Elements of Plumbing

by Samuel Edward Dibble

Fig. 78.

Fig. 79.

Pipe and Fittings.—The pipe used in gas fitting is wrought iron or steel. In special places, rubber hose is used. Brass pipe is occasionally used to advantage. The fittings used in iron pipe gas work should be galvanized. No plain fittings should be allowed. The plain fittings very often have sand holes in them and a leak will result. Sometimes this leak does not appear until after the piping has been in use some time and the expense of replacing the fitting can only be guessed at. By using galvanized fittings, this trouble will be eliminated. All fittings used should be of the beaded type. The fitting and measurement of this work is practically the same as described under iron pipe work. To have the beginner get a clearer idea of gas-piping a building, the piping of the small building sketched will be gone over in detail and studied. One of the first important steps that a gas fitter is confronted with is the locating of the various lights and openings. With these located as shown on the plan, Figs. [78], [79] and [80], we will proceed to work out the piping. The first floor rise will be 1-inch, the second floor will be 1-inch. The horizontal pipe supplying the first floor outlets will be 3⁄4-inch pipe. The horizontal pipe on the second floor will be 3⁄4-inch. The balance of the pipe will be 3⁄8- or 1⁄2-inch. At this point your attention is called to the sketch of piping, sizes, and measurements. This sketch should be studied and understood in detail. The good mechanic will employ a sketch of this kind when installing any piping. The poor mechanic will take two or three measurements and get them out, put them in, and then get some more. This method is extremely costly and unworkmanlike. There is no reason, except the ability of the workman, why he cannot take a building like the sketch and get all the piping measurements for the job, then get them out, go to the job and put them in. The amount of time saved in this way is so great that a workman should not consider himself a full-fledged mechanic until he can get the measurements this way, and get them accurately. With a tape line, gimlet, and plumb-bob, a mechanic is fully equipped with tools to get his measurements. If the measurements are taken with a tape line, the same tape line should be used when measuring the pipe and cutting it. When laying out the piping, never allow a joist to be cut except within 6 inches of its bearing. It is good policy never to cut timber unless absolutely necessary and then only after consulting with the carpenter. When joists have to be notched they should be cut only on the top side. The pipe as it is put in place should be braced rigidly. Wherever there is an outlet pipe extending through the wall, the pipe should be braced from all sides so that when the fixture is screwed in it will be perfectly rigid.

The measurements on the piping sketch, [Fig. 81], are taken from the accompanying sketch of a dwelling, and if they were to be actually put in, they would fit. The reader would do well to copy this sketch and follow the piping and check the measurements according to the plan, and note how the different risers, drops, etc., are drawn. It is not necessary in a sketch of this kind to draw to a scale. After the different measurements are the letters C.C., E.C., E.E., C.B. and E.B., meaning center to center, end to center, end to end, center to back, and end to back, respectively. Offsetting pipe is a very convenient way of getting the pipe or fittings back to the wall for support. To offset pipe properly and with little trouble, take a piece of scantling 2 by 4 and brace it between the floor and ceiling. Bore a few different-sized holes through it and you will have a very handy device for offsetting pipe. There is a little trick in offsetting pipe that one will have to practice to obtain. The pipe must be held firmly in the place where the pipe is to be bent. Large offsets and bends should not be made; 2 to 4 inches is as large as should be used. Larger offsets that are required should be made with fittings. Always make the offsets true and have the ends perfectly straight. Before putting a piece of pipe permanently in place, always look or blow through it, to ascertain if its bore is obstructed or not. Sometimes dirt or slag will collect and cause stoppage.

Reading the Pipe Sketch.—Vertical lines represent vertical pipes (see [Fig. 81]). Horizontal lines represent horizontal pipes running parallel to the front. Diagonal lines represent horizontal pipes running from back to front. Any line that is drawn perpendicular to any other line stands for a horizontal pipe. A diagonal line separating a vertical line or horizontal line or set of lines represents a different horizontal plane. With this explanation the sketch will be made clear to one after drawing it. The reader should now take each measurement and check it on the plan. This is easily done by using a scale rule. The height of the ceiling is 81⁄2 feet on the first floor, the second floor is 8 feet. The first floor joists are 10 inches, the second floor joists are 9 inches. An outlet is indicated by a small circle. In the piping sketch, this circle is connected with the riser or drop by a horizontal line. At the junction of these two lines a short perpendicular line is drawn, and indicates the direction of the outlet.

Let me again emphasize the need to understand thoroughly this piping sketch, and to become so familiar with it that it can readily be put to use. The value of a mechanic is determined by the quality and the quantity of work that he can turn out; and a mechanic who can lay out his work and see it completed before he starts, and then proceeds to install his work, is by far of more value to his employer than the man who can see only far enough ahead to cut out two or three measurements and spends most of his time walking between the vise and place of installing the pipe.

Testing.—The system of gas piping must be tested before the pipes have been covered by the advance of building operations. If the job is of considerable size, the job can be tested in sections, and if found tight the sections can be covered. The necessity of having the piping rigidily secured can be appropriately explained here. If the test has been made and the system found tight and some pipe that is not securely anchored is accidentally or otherwise pushed out of place and bent by some of the mechanics working about the building, a leak may be caused and yet not discovered until the final test is made after the plastering is finished. The expense and trouble thus caused is considerable and could have been avoided by simply putting in the proper supports for the pipe.