart and arranged as shown on the drawings. The bars shall be sloped to permit easy cleaning of accumulating debris. A deck will be furnished for drying this debris. The bar screen shall have the same protective coating as specified for the plant. E. Flow Equalization Chamber A flow equalization chamber will be supplied with a volume designed to handle 25% to 100% of the daily design flow. The flow equalization chamber allows for a constant flow through the plant by equalizing flow surges that may be incurred during peak flow times. Flow control will be accomplished by pumping the plant influent to a flow control box containing an adjustable overflow broad weir and a v -notch discharge weir. The overflow broad weir will be adjustable so that a measured amount of pumped influent will discharge through the V -notch weir to the aeration chamber, while recycling the remaining pumped influent back to the equalization chamber. A duplex set of equalization pumps will be furnished and installed within the chamber. The pumps will be rated 1/2 HP, 230 volt, 3 phase, and 60 cycle. An emergency overflow will be provided between the equalization and aeration chamber. A blower/motor unit mounted in a fiberglass housing will be supplied to meet the air requirements of the equalization chamber. The blower unit will be capable of delivering 20 CFM when operating at 5 PSI. The motor will be 1.50 HP, ODP type for operating on 230 volts, 1 phase, 60 cycle service. Liquid level sensors will regulate the pumps and blower/motor unit. Controls will be provided in the plant control panel. F. Sludge Holding Chamber The chamber will be of the aerated type. The volume of the sludge holding chamber is based on 3 cu. ft. per capita. Diffused air will be supplied by the plant blower system supplying 30 CFM of air per 1000 cubic feet of volume. The diffusers will be located parallel to and near the bottom of the tank. All piping and valves in the chamber will be factory installed. A fixed supernatant decant pipe will be provided within this chamber. 19