As you can see in example A, the length of the dashed line is equal to the RISE of the box, and in example B, the dashed line drawn diagonally across the end of theīox is equal to the RUN of the box. When solving a right triangle whose angle is 45°, the SA and SO will always be equal. The TRAVEL of the pipe becomes the hypotenuse for either triangle. Depending on the type, vertical or horizontal, two different 45° right triangles will be formed. When a pipe enters and exits in the horizontal direction, a 45° angle is formed between the TRAVEL and the RUN of the box. When a pipe enters and exits in the vertical direction, a 45° angle is formed between the TRAVEL and a dashed line drawn diagonally across the bottom of the box (hypotenuse of triangle 3). Example B shows the pipe to enter and exit the box in the horizontal plane. In example A, the pipe enters and exits the isometric box in the vertical plane. Figure 13-29 shows the two examples of the ways pipes enter and exit the isometric box. The values used to determine its length depend on how the pipe enters and exits the isometric box. This length is the most difficult to calculate. It establishes the true length of the pipe from the upper plane to lower plane across the box. Notice the dimension labeled TRAVEL in Figure 13-25. Rolling offsets are typically fabricated using 45° elbows therefore, the vertical angle will be 45°. The RISE is determined by subtracting the lower plane elevation from the upper plane elevation. Notice the SA of triangle 3 in Figure 13-28 is equal to the RUN of the box, the ROLL of the box is equal to the SO of triangle 3, and angle X of triangle 3 is the same as the horizontal angle (HOR°).

When a rolling offset is part of a configuration similar to that shown in Figure 13-28, the lengths of the sides of triangle 3 are applied to the dimensions of the isometric box (see Figure 13-25). There are four length dimensions and two angular dimensions. Figure 13-25 identifies the six measurements required to dimension a rolling offset.

Piping isometric rolling drawing pdf