When various types of pipes or large equipment are under aluminum raised floor, general stringer system cannot meet the installation requirements. In this case, a steel beam system can be used and is able to achieve long-span installation. According to the installation methods, there are two types of beam systems. A general beam system can meet a certain span in one direction, while a heavy duty beam system can reach the span as high as 1200mx1200mm, 1800x1800mm and 2400x2400mm.