The plumbing systems for schools, factories, etc., and for such buildings as apartments, are very much more complex than those for residences and small dwelling houses, and call for the solution of problems of a considerably different nature. In this larger work, especially in the toilet rooms of schools, hotels, and various other public buildings, long lines of fixtures must be provided for, and upon such work much judgment and skill may be displayed.

This is true, for instance, in the connections for lines of lavatories. The old method of performing this work was according to Fig. 195, in which a single trap is made to serve the entire line. This is obviously a poor method.

Fig. 195.   Poor Method of Connecting Line of Lavatories into One Trap.

Fig. 195. - Poor Method of Connecting Line of Lavatories into One Trap.

Whenever the trap stops up, as it is almost sure to do sooner or later, not one only, but the entire number of lavatories is rendered useless, until the stoppage is removed. Another objectionable feature is the fact that foul waste pipe running the entire length of the line of lavatories is constantly throwing its impure odors into the room through the several lavatory outlets. An improvement over this method is shown in Fig. 196, these connections giving each lavatory separate entrance into the main waste line, with opportunity for a cleanout in the end of it, by means of which any stoppage on the main may be removed. The chief objection to this method, however, is the great possibility of the stoppage of the vent openings into the traps. This feature, as shown elsewhere in this chapter, may be very successfully overcome by the use of continuous venting. In another chapter, also, may be seen an illustration of a line of lavatories connected up with continuous vents. Not only is their use a great improvement from a sanitary standpoint, but ofttimes it results in great economy in the expense for labor and material, especially when two lines of lavatories or sinks back up to each other. Lines of urinals may often be connected to advantage in this same way. Although sometimes used on residence work, the urinal is a fixture found principally in large buildings of a public or semipublic nature. The common type of urinal and its connections are to be seen in Fig. 197. The subject of urinals, by the way, is considered at length by the author in his "Modern Plumbing Illustrated."

Fig. 196.   Proper Connections for Line of Lavatories.

Fig. 196. - Proper Connections for Line of Lavatories.

Fig. 197.   Connections for Urinal.

Fig. 197. - Connections for Urinal.

Fig. 198.   Ordinary Method of Venting for Toilet Rooms of Schools, Factories, Etc.

Fig. 198. - Ordinary Method of Venting for Toilet Rooms of Schools, Factories, Etc.

Fig. 199.   Circuit Venting for Toilet Rooms of Schools, Factories, Etc,

Fig. 199. - Circuit Venting for Toilet Rooms of Schools, Factories, Etc,.

For public work, the massive porcelain urinals now in use are excellent, inasmuch as they are very cleanly, a feature greatly to be desired in urinals, which as ordinarily constructed and installed, are the most objectionable of all fixtures.

The pedestal urinal is one of the modern forms of urinal which is also very desirable.

In Fig. 198 is shown an elevation of the plumbing of toilet rooms for such buildings as hotels, schoolhouses, factories, etc., installed according to the approved methods in vogue in most cities at the present day. In Fig. 199 is shown an elevation of the same system installed with circuit vents, which subject is considered elsewhere in this work.

In many cases public toilet rooms may be served to better advantage by the circuit-vent system than by that shown in Fig. 198. It will often be found to decrease both the complication and the expense of the work. When there is but one toilet room, and it is desired to provide the water-closets with a circuit vent, the work may be performed according to Fig. 200, the vent in this case being known as a loop vent, from the manner in which it loops over the line of fixtures.

Very often, especially in public buildings, owing to the style of building construction, trap vents must be run to a point above the ceiling, and then horizontally into the main vent line, as seen in Fig. 201. The latter illustration shows the work put in under the Durham system, which has come into extensive use in public-building work, notwithstanding the serious objections to its employment.

Fig. 200.   The Loop Vent.

Fig. 200. - The Loop Vent.

In the matter of ventilation for public toilet rooms, the local

Fig. 201.   Bath Room Connections, Durham System; Galvanised Wrought Iron Wastes and Vents.

Fig. 201. - Bath-Room Connections, Durham System; Galvanised Wrought Iron Wastes and Vents.

Wash sinks for school and factory use and for similar purposes, are a subject of importance. For this purpose there are several good makes that may be obtained, among them those shown in Fig. 203, which represents a single line.

Fig. 202.   Ventilation of Line of Water Closets in Public Toilet Room.

Fig. 202. - Ventilation of Line of Water-Closets in Public Toilet Room.

Fig. 203.   Wash Sinks for Schools, Factories, etc.

Fig. 203. - Wash Sinks for Schools, Factories, etc.