GB2034368A - A drainage installation - Google Patents

Abstract

In a drainage installation for a multi-storey building comprising a single vertical main drain pipe 1 opening at its upper end into the atmosphere, there is provided at each storey a substantially C-shaped by-pass pipe 2 connected at its two ends 3, 4 to the vertical main drain pipe, the vertical portion 5 of the pipe 2 having a transverse branch pipe 6 connected to the drain pipes 7 extending from the sanitary fixtures 8 of that storey. The use of C- shaped pipes 2 provides loss of water seal in the traps of the sanitary fixtures and thus avoids the need for vent pipes. <IMAGE>

Description

SPECIFICATION Drainage installations This invention relates to drainage installations associated with various sanitary fixtures in multi-story buildings such as hotels, apartments, etc.

Usually a building drainage installation comprises a vertical drain pipe opening at its upper end to atmosphere and having transverse branch pipes which extend transversely at each story of a building and are connected through drain pipes to sanitary fixtures. Water-sealed traps are provided on sanitary fixtures themselves or in their drain pipes to prevent odor or harmful insects from getting upstream into rooms.

However, when water momentarily flows to fill some portion of the vertical drain pipe, negative pressure may arise in the transverse branch pipes close to said portion, drawing sealing water from water traps through the branch pipes into the vertical drain pipe. Or, when the lower portion of the vertical drain pipe is momentarily filled with flush water from sanitary fixtures and, at the same time, additional water flows down from the upper portion of the vertical drain pipe, the air trapped in between said two portions may be compressed to build up positive pressure in the transverse branch pipes associated therewith, expelling sealing water in watersealed traps into rooms.

To eliminate these undesirable phenomena, a long vertical vent pipe is generally provided, having its top and bottom ends connected to the upper and lower portions of a vertical drain pipe, said vertical vent pipe being connected through loop tubes to transverse drain pipes to eliminate the pressure variation in the transverse drain pipes with air from said vertical vent pipe.

This arrangement is effective for preventing negative or positive pressure in the transverse drain pipes which tends to remove sealing water from water traps, and therefore, it is utilized widely on a commercial basis.

Due to the fact that the arrangement explained heretofore requires a long vertical vent pipe and many loop vent tubes, however, it is not considered preferable from the view point of construction cost.

According to the invention, there is provided a drainage installation in a multi-storey building which installation comprises a main downwardly extending drain pipe provided at each storey with a by-pass pipe connected at each of its ends to the main drain tube and connected through one or more branch pipes to sanitary fixtures on its respective storey. A preferred drainage installation for multi-storey buildings comprizes a substantially vertical drain pipe opening at its upper end into atmosphere, a substantially C-shaped pipe at each storey of a building connected at its ends to said vertical drain pipe and a transverse branch pipe connected to a vertical portion of said C-shaped pipe, said branch pipe being in connection with drain pipes extending from sanitary fixtures at its respective storey.

With this arrangement, when a mass of water momentarily filling a portion of the vertical drain pipe flows down, negative presure will be produced in the transverse branch pipes close thereto. However, air is supplied from the vertical drain pipe through either the lower or the upper portion of the C-shaped pipe into the transverse branch pipe to eliminate the negative pressure therein, thus, preventing sealing water in the traps from being sucked out.

Further referring to the aforementioned positive pressure built up in the transverse branch pipe, as soon as water from the upper portion of the vertical drain pipe flows down past the upper horizontal portion of the C-shaped pipe, the compressed air under the falling water in the vertical drain pipe is vented through the lower horizontal, vertical and, then, upper horizontal portions of the C-shaped pipe to the upper portion of the vertical drain pipe, rapidly reducing the pressure of trapped air in the vertical drain pipe. Thus undesired positive pressure built up in the transverse branch pipe is perfectly eliminated.

The drainage installation for multi-storey buildings according to the invention will now be illustrated by way of an example with reference to the accompanying drawings, in which: Figure 1 is a schematic illustration of a drainage installation of the invention; Figure 2 is a perspective view showing the detail of a portion of the drainage installation.

Referring to Fig. 1, the vertical drain pipe 1 is of conventional design known in the art, opens at its upper end to atmosphere, and has at its lower end a horizontally extending portion to be connected to a sewage system.

The substantially C-shaped pipe 2 comprises the upper portion 3, the lower portion 4 and the vertical portion 5 extending between said two horizontal portions, said C-shaped pipe 2 being connected through its upper and lower portions 3, 4 to the vertical drain pipe at each storey of a building.

As shown in detail in Fig. 2, a transverse branch pipe 6 is connected at its one end to the vertical portion 5 of the C-shaped pipe, and at the other end through a water-sealed trap and a fixture drain pipe to each of various sanitary fixtures 8 such as water-basins, bath tubs, stools etc. in a conventional manner.

Now the drain water is routed from those sanitary fixtures 8 through the fixture drain pipes 7, the transverse branch pipe 6, the Cshaped pipe 2, and the vertical drain pipe 1 down to a sewage system. Whenever drainage from sanitary fixtures is finished, sealing water is trapped in between the fixture drain pipes and the fixtures, preventing odor in the drain pipes from reaching rooms.

Because the transverse branch pipe 6 is connected through the upper and lower portions 3, 4 of the C-shaped pipe to the vertical drain pipe, air is supplied from the vertical drain pipe to the transverse branch pipe through either said upper 3 or lower portion 4, and therefore negative presure is never built up in the transverse branch pipe, even through pressure in a portion of the vertical drain pipe is made negative when drain water momentarily filling the vertical drain pipe flows down.

Further, assuming that flush water is drained from sanitary fixtures and blocks the lower portion of the vertical drain pipe, whereupon additional effluent water flows down from the upper portion of the vertical drain pipe; air is caught in between the blocking water at the lower portion of the vertical drain pipe and the falling water from the upper portion thereof, and gradually compressed.

However, each time the falling water mass meets the C-shaped pipe and runs down past the upper portion thereof, the compressed air in the vertical drain pipe is relieved through the C-shaped pipe to the upper portion of the vertical drain pipe, thus preventing pressure built up in the transverse branch pipe connected to said C-shaped pipe.

According to the invention, it will be understood that a C-shaped pipe functions to vent upper and lower portions of said vertical drain pipe, thereby eliminating pressure variation which tends to expel sealing water in a water trap.

An advantage of the installation described above is that it is equivalent to conventional ones in its drainage performance without any need for the aforementioned vertical vent pipe and loop tubes.

The structural simplicity of this drainage installation will make it possible to shorten the construction period and to reduce the construction cost.

Claims (4)

1. A drainage installation in a multi-storey building which installation comprises a main downwardly extending drain pipe provided at each storey with a by-pass pipe connected at each of its ends to the main drain tube and connected through one or more branch pipes to sanitary fixtures on its respective storey.

2. An installation as claimed in claim 1 wherein the or each branch pipe is connected to a substantially vertical run of its respective by-pass pipe.

3. An installation as claimed in claim 1 or claim 2 wherein the by-pass pipes are substantially C-shaped.

4. A drainage installation substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.