« НазадПродовжити »
line of soil pipe underground, A full black section looks well on such work, better in fact than the section lines, which are really used mostly on larger surfaces. To distinguish the lead joints from the pipe, they are made with small dots.
The concrete floor may be made as we have indicated, and the ground surrounding the pipe in an indefinite manner, by having short lines made with the drawing pen, and interspersed with lines made with a common pen.
In Fig. 68 we have represented part of the base of a water closet, connected by brass flange of a certain style, with the lead bend; the fixture being vented from the bend. This we give to show the section of several different materials brought together on the same drawing.
It is a common thing with draughtsmen, to use certain different styles of section for different metais, especially in the drawings of machines, but for our use this is unnecessary, the main point being the use of such styles of sectioning as will clearly distinguish the different parts of the same drawing, one from the other. Thus in Fig. 68 the crockery is shown in section by dot and dash lines, the rubber gaskit by a fine dotted surface, the brass flange by 45 deg. section lines, the solder sections by 45 deg. lines drawn in the opposite directions, the lead by solid black surface, and the wood by lines representing the grain of wood. It will be noticed that the back air pipe is in sections only a short distance up, after
FIG.67 tioning them in the manner that the rest of the bibb is seen.
No. 1 of Fig. 67 represents a sectional view of a certain type of water closet. In this case the whole section is of one piece only, and in such a case, a solid black section looks well. This could not be sectioned in this manner if there were several parts to be sectioned for in using a solid color, there would be no way of making a distinction between the several parts. In plumbing drawings it is often required to represent water, and we know of no better way than that shown in connection with the water closet, that is by horizontal light lines, made up of alternate dots and dashes. It will be observed that in a sectional view of the water closet, the flushing rim would be cut through at either end, but the main part of the rim, curving backward as it does, away from the line of sectioning, would be drawn in full, in the manner in which we show it. No. 2 represents a
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 making 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 of 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.
FIG. 70. in this line, as it answers for all. In ad- each of the two ixtures, and the same dition Fig. 71 shows the cellar plan for thing would be true of the kitchen fixthe same work, the drainage pipes only tures. At this latter point the kitchen being shown, however, as in this work sink, wash trays and refrigerator would we have no use for other details.
each stand in line with the other, if A careful study of the floor plan will viewed in the direction of the arrows, A show that the arrangement of the plumb- and C, and the drawing resulting from ing is such that no one view of the whole such a view would be so confused, owing plumbing system will show all parts of to the many lines, that it could hardly 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
ELG.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