LESSON 3 ANSWERS TO SELF TEST EXERCISES
1. Note 6 of the general notes refers you to drawing number 84-13 for details of the filter bed. (para 3-2) (fig 3-1)
2. The water tank, labeled "WTK 1," is located at the top center of the layout. The supply line is designated by a
note reading "assumed 1,000' to supply," and the pipe size of 4 inches is noted next to this line. (para 3-3) (fig
3-2)
3. The utility building -8, labeled "UTL 8," is located in the lower right-hand corner of the lay-out. By measuring
the 2-inch line leading from the 4-inch main and then using the graphic scale, a distance of 215 feet is arrived
at. (para 3-3) (fig 3-2)
4. Acid- and/or water-carrying pipes are represented by solid or dashed lines. (para 3-6,a)
5. Figure 3-6 shows pipe fitting symbols. (a) is an eccentric reducer, (b) is a concentric reducer fitting, (c) is a
screwed union, and (d) is a flanged union. (para 3-6,b) (fig 3-6)
6. Figure 3-7 lists valve symbols. (a) is the pan symbol for a straight or angled gate valve, (b) is the symbol for
an angled check valve, (c) is the elevation symbol for an angled gate valve, and (d) is the elevation symbol for
an angled globe valve. (para 3-6,c) (fig 3-7)
7. The note to the left of the sand filter specified the spacing as 5 to 10 feet. (para 3-14,b) (fig 3-18)
8. Inlet of septic tank is 1 + 64.6
164.6
feet
Manhole No. 2 is 1 + 14.6
114.6
feet
Horizontal distance
50
feet
(para 3-14,c) (fig 3-18)
9. Reference elevation for manhole No. 2
= - 192.05 feet
Reference elevation for septic tank inlet
- 192.60 feet
Vertical distance
0.45 feet
(para 3-14,c) (fig 3-23)
10. 200 feet is a convenient reference point. It is not necessarily the actual elevation of floors nor does it represent
the depth of the sewerage system. (para 3-14,c) (fig 3-23)
11. Figure 3-25 shows various symbols for electrical distribution equipment. (a) is the symbol for an air circuit
breaker, (b) is the symbol for an oil circuit breaker, (c) represents a fuse, and (d) is a capacitor. (para 3-17) (fig
3-25)
12. The connections for the primary and secondary wires are represented by black squares. Figure A-10 of the
appendix shows this symbol to be that for a cable connector. (para 3-18) (fig A-10, app A)
13. The transformers are noted as 60 cycle. A 50-amp cutout is required. The guy wire is 3/8 inch. The lightning
arrester is pellet type. (para 3-19,b) (fig 3-30)
14. An "interior wiring system" is the installation in a building which distributes electrical energy. The "electrical
distribution system" includes outside power lines and equipment for multibuilding installations. (para 3-20)
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