WEEK SIX
Topic: Conventional representation of materials/ Abbreviations.
Content:
(i) Engineering material symbols
Materials symbol
Electrical materials symbol
Plumbing / piping symbols.
Plumbing symbols: The tables below show examples of plumbing symbols used in engineering drawing.
Evaluation questions
1. Draw the conventional symbol of the following items: Kitchen sink, Water closet, Shower,Wash hand basin.
2. Draw the conventional symbol of the following items: Bath tub, Gate valve, Wood, Union valve and a reduced
Elbow, Glass, Rubber.
Reading assignments
Drafting technology by W. Spence pages 541-542, 680.
Weekend Assignment
Objective
1. Which of the plumbing symbols shown below depicts a water closet?
2. What is the name given to the electrical symbols shown below? A. Colour meter. B. Distribution box. Fuse box.
B. Resistance box.
3. The electrical symbol shown below is called A. capacitor. B. transistor. C. diode. D. triode.
3. Which of the following conventional symbols of electrical components represents a variable resistor?
4. The electrical circuit below shows A. resistor, bell and switch. B. switch, capacitor and bell. C. bell, transformer
and earth. D. earth, battery and switch.
5. What is the name of the symbol shown below?
Theory
1. Sketch the diagram of the following electrical components: Lightening arrester, Transformer, Fuse box
2. Draw the conventional symbol of the following items: Kitchen sink, Water closet, Shower and Wash hand basin.
OTHERS
A Twist drill
ABBREVIATIONS
Across flats ……………………………………………………………………………………………….A/F.
Center to center ……………………………………………………………………………………………C/C.
Center line …………………………………………………………………………………………………..CL.
Countersunk …………………………………………………………………………………………………CSK.
Counterbore ………………………………………………………………………………………………… C’BORE.
Pitch circle diameter ……………………………………………………………………………………..PCD.
Undercut ……………………………………………………………………………………………………… U’CUT.
Spotface ……………………………………………………………………………………………………… S’FACE.
Standard ……………………………………………………………………………………………………….STD.
Square (preceeding a dimension ) ………………………………………………………………………
Diameter ( preceeding a dimension) …………………………………………………………………. ø
Square (in a note) …………………………………………………………………………………………….SQ.
Taper, on diameter or width ……………………………………………………………………
Specification ………………………………………………………………………………………………….SPEC.
Material………………………………………………………………………………………………………… MATL.
Drawing ………………………………………………………………………………………………………DRG.