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the sectioned and unsectioned parts is made by an irregular section, as shown.
Another point which will be of value to the plumber in making drawings of different fixtures, fittings, etc., is the mak. ing of threads. This we show in Fig. 69. No. 1 represents a right-hand V thread. The tool that is used in cutting this kind of thread is sharpened or ground on its cutting point at an angle of 60 deg. Consequently, in drawing the threads they are made at this same angle. If it is desired to do this work with exactness, the number threads to the inch is first found, eight being the number used in our illustration.
The upper line is then laid off into one-eighth inch spaces and the lower line also, the latter, however, being spaced one-half space or one-sixteenth in this case, in advance of the upper spaces. This is to give a pitch to the thread, for otherwise the thread would be straight up and down.
Having laid out the spaces, put in the Vs, using for this purpose the 30 deg. triangle.
All the lines sloping in one direction and first put in, and then the triangle is reversed and the lines pointing the opposite way drawn in.
The outside and inside points are then connected by straight lines. No. 2 shows a left-hand thread. The layout for both is the same, the distinction between right and left hand threads being gained by properly connecting the long cross lines.
Nos. 3 and 4 show the two kinds of thread drawn in a vertical position, and No. 5 shows a method often used for indicating a thread, where it is not desired to use so much time as is necessary in laying out a regular thread.
No. 6 shows a sectional view of a threaded piece, and No. 7 a sectional view of a hollow piece threaded on the outside. Naturally, in a sectional view, the lines connecting the top and bottom of the threads are not seen, the V only being shown.
Owing to lack of space, we omit the regular exercise for this article, and would advise in its place, practice on sections and threads.
be understood, even from careful study. In fact, the refrigerator would hide the other fixtures from view, and if shown at all, the sink and wash trays with their connections would have to be shown by dotted lines. Then again, the main lines of waste and back air serving the kitchen fixtures would also come in line with each other, and this as we already know, does not make the drawing any clearer. Consequently, conditions being as they are, it is advisable to make separate elevations of the different parts of the work.
An elevation of the kitchen work can be shown to best advantage by taking a
bottom. The only additional point that the view of the remainder of the waste would show is the connection of the vertical and horizontal lines through Y branch and bend, with cleanout. The line of pantry sinks is shown in elevation in Fig. 73, and this view is taken from a direction exactly opposite to the direction of the arrow B. A side view might have been taken of this part of the work, our reason for choosing the one shown, being to bring out a point concerning the main lines of vent and waste. In Fig. 73 they are one behind the other, the vent being in front. Being of the same diameter,
EIG.71. front elevation of it, that is, by viewing one hides the other, so that wherever the work from the direction in which the the vent line runs, only a part of the arrow B points.
hubs on the waste can show. If it had The refrigerator line can also be includ- not been for bringing out this point we ed in this elevation, which we show in should have chosen a side view of this Fig. 72.
work. Just as in Fig. 72, we have omitIt will be seen that we have not shown ted the second floor work. the fixtures and connections of the kit- Sometimes it is advisable to show in chen work on the second floor. Nothing connection with an elevation, the hori. is to be gained by showing this part of zontal line in the cellar. On these two the elevation, as it is identical with the elevations we have omitted it, however, work on the third floor, and it is omitted and for two reasons. for the sake of economizing space. For In the first place, this additional work this same reason we have not shown the would make our illustrations take up full line of waste to the point where it more space than we wish to devote to enters the horizontal line on the cellar them, and then again, by reference to the
CHAPTER XV N the preceding chapter we showed To clearly demonstrate this point, we
elevations of the work of a three- show in Fig. 75 a floor plan of the same flat apartment building, including work that we showed in connection with
the kitchen fixtures, pantry sinks the work of the preceding article, the layand refrigerators. Owing to lack of out of the floor plan being identical, and space we omitted the elevation of the the only difference being a change in the bath room work, and this we now show in locatlon of the sink and laundry tubs Fig. 74.
to another side of the kitchen. Now then, In showing an elevation of the three- in Fig. 76 we give an elevation of the flat apartment work, we brought out the entire plumbing work of the apartment
FIG. 75. point that it often occurs that a complete shown in Fig. 75. It will be observed elevation of the plumbing work of any ex- that in order to obtain this elevation the tent cannot be shown to the best advan- work must be viewed looking in the directage by taking a view of all parts of the tion in which the arrow B points. In work from one direction, and that it is this particular layout of the work the enoften best, and indeed almost necessary tire elevation is clearly shown from one to a clear understanding of the drawing, view, and it does not become necessary to make separate views of different sec- to make separate elevations of the differtions of the work, viewing each section ent lines of fixtures viewed from differfrom the most advantageous position. ent directions. It is somewhat unusual