General Specifications for NRG COMPANY, INCORPORATED Chain and Flight Skimmer Equipment Part 2 - Products 2.1 Fiberglass Flight Skimmer Blades A. Flights shall be fiberglass reinforced plastic (frp) material and shall be 3"x 6" or 3"x 8" nominal dimension. The flight shall be a pultruded channel type specifically designed for sludge collector service. The flight shall include a scraper lip on its leading edge designed to clean the surface of the tank floor. The face of the flight shall have a minimum thickness of 1/8" and the legs of the flight shall have a minimum thickness of 3/16". The flight shall be manufactured with a minimum of 55% (by weight) continuous fiberglass running the full length of the flight and shall be in compliance with ASTM-D638-94. Flights must contain a minimum of 45% resin compound to provide adequate corrosion resistance and protection of glass fibers. Angle type flights, buoyant flights, lipless C-channel flights, or L shaped flights will not be acceptable. Flight designs which retain or recirculate solids will not be acceptable.   B. Each flight shall be equipped with a neoprene wiper blade, slotted for adjustment and fastened to the front of each flight with an FRP backer plate and stainless steel bolts spaced at one foot intervals.   C. The flights shall be accurately drilled and notched by the equipment manufacturer at the factory to ensure the proper fitting of the flight attachments and wear shoes.