SECTIONAL VIEWS Sectional view of a centrifugal pump

SECTIONAL VIEWS Sectional view of a centrifugal pump Radial section Sectional view of a leaf Axial section TO VIEW FEATURES THAT ARE HIDDEN IN AN UN-SECTIONED VIEW

Section Plane Triangle Through Apex Section Plane Through Generators Ellipse Par abo la Typical Section Planes & Typical Shapes Of Sections. Section Plane Parallel to end generator. Ellipse Cylinder through generators. Section Plane Hyperbola Parallel to Axis. Trapezium Sq. Pyramid through all slant edges

Direction of viewing for TV ILLUSTRATION SHOWING IMPORTANT TERMS IN SECTIONING. SECTION PLANE TRACE LINE (egde view) a’, b’ F. V. c’, d’ x Apparent Shape of section The section is drawn by projecting the points where the section plane intersects the edges of the solid and joining them y c b a d SECTIONAL T. V. SECTION LINES (450 to axis or outline, preferably not parallel to an outline)

Notations for cutting planes Ref: Fundamentals of Engg. Drawing, Luzadder End point of object Section plane denoted by different methods Arrows point towards the remaining part

Section more than one component in the same drawing (e. g. concentric cylinders) Section lines of adjacent components are drawn in different directions Section lines for alternate components can be drawn in the same direction but with different spacing between section lines

Sectioning a solid • It is required to see features that are not clear in an unsectioned view Usually hidden lines behind the section are not drawn REF: http: //www. tpub. com/content/draftsman/14276/css/14276_190. htm

Section lines at 45 o to adjacent axis, lighter than the outlines Section plane FRONT VIEW SIDE VIEW SECTIONAL SIDE VIEW

Ribs (used for strengthening, positioning) Rib A A Rib not sectioned even though cutting plane passes through it 8

Ribs (used for strengthening, positioning) Rib B B TV B B Viewing direction Sectioned SV Full FV 9

Types of sectional views (Used for showing outer and inner features on the same figure) “It is considered good practice to omit all hidden lines unless such lines are necessary to clarify the representation. ” “Good practice dictates that hidden lines be omitted from both halves of the view unless they are absolutely necessary to explain the object. ” EXAMPLE TAKEN FROM BOOK BY LUZADDER AND DUFF 10

Full section Offset full section 11

Section B-B Section A-A 13

Each section has been drawn separately C Section C-C C Section B-B Rib not sectioned Section A-A 15

Draw orthographic views showing sections P-P and R-R

Draw orthographic views showing the section indicated