In making detail drawings of water-supply pipes, double-line pipes are shown, and the valves, of course must correspond, the simple line-drawing symbols not being suitable for this purpose. Further, in making up a detail drawing, some valves might be shown in an upright position, while others will be shown turned on their sides; and different symbols must be provided for each case.
Fig:. 6 Top View of Valve
Fig. 7 Side View of Globe Valve
Fig. 8 Side of Angle Valve
The top view of a valve, or the way it would look if turned on its side, is shown in Fig. 6.
This symbol merely indicates, conventionally, a valve of some description without giving any clue to its kind or make, it might be either a gate valve, or a globe valve, but would not answer for an angle valve, which would be rounded off on one end. All that is usually considered necessary in making detail drawings is to locate the various valves and show their uses, leaving to the specifications to state whether they shall be globe or gate valves, and the kind and quality. When possible however it is advisable to use the correct symbol to show the kind of valve to be used. To this end it is necessary to have symbols for detail drawings, showing all types of cocks and valves. The side view of a globe valve is conventionally shown in Fig. 7. This shows the way the valve would look standing upright when screwed onto a pipe. An angle valve, which combines the double function of a valve and an elbow, is shown in Fig. 8. This valve may be shown in its present upright position; turned on its back so that one outlet will point up; or turned so that the side outlet will point down. A check-valve would look like the side view of a globe valve with the stuffing-box, wheel, and valve-stem left off. The side view of a gate valve would be drawn as indicated in Fig. 9. If placed on its side, the symbol for a gate valve would be the same as for that of a globe valve. In addition to valves, stop cocks are sometimes used in the water supply systems to buildings, and conventional symbols are necessary to show both the T-handle and lever handle cocks. Tee handle stop cocks are shown in plan as indicated in Fig. 10, while a side view is shown in Fig. 11.
Fig. 9 Gate Valve Side View
Fig. 10 Plan of T-Handle Stop Cock
Fig. 11 Side View T-Handle Stop Cock
The symbols for lever-handle cocks, differ but little from those of T-handle, the chief difference being in the shape of the handles. The top view of a lever-handle stop cock is shown in Fig. 12, and the side view is shown in Fig. 13.
Fig-. 12 Plan View of Lever-Handle Stop Cock
Fig. 13 Side View of Lever-Handle Stop Cock
Fig. 14 Symbol for Faucet
As a matter of fact the symbols used to represent either a T-handle or a lever handle stop cock, might be used to indicate stop-and-waste cocks of the same pattern. The only way to learn definitely what grade, quality and make of cocks or valves are to be used, is to consult the specifications. The symbols show only that cocks and valves are to be used, and then approximate locations. It is left for the specifications to supply all remaining information.
Fig. 15 End View of Faucet
Fig. 16 Top View of Faucet
Fig. 17 Plan View of Drain Trap
The conventional way of indicating the side view of a faucet is shown in Fig. 14. This shows a compression type of faucet, but may be used to represent any kind or make. The end elevation of a faucet is shown in Fig. 15, and a top, or plan view in Fig. 16.
About the only fittings for the drainage system, which require symbols, are the drain traps, and the yard or floor drains. Ordinary fittings for cast-iron pipe, such as Tees, Y's and Ty's, are so familiar to all draughtsmen, that they can be reproduced from memory.
Drain traps, with two cleanout plugs, are indicated in plan as shown in Fig. 17. When the trap has but one cleanout opening, the double circle with the square inside, to the left, which is on the outlet end of the trap, is omitted. The symbol thus changed indicates the plan view of a rain-leader, or other drain trap, having but one clean-out opening. Fig. 18 shows in elevation a trap with two cleanout openings.
As in the case just explained, if a trap with a single cleanout opening is to be shown, the hub and cleanout plug to the left are omitted.
Where stacks of soil, waste and vent pipes pass up through a building, they are indicated on the plans by means of heavy circles, as shown in Fig. 19, and the size and kind of pipe are marked on the drawing. Water-supply pipes are indicated by solid disks, as shown in Fig. 20, and the size and kind of pipe are marked alongside as in the case of soil, waste and vent pipes. The location of yard, area, cellar or other floor drains is shown, as indicated in Fig. 21. If made of masonry, the catch-basin for such drains should be detailed. If stock fittings are to be used the particular kind should be specified.
Fig. 18 Side Symbol for Drain Trap
Fig. 19 Symbols for Soil and Vent Stacks on Plans
Fig. 20 Plan Symbols for Water Supply Risers
A trap is used in connection with each fixture or set of fixtures, and its presence should always be shown on the drawings. Generally, the syphon trap is used in connection with the two-pipe system of plumbing, and the non-syphon trap with the one-pipe systems. There is nothing, however, to prevent the non-syphon trap being used in connection with two-pipe drainage systems, and, so the kind of trap to be used can be told at a glance, symbols are required for both syphons and non-syphon traps.
Fig. 21 Symbol for Floor Drain
Fig. 22 Symbol for Siphon Trap
Fig. 23 Symbol for Non-Siphon Trap
Syphon traps are made as shown in Fig. 22, or the outlet leg may be turned down to form either a |-S-trap, or a full S-Trap. Non-syphon traps are indicated as shown in Fig. 23, by means of an enlarged drum, into which the inlet and outlet pipes are connected. Instead of a full S-trap, as shown in the symbol, a half S-trap can be indicated by extending the outlet pipe back to the wall. The syphon trap is used in connection with the two-pipe system of installation, and must be back vented from some point near the outlet. Non-syphon traps are generally used with the one-pipe system of plumbing and do not require to be back vented.