Care must be taken when installing vimometer systems to proportion the pipes so each valve will have an adequate supply of water. No pipe in the system should be smaller than 1 1/2 inches in diameter, and four closets is the greatest number a 1 1/2-inch pipe will supply. When there are more than four closets in an installation, a safe rule is to allow in the supply main the capacity of 1-inch pipe for each closet. If, however, there is a greater number of closets than 100, it can be assumed that all will not be operating at the same time and an allowance of the capacity of 1-inch pipe be made for the greatest probable number that will be operated simultaneously.

Example

What size of water main will be required to supply twenty-one vimometer valves?

Solution

Required a pipe having the capacity of twenty-one 1-inch pipes, and Table XXXVI shows that a 3-inch pipe has a capacity of 20.9 one-inch pipes, therefore a 3-inch pipe should be used.

Low-down Combinations in which the closet tank is located at only a slight elevation above the level of the bowl are now quite extensively installed, particularly under stairways or where windows or other building details take the wall space required for an ordinary closet tank and flush pipe. The flush connection of a low-down combination is of much larger area than of an ordinary high tank closet, as the low-down combination has to supply in volume what it lacks in velocity. Low-down combinations are quite noiseless in operation and generally are satisfactory.

School Sinks and Latrine Troughs are sometimes installed in schools, barracks, hospitals and like institutions

They are very unsanitary in construction and violate almost every known sanitary requirement for a plumbing fixture. Oftentimes they are made of plain iron that corrodes and becomes foul smelling; frequently they are encased in woodwork that shuts out light and air, and that becomes filthy from deposits of soil and foul from saturation of urine; they furnish breeding places for bacteria and vermin, and worst of all, sometimes retain for hours rank and putrid substances that should be immediately removed from sense of sight and smell. Porcelain-lined iron water closets are made that are particularly adapted for hospital barracks, schools and public toilet rooms, where great strength and durability are required in a fixture, and one that can easily be cleansed with hose and broom without damage to any part. The closets are enameled both inside and out, can be had in washout, washdown or siphon-jet types, and combining as they do great strength with a durable porcelain surface, are practically indestructible.