Description
The US Army Corps of Engineers, Tulsa District, is conducting market research for the procurement of 14 new generator air coolers for the Broken Bow Powerhouse in Oklahoma. The air coolers must be designed to achieve an increase in cooling capacity of at least 20% compared to the existing coolers. The contractor will be responsible for designing, manufacturing, and delivering the air coolers, as well as providing material certifications, as-built drawings, pressure test reports, and calculations prior to delivery. The contractor must also perform leak tests and provide certification prior to acceptance by the government.
Some key requirements for the air coolers include:
* The material in contact with water must be the same for the tubes, tube sheet, water boxes, and connections.
* The air coolers must match the dimensions and layout of the existing coolers, including supply, drain, and vent connections.
* The manufacturer must provide material certifications, as-built drawings, pressure test reports, and calculations prior to delivery.
* The test pressure shall be a minimum of 200 psi.
* The contractor shall perform leak tests and provide certification prior to acceptance by the government.
* The air coolers must be of the straight tube type, with fins consisting of a double tube employing an out-aluminum tube from which the integral fins are extruded, and which is continuously mechanically bonded to the inner stainless steel water tube.
* The outer tube must be made of aluminum having a purity of not less than 99.5 percent, conforming to ASTM B241.
* The fins must be spaced no more than 11 fins per inch.
* The inner tubes must be stainless steel conforming to ASTM A213, type 304 or 316, with at least 1 inch outside diameter.
* The tubes must be expanded into the tube sheets, and laterally supported as necessary to prevent resonant frequencies from occurring within ± 15% of forcing frequencies with a generator speed of 128.6 RPM.