Device for flushing out the pipework of a building water-supply system
The invention concerns a device for flushing out the pipework of a building water-
supply system, comprising a float control means that actuates a filling vaive in the
inflow line which filling valve is connected to the building water-supply system by
means of a water-supply pipe and an angle valve and that is fitted with a drain
valve that can be actuated by means of a mechanical or electronic actuating unit,
wherein the drain valve incorporates an overflow hole that leads into a drain hole.
Devices for flushing out the pipework of building water-supply systems are used to
prevent microbial contamination of water standing in the pipework. It is also known
that besides flushing out the pipework microbial contamination can be prevented
by chemical or thermal processes. The invention described here relates solely to
the flushing out of pipework. Microbial contamination is caused when water stands
for a longer period of time through longer non-use.
A large number of different means of flushing out pipework in building water-
supply systems is known. For example, known from DE 10 2006 017 807 A1 is a
method of providing in a drinking-water-supply system with various draw-off points
an additional tapping point that incorporates a valve that is connected to a control
means. When the valve is opened and if within a set period of time a sensor
detects that no water has been drawn off at the draw-off points, a cleaning flush is
actuated. The water drawn off through the valve to actuate a cleaning flush is
drained away into the drainage system by way of a drain assigned direct to the
valve so that any germs that may be in the water cannot find their way into the
water used for drinking. Although the known method fulfils the requirements, it is
very expensive and effortful because an additional tapping point and a separate
drain have to be provided for during the planning and installation of the building
water-supply system. Later installation requires considerable additional expense
because of the additional draw-off point and connection to the drainage pipes.
Known from DE 10 2008 047 938 A1 is a drinking water pipework system in which
flush-cleaning is possible without having to provide for an additional draw-off point.
Rather flushing is actuated by actuating WC or urinal flushing. Here it is necessary
to provide the WC or urinal installation with an electronic flushing valve fitting

having a magnetic or motor-powered drain valve. The control means for
determining regular water draw-off operates with a sensor arranged in the
installation. The water drawn off for the purposes of flush-cleaning is drained away
into the drainage system by way of the WC or urinal bowl so as to ensure that the
water possibly infected with germs does not enter the water used for drinking. The
known drinking water pipework also fulfils the requirements made. However, it
requires the WC or urinal valve fitting to be constructed as an electronic valve
fitting right at the pipework planning stage. The retrofit of a non-electronic flushing
system or a flushing valve fitting with electronic flushing components is very costly
and time-consuming and particularly in the case of in-wall flushing cisterns as
good as impossible.
With the known systems the pipework of building water-supply systems that link
together individual consumers, what is known as basic pipework, is flushed out. To
flush out the piping running from the basic piping to the fitting connection modern,
valve fittings to carry out what is known as "hygienic or 24-hour flushing" are
normally fitted. With this system after a pre-set time during which the valve fitting
is not used a short water draw-off corresponding to at least the volume of standing
water between the basic pipework and the fitting is actuated.
Another device is known from DE 20 2011 105 696 U1. This device is mounted in
a flushing cistern. The sensor used in the device is a flow sensor, which is placed
directly before the filling valve. This kind of monitoring considers only flushing of
the cistern, wherein the sensor is mounted. It is not able to monitor flushing of
other extraction points in the same line section. Therefore, it is necessary to
provide sensors at every extraction point to enable the device to monitor the line
section in its entirety.
Based on the facts set out in the foregoing, the invention described here is based
on the problem of creating a device for flushing out the pipework of a building
water-supply system that is, on the one hand, suitable for the use of manually and
electronically powered water draw-off points and, on the other, enables retrofitting
into an already existing building water-supply system. This problem is solved by
the invention in that it provides for one or more branch pieces in the inflow line that
links or link a valve and/or a sensor to the building water-supply system and that

the sensor is able to detect any draw-off of water from the building water-supply
system.
By the invention a device for flushing out the pipework of a building water-supply
system is created that enables retrofitting at already existing draw-off points. At
the same time the device is suitable for use both on existing manually actuatable
fittings as well as on electronically actuatable fittings. The sensor is able to
determine the normal use of the fitting concerned and transmit this information to
the control means.
In further development of the invention the valve is an electrically powered valve.
The use of an electrically powered valve has the advantage of enabling faster
control means.
The valve preferably incorporates an outlet connection socket that is positioned
at a shortest possible distance from the overflow hole. The shortest possible
distance conforms to the shortest possible distance between the valve outlet and
highest possible water level as prescribed by DIN EN 1717. The shortest possible
distance prevents the water from being sucked back.
The sensor should preferably be pressure sensor. Such sensors are able to detect
pressure variations very sensitive and send correlated signals to control means
that can activate suitable actions.
In one embodiment of the invention the filling valve, the drain valve, the angle
valve and the valve are fitted in a flushing cistern, The device according to the
invention is in this case suited for a WC flushing system, including for in-wall
fitting.
In another embodiment of the invention the control equipment takes the form of a
float. This embodiment is selected for use in a normal flushing cistern.
Consequently combination with the device according to the invention is possible
for retrofitting in already installed flushing cisterns.

In a further embodiment of the invention one or more additional inflow lines is or
are provided for. Because of this the device according to the invention can be
installed without altering the inflow line originally provided for.
The problem is further solved according to the invention by a device for flushing
out the pipework of a building water-supply system on which device the filling
valve is a magnetic valve and the float control means is constructed as a sensor
for determining the filling level. This enables completely electronic actuation of the
, monitoring and flushing systems. It does not incorporate any mechanical, moving
parts and is especially suited for retrofitting.
The filling valve is preferably a magnetic valve. The use of a magnetic valve
enables the flushing cistern to be filled considerably faster than is the case with
the float control normally provided for. This is to be especially desired in operating
conditions in which the WC flushing system concerned is in frequent use, for
example, in stadiums or event locations.
Other developments and embodiments of the invention are set out in the
remaining subclaims. Practical embodiments of the invention are shown in the
drawings and are described in detail below. The following are shown in the
drawings:
Figure 1 a basic view of a mechanically actuated device fitted into a flushing
cistern;
Figure 2 a basic view of a mechanically actuated device fitted into a flushing
cistern in another embodiment and
Figure 3 a basic view of an electronically actuated device fitted into a flushing
cistern.
Those devices for flushing out the pipework of a building water-supply system that
are selected as example embodiments are all fitted into a flushing cistern 1.
However the invention is not restricted to installation inside the flushing cisterns of
WC systems. Rather they may also be used at other water draw-off points in the
building water-supply system, for example, in urinals, wash basins, bidets or sink
units.

The device according to the invention comprises a float control means 9 that
actuates a filling valve 2 in the inflow line to the draw-off point. The drawn off
water is drained away into the drainage system by means of the WC bowl. The
device incorporates an angle valve 4, 104, 204 by means of which the water inflow
line into the flushing cistern 1 can be shut off. A magnetically controlled valve 5,
105, 205 is provided for that is connected to a control means 6, 106, 206. In the
example embodiments shown in figures 2 and 3 a sensor 107, 207, which may be,
for example, a pressure sensor, is arranged in the device.
The flushing cistern 1 incorporates a drain connection socket 10 that can be
connected to a flushing pipe (not shown) that is connected to the WC bowl.
Constructed in the drain connection socket 10 is a drain hole 11. The drain
connection socket 10 is provided with a seal 12 on the outside of its free end.
Formed round about the drain hole 11 at the bottom of the flushing cistern 1 are
guide fins 13 that serve as a seat for the drain valve 3. Constructed in the flushing
cistern 1 is a fitting aperture 14, here indicated only schematically by a dot-dashed
line in figures 1 to 3.
The drain valve 3 incorporates a lifting sleeve 30. An overflow hole 31 is provided
for that extends to the bottom of the flushing cistern 1 and is there continued by
the drain hole 11. The overflow hole 31 enables the water to run out of the flushing
cistern, even if the drain valve 3 is closed. The drain valve 3 also incorporates a
curved rod 32 on which the float-controlled rod of a manually actuatable actuating
mechanism is arranged. In the area of the bottom of the flushing cistern 1 the
drain valve 3 is fitted with a seal 33.
The angle valve 1 forms the transition point of the water inflow line from the
building water-supply piping into the flushing cistern 1. The angle valve 4, 104,
204 is provided with a control knob 40, 140, 240. It incorporates a water-supply
screw connection 41, 141, 241 to which a water-supply connection pipe 48, 148,
248 is screwed. At a point in the water-supply connection pipe 48, 148, 248 a
branch piece 42, 142, 242 is provided for. The branch piece 42, 142, 242 is, on
the one hand, connected to a water-supply connection pipe 43, 143, 243 and, on
the other, in the example embodiment shown in figures 1 and 2 connected by

means of a water-supply screw connection 45, 145 to a water-supply connection
pipe 44, 144 for connection to the water-supply connection socket 23 of the filling
valve 2. In the example embodiment shown in figure 3 the branch piece 242 is
connected to the sensor 207. The water-supply connection pipe 43, 143, 243 is
screwed to the valve 5, 105, 205 by means of a water-supply screw connection
46, 146, 246.
The valve 5, 105, 205 is fitted with an outlet connection socket 50, 150, 250. It is
connected to the control means 6, 106, 206 by means of a water-supply
connection pipe 60, 160, 260. In the example embodiments shown in figure 2
and 3 the control means 106, 206 is connected to the sensor 107, 207 by means
of a water-supply connection pipe 161, 261. In the example embodiment shown in
figure 3 the control means 206 is also connected by means of a water-supply
connection pipe 262 to the control equipment 8 constructed in the form of a sensor
for determining the filling level.
The float control means 9 in the example embodiments shown in figures 1 and 2
actuates the filling valve 2. It is constructed in the form of a float on which a guide
tube 80 is attached. Provided for adjacent to the guide tube 80 is a valve rod 81
for actuating the filling valve 2. In the example embodiment shown in figure 3 the
sensor is provided for to determine the filling level. Connected to the sensor is an
immersion tube 81 to determine the level of the filling in the flushing cistern 1. The
filling level is monitored by the filling level sensor 8. During measurement the filling
level is recorded steplessly and converted to an electric signal. The filling level
sensor 8 can operate capacitively by means of microwaves or the like.
Then example embodiment shown in figure 1 represents the least effortful and
least expensive design for a device for flushing out a building water supply
system. The only difference between this design and that of the normally
mechanically actuated flushing cisterns for WC flushing consists in the fact that
the magnetically controlled valve 5 and the control means 6 are retrofitted. It is
also necessary to interrupt the water-supply connection pipe 44 that on
conventional flushing cisterns connects the angle valve 4 with the filling valve 2
direct, to provide for the branch piece 42 and so to enable the water to be drawn
off the building water-supply system from a point outside the flushing cistern. This

is done at the end of the time interval set in the control means 6. As soon as this
time interval has elapsed, the control means 6 sends a signal to open the
magnetically controlled valve 5. Consequently, water can enter the flushing
cistern 1 by way of the angle valve 4 and flow through pipes 48 and 43 through
the valve 5 and its outlet connection socket 50 into the flushing cistern. This
causes the filling level in the flushing cistern 1 to rise. However, because of the
overflow hole 31 provided for in the drain valve 3 there is no risk of damage to the
WC flushing system. Rather the water entering the flushing cistern runs out of the
flushing cistern 1 through the overflow hole 31 and flows through the drain hole 11
in the direction of the WC bowl.
A comparable procedure with regard to the function of the valve 105, 205 is
followed in the example embodiments shown in figures 2 and 3. In the example
embodiment in figure 2, in which likewise a mechanically actuated WC system is
shown, an extended solution is provided in which in addition to the retrofittable
valve 105 and the retrofittable sensor 106 a retrofittable sensor 107 is provided for
that is connected to the control means 106 and connected to the water-supply
connection pipe 148 by way of the branch piece 147. The sensor 107 detects
draw-off of water when the WC flushing system is operated. It signals such water
draw-off to the control means 106. Because of this signal to the control means 106
the time interval set in the control means 106 is re-started. If the sensor 107 has
not detected any water draw-off within the specified time interval and
consequently not sent a signal to the control means 106, the control means 106
sends a signal to open the magnetically controlled valve 105. Consequently, water
can enter the flushing cistern 1 by way of the angle valve 104 and flow through
pipes 148 and 143 through the valve 105 and its outlet connection socket 150 into
the flushing cistern. Outflow from the flushing system 1 takes place in the manner
described with regard to the example embodiment shown in figure 1.
In the example embodiment shown in figure 3 the device for flushing out the
pipework in a building water-supply system is arranged in an electronically
actuatable WC flushing system. In this embodiment, as in the example
embodiment shown in figure 2, the sensor 207 detects a draw-off of water and
transmits the detected water draw-off to the control means 206. At the end of a

pre-set time interval the control means 206 sends a signal to open the
magnetically controlled valve 205 to enable flushing out of the pipework.
By the invention a device for flushing out the pipework of a building water-supply
system is created that can be retrofitted. As can be seen from the example
embodiments, the required component parts, if not already available, can be fitted
into the flushing cistern without a problem. Particularly the example embodiment
shown in figure 1, in which only the control means 6 and the valve 5 with its
connection to the piping system need be retrofitted, represents a very simple and
at the same time reliable means of preventing germs from collecting in standing
water. As can be seen, the component parts can also be fitted into the in-wall
flushing system through the fitting aperture 14. The same applies to the example
embodiments shown in figures 2 and 3, although here because of the additional
use of the sensor 107, 207 slightly more fitting work is to be carried out.
Preferably, the sensor 107, 207 is a pressure sensor. This kind of sensor is able to
detect pressure variations very sensitive and send correlated signals to control
means 106, 206. The pressure variation by draw-off of water from the flushing
cistern 1 wherein the sensor 107, 2017 is mounted is different to the pressure
variation that is detected, if a draw-off of water takes place at another extraction
point. The differences between rise and decline of the pressure are deposited in
the control means 106, 206. Therefore, the control means 106, 206 can activate
suitable actions dependent from the signals that were sent by the sensor 107,
207. Consequently, the invention provides a system that is able to control the
entire line section by only one sensor 107, 207, integrated in the flushing cistern 1.
Therefore, the costs for retrofitting a control system into an already existing
building water-supply system. Already known devices need more than one sensor,
namely one sensor at every extraction point of the same line section.
Fitting itself is also guaranteed through the fitting aperture 14 in the in-wall
flushing system, so that here too problem-free retrofitting is possible. In a variant
of the example embodiments shown in the figures one or more additional inflow
lines can be provided for. This enables, for example, the branch piece 42, 142 to
be dispensed with.

Claims
1. Device for flushing out the pipework of a building water-supply system,
comprising a float control means (9) that actuates a filling valve (2) in the inflow
line which filling valve is connected to the building water-supply system by means
of a water-supply connection pipe (44, 144) and an angle valve (4, 104, 204) and
that is fitted with a drain valve (3) that can be actuated by means of a mechanical
or electronic actuating unit, wherein the drain valve (3) incorporates an overflow
hole (31) that leads into a drain hole (11), characterized in that one or more
branch pieces (42, 142, 242, 147) that connects or connect a valve (5, 105, 205)
and/or a sensor (107, 207) to the building water-supply system is or are provided
for in the inflow line and that the sensor (107, 207) is able to detect water draw-
off from the building water-supply system.
2. Device in accordance with claim 1, characterized in that the branch piece (42,
142, 242, 147) is arranged between the filling valve (2) and the angle valve
(4,104,204).
3. Device in accordance with claim 1 or 2, characterized in that the valve (5, 105,
205) is an electrically powered valve.
4. Device in accordance with any one of the foregoing claims, characterized in that
the valve (5, 105, 205) incorporates an outlet connection socket (50, 150, 250)
that is positioned at a shortest possible distance (x) from the overflow hole (31).
. 5. Device in accordance with any one of the foregoing claims, characterized in that
a control means (6, 106, 206) is provided for to control the valve (5, 105, 205).
6. Device in accordance with any one of the foregoing claims, characterized in that
the sensor (107, 207) is a pressure sensor.

7. Device in accordance with any one of the foregoing claims, characterized in that
the filling valve (2), the drain valve (3) the angle valve (4, 104, 204) and the valve
(5, 105, 205) are fitted into a flushing cistern (1).
8. Device in accordance with any one of the foregoing claims, characterized in that
one or more additional inflow lines is provided for.
9. Device for flushing out the pipework of a building water-supply system,
comprising a float control means (9) that actuates a filling valve (2) in the inflow
line which filling valve is connected to the building water-supply system by means
of a water-supply pipe (44, 144) and an angle valve (4,104,204) and that is fitted
with a drain valve (3) that can be actuated by means of a mechanical or
electronic actuating unit, wherein the drain valve (3) incorporates an overflow
hole (31) that leads into a drain hole (11), characterized in that the filling valve (2)
is a magnetic valve (205) and the float control means (9) is in the form of a
sensor to determine the filling level.
10. Device in accordance with claim 9, characterized in that the float control means
(9) is in the form of a filling level sensor (8).
11. Device in accordance with claim 9 or 10, characterized in that the valve (205)
incorporates an outlet connection socket (250) that is positioned at a shortest
possible distance (x) from the overflow hole (31).

12. Device in accordance with any one of the foregoing claims, characterized in that
a control means (206) is provided for that is connected to the valve (205 and the
filling level sensor (8).
13. Device in accordance with any one of the foregoing claims, characterized in that
one or more additional inflow lines is provided for.