Ladder preferred position

The preferred positions for ladders, stairways, and ramps are illustrated in Exhibit 12-2. It is recommended that ladders be run vertically to a maximum angle of 15. Stairways should be limited to a maximum angle of 50° off the horizontal plane, but they should not be used for less than a 15° incline. Ramps should be limited to a 15° maximum incline. A stairway dimensional detail is shown in Exhibit 12-3. The... 

A possible explanation for the formation of this planar ladder structure can be found in the close geometrical similarity of 7 to (3-gallium. The relative positions of the Ga atoms in 7 are comparable to those found in (3-gallium (see Fig. 18), but as expected, the Ga-Ga distances in 7 are all shorter than in (3-gallium due to a more molecular kind of bonding. This means that in 7 the formation of metalloid structures is preferred over the formation of polyhedral structures, which results in the unusual arrangement of the Ga atoms. 

Tower piping is located in conjunction with tray, nozzle, and platform orientation. Xdien possible, the piping is grouped for ease of suppon and positioned to accommodate interconneaion with related equipment and the pipe rack. Exhibit 10-51 shows the preferred areas of division for piping, platforming, and ladders. 

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