Energy Plant Sketching - Sectioning Methods PDF

Energy Plant Sketching • Chapter 1 Objective 3 Recognize cross-hatching methods in sectional drawings. Sectioning In order to show all the necessary details on a sketch, the object is often shown in section, or as it would appear if cut in half, through the centre line. When this is done, all the...

Energy Plant Sketching • Chapter 1 Objective 3 Recognize cross-hatching methods in sectional drawings. Sectioning In order to show all the necessary details on a sketch, the object is often shown in section, or as it would appear if cut in half, through the centre line. When this is done, all the parts that are cut through are cross-hatched or section lined. Different materials of construction can be indicated by the design of cross-hatching that is used. Figure 10 illustrates how to section line parts that are adjacent to each other. Section lines should generally be drawn at a 45° angle. Two adjacent parts should be sectioned in opposite directions. A third part, adjacent to both, is sectioned at a 30° or 60° angle. Figure 10 – Section Lining 4th Class Edition 3 • Part A 1-11 Unit A-10 • Fundamental Industrial Communication Skills Figure 11 shows the American Standard sectioning symbols used to indicate various materials. Figure 11 – American Standard Symbols 1-12 4th Class Edition 3 • Part A Energy Plant Sketching • Chapter 1 Figure 12 shows a sectioned sketch of a gate valve. Note that the internal details of the valve are illustrated by correct sectioning. The cross-hatching used indicates that the material is cast iron. Figure 12 – Section Lining in a Valve Wheel Nut Wheel Stem Packing Nut Gland Packing Stuffing Box Bonnet Gate Body Figure 13 shows the conventional method of indicating breaks in a long rod, tube, or shaft. This break is usually done when it is inconvenient to draw a whole length, or to indicate the shape to be used. Figure 13 – Indicating Breaks Round Rod Rectangular Rectangular Wood Round Tubular Round Rod and Ditto Lines 4th Class Edition 3 • Part A 1-13