Jet-siphon closets are not provided with vent openings in the closet proper, except for the local bowl ventilation. Wash-out traps are, or should be, vented. The simple hopper and trap should be vented in the trap. Wash-down siphons, generally, are not vented, but it is permissible to vent them low down in the outlet leg of the trap.
All closets for indoor use should have flushing rims. In all earthenware closets and in some forms of iron closets, the rims are made integral; but the iron rims are, as a rule, separate pieces, form ing a water channel around the bowl. The bottom, inner edge of the iron rim hugs the wall of the bowl as closely as practicable, and the bulk of the water falls through regularly spaced serrations. Various provisions in the shape of barriers opposite the flush inlet, per forated race-way shelves along the rim above the exit openings, etc., are made to insure the rim filling and flushing properly all around.
All kinds of closets were formerly made without regard to the kind of seat to be used. Boxed-in cabinet seats, self-supporting, were universal. These gave way to seat and frame, with wall and leg support. To-day closets are commonly made with base flanges designed to support the weight of the person, and are provided with lugs or seat-shelf for attaching the seat directly to the bowl, as seen in Fig. 40. Metal post hinges are best in every way, if well made and strong. The competition goods, however—made to sell rather than so light as neither to keep the seat in place nor to aid in hold ing it together under the severe strain. The hinged wood-cleat seats bolted to the closet are strong, but are objectionable because they cannot be kept dry or clean under the cleat.
Closets are operated with pull or push-button tanks requiring the attention of the user; and are also made of the seat action type. Children are likely to be for getful, and visitors to public toilet rooms indifferent, to such an extent that auto matic closets are desirable for public places and schools.
Closets are fitted with two styles of tanks—one placed about 7 feet from the floor and serving with a flush pipe never more than 11 inches in diameter; and the other placed low down, as close to the bowl as connections will permit. Examples of the and low tank arrangements are shown in Figs. 41 and 42, respectively. The
low tanks are wider and deeper than the high style, but d: not ext.nd out from the wall so much. The low position delivers the water at much less velocity than the elevated style, and, to secure the utmost speed and the volume necessary, the flush connection is never less than 2-inch in a low-tank closet. The rim and jet channel are proportion ately larger in bowls intended for use with low tanks. High tanks are about 17 by 9 by 10 inches. Sheet lead and sheet copper are used for closet-tank linings. Some kinds of water, through galvanic action, attack the soldering of the seams in copper-lined tanks with more effect than where lead alone is used. Generally, however, copper lined tanks give satisfaction if the copper is heavy enough (12 to 16 oz.) and properly put in. Some makers lock-seam the linings water-tight, and solder on the outside before placing the copper in the wood case.
On account of the greater depth of low tanks, swelling of the wood case has, doubtless, been the cause of most of the trouble experienced with this type. When put together in the factory, the wood is very dry, and after being used for a short time, increases in height as a result of swelling from dampness. If the lining be tacked to the wood at bottom and top, in jury is sure to result. If tacked at the top only, the copper will soon be support ing the water without help except where the connections are It is now the practice to omit fastening the lining. Very great care has been found necessary with ball cocks for low tanks, in order to secure proper after-fill, the flush connection being too short to aid much in resealing the bowl with its drainings.
Low tanks flush with much less noise than high ones, and permit placing the closet under windows and low ceilings. Low ones require more width on account of the tank, and more depth from the wall to the front, as the seat and lid must be placed far enough forward to be thrown back and remain leaning against the front c" the tank. Low tanks are provided with ventilated covers; while the high pattern, which is out of children's reach, is left open at the top. The fewer working parts in a tank, the less likely it is to get out of order.