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CHAPTER XXV
ONCERNING the drawing of pip- the former showing wrought iron pipe,

ing, there is nothing connected and the latter lead. In each of these illus-
with it which differs at all in trations, A and B represent globe valves

principal from the work which in two positions, A being seen from the we have already been over. Consequent side, and B from a position where the ly, the illustration which we present, wheel appears in front of the valve. will cover the greater part of the sub These same positions respecting the stop ject.

cock are shown at C and D. E shows a Figs. 137 and 138 show the water pip

bibb. ing connected with range Voiler work, A simpler and quicker way of showing

this work, and one that is often just as

desirable, is shown in Fig. 139, A, B, and BO

C showing respectively a globe valve, stop cock and bibb.

If it is desired to make a distinction between the hot and cold pipes, it may be done by drawing one with solid lines, such as Fig. 139 shows, and the other by dotted lines. The same effect can be obtained very satisfactorily by showing the cold pipes with blue pencil or ink, and the hot with red. We might add, by the way, that this method is often followed in making the distinction between the drainage and the venting system of plumbing work.

Comparing Fig. 137 with Figs. 140 and 141, it will be seen in the former that the fittings are made of the same diameter as the pipe, while in the latter, which show larger sized pipes, the size of the fitting is made larger than the pipe.

The latter method is usually adopted in showing steam piping, while the former is used in water piping.

In Fig. 140, A, B, C and D show respectively the ell, reducing ell, tee, and reducing tee.

Fig. 141 shows 45-degree connections, with the main, from which the connec

tion is taken, showing sidewise, while Fig. 137.

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Fig. 147.

Fig. 145. Fig. 143. take the centers for the curves on this line, being sure of course to put in the curves before the straight lines are drawn.

The drawing of a coil of ordinary pattern, such as shown by Fig. 147, needs

will be on an angle of 45 degrees, such as the dotted line shows in the sketch.

Having put in this line, which should be done in light pencil, the centers for striking the curves of the several ells may be taken on this line.

In taking up much of the work considered in this article, we are not adhering strictly to the requirements of the plumber, but as the work of the plumber and fitter are so closely allied, this work will prove of value to the average plumber we believe.

Our readers will find plenty of good practice work in the illustrations which we have presented in this chapter, and the drawing of valves, radiators and coils will be found of special value.

Fig. 146.

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CHAPTER XXVI THE showing of steam pipes on while B is obtained by looking downward

floor plans is a matter that calls from the left. Either of these two views for attention, and in this con- is very common, much more so, we may

nection we give Figs. 148 and say, than views obtained by looking up149. The method shown in Fig. 148 is ward upon the object. C shows a conthe one which is probably most used, the nection which is viewed from the left pipes being represented by single lines, and on a level with it, instead of downand the risers by circles.

ward or upward, and occasionally is a The other method shown in Fig. 149 desirable method to follow. D shows a has the advantage of showing the connec little more difficult perspective than those tions of branches with the main, more in preceding, and E shows valves in two difdetail than the method just mentioned. ferent positions, in perspective. A glance at the sketch will show that the A close study of these examples of pertee on the main is turned at 45 degrees, spective will show that the ellipses which

are seen on the fittings are square with Jo Raat

the direction of the pipe, no matter in what direction the pipe may run.

Compare F and G, which are supposed to represent the same thing. The ellipses in F are not square with the fitting

or pipe, while those in G are. The result Boiler

is apparent. The tee in F is distorted, while that in G is not.

If our reader will hold a piece of pipe in front of him with the end pointing

toward him, that end will appear as a full Fig. 148.

circle, but if he will turn the pipe from and a 45-degree ell brings the branch

this position gradually until it stands level again.

lengthwise instead of endwise, this circle Now we come to the matter of showing will become an ellipse, gradually narrowpiping in perspective, the last point ing, until finally, when in a position which we shall take up in this series. lengthwise, no part of a circle or ellipse It is of much importance, for it will be is to be seen, simply the square end befound that it is used a great deal, and

ing seen. furthermore, many systems of heating

Perhaps this crude example will exare very difficult to illustrate by any plain why, in this perspective work, the other means.

circles on the fittings appear as ellipses. To get into this subject we show In making a rule for this work we can several simple examples of perspective in perhaps do no better than to say that the Fig. 150.

straight lines of pipe should be first put A represents a connection which in- in, in their proper directions, and the spection will show is viewed by looking fittings connecting them put in afterdown upon the object, and from the right, ward, and as previously stated, care be

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ing taken that the ellipses are square with the piping.

To make an application of the work shown in Fig. 150, we give Fig. 151, which represents a heater with its piping. it

the boiler. In perspective, all vertical lines appear vertical, hence all the risers in Fig. 151 are vertical.

The line of pipe S-T is at right angles to the boiler and therefore must be parallel with the front line of the boiler, that is, horizontal. The lines A-B and K-L are of course parallel with the lines V and W of the boiler, and must therefore be drawn in that way, that is, at 60 degrees with the horizontal.

The lines of pipe shown at C, D, M and N are parallel with S-T and E-F, and are therefore drawn horizontally with the tee square.

The lines of pipe shown by G, H, P and R being on the work itself parallel to A-B and K-L are drawn parallel, that is, at 60 degrees with the horizontal.

In Fig. 151 we have lines of pipe running in four different directions in addition to the vertical lines, and we believe that this sketch will cover the ground

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Mechanical Drawing for Plumbers. Sketch Showing a Heater and its Piping.

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