Indicating Plumbing Work On Plans

Conventional characters or symbols must be used to indicate plumbing work and fixtures on plans, just as symbols and lines are used to indicate doors, windows, steps, partitions and other structural details on architectural drawings. At the present time there is no uniformity in this respect, and the lack of standards often leads to serious confusion. For instance, if plans from ten different offices are examined, the chances are that on no two of them will the symbols be alike. Further, plans prepared in the same office at different times, or one set of plans on which different draughtsmen have been working, will often show as many different symbols for a water closet or lavatory, as there were workmen engaged on the drawings. That is rather confusing to plumbers who must take off quantities from the plans; for, oftentimes the symbols used are so strange, and bear so little resemblance to the fixtures or apparatus, that some of them are overlooked by the estimator.

In the following pages some simple, easily made, yet at the same time characteristic symbols are suggested as standards for use in architectural offices. Their general adoption will not only be appreciated by plumbers, but will simplify and make more definite and certain the preparing of plumbing plans.

There are various kinds of pipe used in a plumbing installation, and it is necessary for the estimator and contractor to be able to distinguish between them at a glance. For this reason, the drainage system is drawn in an entirely different manner than the water-supply system; and the difference can likewise be distinguished between cast-iron and wrought pipe.

Cast-iron soil pipe is indicated on drawings by means of two lines, as shown in Fig. 1, with hubs at 5-foot intervals, and at fittings. The distance between the lines need not be drawn to scale, as that would sometimes bring the lines too close together, and it is found better in practice to draw them out of proportion, when necessary, in order that they will stand out strong in the illustration. The sizes can then be marked alongside of the pipes, beginning where the drain enters the building. Once the size has been indicated, that size is supposed to continue until a smaller size is marked.

Fig. 1 Symbol for Cast Iron Pipe

Fig. 1 Symbol for Cast-Iron Pipe

Fig. 2 Symbol for Wrought Pipe

Fig. 2 Symbol for Wrought Pipe

Wrought-iron or steel pipe is indicated by means of two parallel lines, as in the case of cast-iron pipe, but with the difference, that hubs are omitted at 5-foot intervals and fittings or joints are indicated only where a branch connection or a bend in the pipe is to be made. Wrought pipe for water-supply is never shown in double lines on the plans or general drawings, so that when double-line wrought pipe is marked, drainage work is always understood. On detail drawings, however, showing runs of water pipe, the double line method is used, that being the better one for the purpose. Wrought pipe, such as used for drainage work is shown in Fig. 2. By comparing the Y fitting with the similar fitting on cast-iron pipe, shown in Fig. 1, the difference between the symbols for a cast-iron soil fitting and a recessed drainage fitting will be readily seen.

Lead pipe is indicated by means of two parallel lines bent to fit any position or follow any direction. The junction of one lead pipe with another, at an angle, is indicated by a branch joint, as at a, a, Fig. 3; and where a lead pipe is connected to a brass ferrule or solder nipple, that fact is indicated by a wiped solder joint Sometimes branches are connected together, as at 6, without indicating a solder joint.

Water supply pipes on plans and general drawings are shown by means of single lines made solid, dotted, dashed or crossed, so as to indicate the different uses. For instance, if there were hot and cold, fresh and salt water to be supplied to a seaside hotel, the various pipes, together with circulation pipes, pump pipes, or any other kind that it might be necessary to show, could be indicated by lines similar to those shown in Fig. 4. Whatever symbols were used for this purpose, however, should be indicated on the plans with the key to explain their meaning, substantially as shown in the illustration. The lines shown in the illustration need not be used as a matter of necessity, but any arbitrary lines will do so long as there is a key furnished to explain their uses.

Fig. 3 Symbol for Lead Pipe

Fig. 3 Symbol for Lead Pipe

Fig. 4 Symbols for Water Pipes

Fig. 4 Symbols for Water Pipes

Characters will be found useful on water pipes showing where valves are to be placed, and this necessitates a set of symbols to indicate the various kinds of valves on solid or dotted line drawings. The side view of a globe valve for one-line pipe symbols, can be made as shown at (a) in Fig. 5, and the side view of a gate valve can be made as shown at (6). Having symbols to indicate the two principal kinds of valves will often be found convenient, as not only the location but likewise the kind of valve can frequently be shown. The plan view of either a gate valve, or a globe valve would be made as shown at (c). Looking down on a valve, there is nothing to distinguish one kind from another. When necessary to differentiate, however, the side view of the respective valves can be shown in plan. Angle valves are made as at (d)

Fig. 5 One line Symbols for Valves

Fig. 5 One-line Symbols for Valves

Check valves are not frequently required, but when they are may be drawn as shown at (e). As the top view of a check valve would not differ much from the side view, for the sake of simplicity, the one symbol may be used in either position.