[0001] The invention relates to a tubular coupling piece, particularly for use in a pipe
system of a ventilation or flue gas discharge channel, and to an assembly of a coupling
piece and pipe segment. The invention also relates to a branch pipe for use with such
a coupling piece, for instance for connecting thereto a combustion device in the case
of a pipe system operating as flue gas discharge channel, or for instance a ventilation
device or ventilation grille in the case of a pipe system operating as a ventilation
channel.
[0002] Separate or combined ventilation and flue gas discharge channels are installed in
practice for ventilation purposes, such as for instance for supplying and/or discharging
fresh air to and/or from a space, for discharging flue gases from heating devices
or other combustion devices such as ovens, and for instance for supplying combustion
air thereto.
[0003] Such ventilation and flue gas discharge channels are constructed nowadays from plastic
or metal tubes or pipes, such as tubes or pipes of polypropylene, aluminium or stainless
steel. The pipe material to be selected depends here on, among other factors, the
type of combustion device, i.e. the type of combustion material such as gas, oil or
wood, the final temperature of the flue gas to be discharged, which in higher efficiency
devices will be lower than in the case of lower efficiency devices, and the degree
of condensation in the pipe system.
[0004] Particularly in older buildings these ventilation and flue gas discharge channels
may still consist of brickwork or concrete or other stone or ceramic shafts or chimneys,
or ventilation or flue gas discharge shafts assembled from galvanized pipes. Particularly
because of condensation on the pipe wall due to, among other factors, water vapour
in the flue gas or in the air to be discharged from shower areas or bathrooms or other
moist spaces, these galvanized pipes are highly susceptible to corrosion, whereby
leakages occur in the pipe system after a period of time. In the case of a flue gas
discharge system such leakages can result in potentially dangerous situations, since
components present in the flue gas, such as nitrogen dioxide, carbon dioxide, carbon
monoxide and sulphur dioxide, can be released in the building instead of being discharged
to the outside via for instance a discharge or chimney flue on the roof of the building.
[0005] Also in the case an older combustion device is replaced by a more modern appliance
it may be necessary, for instance on the basis of the composition and temperature
of the flue gas to be discharged, to replace the existing flue gas discharge system
by a pipe system constructed from materials better suited to the purpose. Such modern
combustion devices have a relatively low flue gas temperature compared to older devices,
although this is associated with a greater degree of condensation in the pipe system.
The lower flue gas temperature does on the other hand make it possible however to
construct the flue gas discharge system wholly from a plastic material.
[0006] In order to avoid cutting and breaking work as much as possible during replacement
or renovation of existing installation and flue gas discharge channels, pipe systems
constructed from mutually coupled pipe segments are arranged where possible in practice
as ventilation and/or flue gas channels in the existing ventilation and flue gas discharge
shafts. Not only ventilation and flue gas discharge channels to be replaced but also
those to be newly installed are constructed in practice in the form of pipe systems
assembled from mutually coupled pipe segments.
[0007] Tubular coupling pieces, also referred to as sleeves, are usually applied for coupling
the pipe segments in longitudinal direction. In order to prevent pipe segments being
received too far into a coupling piece during installation in a shaft, or even passing
wholly through a coupling piece, these coupling pieces are provided internally with
one or more stops, such as ribs or the like, running around the peripheral wall.
[0008] An example of such a pipe system is described in, among others, the non-prepublished
Netherlands patent application, filed simultaneously with the present patent application
in the name of applicant, with the title: "Pipe system, coupling piece and method
for installing the pipe system in a shaft of a building". In an embodiment of this
pipe system the tubular coupling pieces are provided with at least one connecting
opening for connection thereto of a branch pipe or branch pipe part. The branch pipe
then leads to an appliance to be connected to the pipe system. The stop or stops formed
in this coupling piece serves or serve the purpose, among others, that the connecting
openings cannot be blocked by a pipe element received in the coupling piece.
[0009] As already noted in the foregoing, during use of the pipe system fluid formation
occurs along the inner wall thereof, for instance in the form of condensate as a result
of the formation of vapour, such as water vapour, in air to be discharged or in flue
gas or other combustion emission products to be discharged. During operation this
condensed fluid or condensed liquid, such as condensed water or other liquid composition,
flows downward in the pipe system under the influence of gravitational force. A part
of the condensed fluid will of course also evaporate again and be discharged with
the flue gas when sufficiently hot flue gas is for instance discharged from a flue
gas discharge connected to the pipe system.
[0010] The liquid or fluid draining downward along the peripheral wall of the pipe segments
and the coupling pieces, in the case of a pipe system used as flue gas discharge channel
or as ventilation channel, is however blocked by the stop or stops formed in a coupling
piece and will accumulate at such a stop. Particularly when the coupling piece and/or
the pipe system does not run truly vertically, there is the risk that all the fluid
such as water which has accumulated at the stop will flow in uncontrolled manner to
a connected device or to a ventilation grille or the like. This can cause malfunction
of a device or for instance damage caused by water dripping out of a ventilation grille.
[0011] German patent application DE 43 12 094 A1 and the
British patent application GB 2 415 033 disclose a tubular coupling piece particularly for use in a pipe system of a ventilation
or flue gas discharge channel, which coupling piece has an inlet end and an outlet
end for connection to a pipe segment of the pipe system and wherein the coupling piece
is provided in its peripheral wall between the inlet end and the outlet end with at
least one connecting opening for connection of a branch pipe thereto, wherein the
coupling piece is further provided with a stop for a pipe segment extending internally
over a distance in radial direction around the peripheral wall, which stop is embodied
as fluid collection channel for collecting fluid moving during use along the peripheral
wall in the coupling piece, wherein the fluid collection channel connects to the at
least one connecting opening.
[0012] By embodying the or each stop in the coupling piece as fluid collection channel fluid
draining along the peripheral wall in the coupling piece is collected during use in
the collection channel even when the coupling piece or the pipe system is not installed
truly vertically. This fluid collection channel can for instance consist of an approximately
U-shaped peripheral channel, the open side of which is directed toward the inlet end
of the coupling piece. Having the fluid collection channel also connect to a connecting
opening achieves that the collected liquid can, if desired, be discharged via a branch
pipe or branch pipe part connected to the connecting opening and a device, such as
a combustion device, connected thereto. Modern combustion devices do after all generally
themselves have a discharge for discharging, for instance via a sewer connection,
condensed fluid formed in the device. A problem then however occurs when the collected
fluid or condensate may not or cannot drain via the connecting opening.
[0013] The invention has for its object to provide a solution for the purpose of allowing
fluid, such as condensed fluid, collected by a fluid collection channel to also drain
in a controlled manner when the connecting opening is closed or when collected fluid
may not be discharged via the connecting opening and a branch pipe connected thereto.
[0014] This object is achieved by the invention in that the fluid collection channel debouches
into the at least one connecting opening and the part of the fluid collection channel
debouching into the at least one connecting opening is provided with a fluid throughflow
channel connecting internally to the peripheral wall of the coupling piece for the
purpose of draining through the coupling piece fluid collected by the fluid collection
channel.
[0015] For guided discharge of fluid from the fluid collection channel according to the
invention, the part of the fluid collection channel debouching into the connecting
opening is provided with a fluid throughflow channel connecting internally to the
peripheral wall of the coupling piece and having a fluid throughflow opening for the
purpose of draining through the coupling piece fluid collected by the fluid collection
channel.
[0016] In the case that fluid collected in the fluid collection channel may not or cannot
be discharged via a branch pipe connected to a respective connecting opening and a
device connected thereto, such as a combustion device, the solution according to the
invention thus provides the option of guiding the collected fluid via the fluid throughflow
channel or fluid overflow channel back into the coupling piece.
[0017] Such a situation can for instance occur when the connected device does not have its
own condensation discharge, or for instance in the case of a ventilation grille or
the like.
[0018] Another situation is that where a connecting opening is not or not yet being used
and for instance is closed to the outside by means of a cover or cap. Without fluid
throughflow channel or fluid overflow channel the fluid collecting in the collection
channel would accumulate at the cover, whereby for instance a sealing gasket of the
cover which is in contact with the fluid could in time be adversely affected by the
aggressive substances in the condensed fluid. The fluid throughflow channel prevents
such an accumulation in that the fluid is guided back into the coupling piece and
for instance discharged via a combustion device lying below or for instance via a
condensation outlet connected to the lowest coupling piece.
[0019] In an embodiment of the invention is the fluid collection channel arranged, as seen
in the direction from the inlet end to the outlet end of the coupling piece, at the
bottom of the connecting opening and connects thereto. That is, the fluid collection
channel is open from the connecting opening. The dimensions of the channel, i.e. the
collecting volume thereof, can be adjusted to the extent of expected condensation.
A channel will generally suffice with a width and height of for instance 5-10 mm.
[0020] In yet another embodiment of the invention the fluid throughflow channel is provided
in the direction towards the peripheral wall of the coupling piece with a fluid flow
resistance. Such a fluid or liquid flow resistance achieves that the collected fluid
is preferably discharged in the first instance via a connected branch pipe. Only from
a certain level will collected fluid also be able to flow back into the coupling piece
via the fluid throughflow channel. The quantity of fluid flowing into the branch pipe
can be adjusted by adjusting the flow resistance.
[0021] When for instance a connecting opening is closed as described above, the flow resistance
ensures that, as soon as fluid begins to flow back into the coupling piece, a certain
flow of fluid also occurs in the fluid collection channel, whereby the fluid in the
collection channel is 'refreshed', resulting in no or far fewer aggressive substances
remaining behind in the fluid collection channel than without such a flow.
[0022] In an embodiment the fluid flow resistance is formed by the fluid throughflow channel
rising from the part of the fluid collection channel debouching into the connecting
opening to the peripheral wall of the coupling piece. The fluid throughflow channel
preferably rises here with a uniform inclination.
[0023] In a further embodiment of the coupling piece, wherein the fluid collection channel
debouches into the connecting opening over a distance transversely thereof, for instance
in the form of a spout, the fluid throughflow channel or fluid return flow channel
is arranged in the debouchment.
[0024] For connection of a branch pipe to a connecting opening the coupling piece is provided,
in an embodiment, with a tubular flange protruding outward over a distance transversely
of the peripheral wall of the coupling piece, wherein the fluid collection channel
is formed over a distance along the flange and connects thereto.
[0025] For further controlled drainage of possibly surplus fluid from the fluid collection
channel via a branch pipe according to the invention, in yet another embodiment, the
flange is formed inclining in the direction of the outlet end of the coupling piece.
The angle of inclination relative to the normal to the peripheral wall of the coupling
piece amounts, in this embodiment, to only a few degrees.
[0026] In order to prevent leakage of fluid from the connection of a branch pipe to the
coupling piece the flange is provided on its outer periphery with at least one sealing
ring so that the at least one sealing ring engages fluid-tightly on the inner periphery
of a branch pipe to be arranged over the flange.
[0027] In an embodiment the flange is provided with attaching members for attaching a branch
pipe or branch pipe part releasably to the coupling piece. Such as for instance attaching
members in the form of a screw coupling.
[0028] An embodiment as screw coupling has the advantage that the force required to slide
a branch pipe over the sealing ring or gasket on the outer periphery of the flange,
which force can be relatively great in the case of a coupling piece received in a
flue gas discharge channel because it is precisely here that an exceptionally good
fluid-tight seal is essential, can be generated relatively easily by means of a screwing
movement.
[0029] In an embodiment as screw coupling the attaching members comprise at least a first
and second nose-shaped member protruding outward from the peripheral wall of the coupling
piece, which nose-shaped members are disposed opposite each other at a distance from
the flange adjacently thereof, with a connecting groove facing toward the flange for
receiving therein a radially outward protruding connecting lip of a branch pipe to
be arranged over the flange.
[0030] The connecting lip of the branch pipe and the connecting groove in the attaching
members form a fitting screw thread connection in the form of a bolt/nut connection,
the attaching members of which form the nut part and the branch pipe the bolt part.
[0031] In a further embodiment the screw coupling is embodied as self-positioning screw
coupling, wherein an end of a branch pipe for use with a coupling piece is formed
for receiving the flange therein, wherein the radially outward protruding connecting
lip is a single helical revolving connecting lip with a pitch distance such that,
when the revolving connecting lip is placed against the nose-shaped members and in
this position the branch pipe is then rotated, the connecting lip engages automatically
in the connecting grooves of the nose-shaped members.
[0032] Such a self-positioning screw coupling facilitates the connection of a branch pipe
to the coupling piece, particularly in the case of connections at locations which
are difficult to access, or for instance a connection via an opening in an existing
shaft.
[0033] In a further embodiment the revolving connecting lip takes a resilient form over
a distance in axial direction of the branch pipe such that at the position of this
resilient part the pitch distance of the revolving connecting lip differs.
[0034] During connection to the coupling piece, after screwing or rotating of the branch
pipe beyond a connecting groove of a nose-shaped member, this resilient part forms
a discernible indication that the branch pipe has been screwed a sufficient distance
over the flange, and also forms a barrier, in the form of a safety catch, against
loosening of the branch pipe due to vibrations or temperature fluctuations or the
like.
[0035] A similar effect is obtained with another embodiment of the branch pipe wherein the
revolving connecting lip takes a resilient form over a distance in radial direction
of the branch pipe such that at the position of this resilient part the connecting
lip protrudes further outward in radial direction than the remaining part of the revolving
connecting lip.
[0036] Such a screw coupling provides for a safe and mechanically secure connection of a
branch pipe to a coupling piece.
[0037] In an embodiment the invention also provides a cover for fluid-tight closure of a
connecting opening, this cover corresponding in respect of the part to be connected
to the coupling piece to the end of the branch pipe to be connected to the connecting
opening, and wherein the other end of the branch pipe is closed.
[0038] In the case that a device for connection is for instance not suitable for condensation
discharge, according to the invention the internal diameter of the part of the branch
pipe not engaging on the flange is smaller than the internal diameter of the flange.
This creates an effective barrier to condensation discharge via the branch pipe so
that the fluid collected in the fluid collection channel flows via the fluid throughflow
channel back into the coupling piece. The branch pipe can of course be provided, with
the same effect, with an internal radially protruding elevation or the like which
acts as barrier to condensation discharge via the branch pipe. This can in fact also
be interpreted however as a reduction in the diameter of the branch pipe as described
above.
[0039] In an embodiment of the invention, the fluid collection channel is formed as double-sided
collection channel for collecting both from the inlet end and from the outlet end
fluid moving along the peripheral wall during use.
[0040] In an embodiment the invention also provides an assembly of a coupling piece and
a pipe segment connected fixedly to each other, particularly wherein the pipe segment
and the coupling piece are welded together.
[0041] The invention is now elucidated by way of example in more detail with reference to
the accompanying figures. The invention is by no means limited to the embodiment of
the invention shown in the figures. The same or similar elements also have the same
reference numerals in the figures.
Figure 1 shows schematically and in partial cross-section a pipe system provided with
coupling pieces according to an embodiment of the invention and installed in a flue
gas discharge shaft of a building consisting of multiple storeys.
Figure 2 shows schematically and in perspective on enlarged scale a cylindrical tubular
coupling piece of the pipe system according to an embodiment of the invention shown
in figure 1.
Figure 3 shows schematically and in perspective a cross-section of the coupling piece
along the line III-III in figure 2.
Figure 4 shows a schematic, partially cross-sectional view along the line IV-IV in
figure 2.
Figure 5 shows schematically and in perspective on enlarged scale a detail of the
coupling piece as shown in figure 2 with connecting opening and a branch pipe to be
attached thereto.
Figure 6 shows schematically and in perspective on enlarged scale a cover for closing
a connecting opening of the coupling piece as shown in figure 2.
[0042] Shown schematically in figure 1 is a flue gas discharge system 10 of a building consisting
of multiple storeys 11, 12. Arranged in the flue gas discharge shaft 14 is a pipe
system 15 which in the shown example and as seen in the direction from the ground
floor 11 to the roof 13 comprises a first cylindrical pipe segment 25, a second cylindrical
pipe segment 26 and a third cylindrical pipe segment 27 which have connecting thereto
in each case a first cylindrical tubular coupling piece 28, a second cylindrical tubular
coupling piece 29 and a third cylindrical tubular coupling piece 30 located at a distance
from each other in longitudinal direction in the flue gas discharge shaft 14.
[0043] The first pipe segment 25 is received fitting with an end in the first coupling piece
28 and received fitting with another end in the second coupling piece 29. The second
pipe segment 26 is received fitting with an end in the second coupling piece 29 and
received fitting with another end in the third coupling piece 30. The third pipe segment
27 is received fitting with an end in the third coupling piece and the other end of
the third pipe segment 27 ends on the roof 13 of the building in an end 19 of the
pipe system 15 which is open to the outside air.
[0044] The first and second coupling pieces 28, 29 are attached to each other by an elongate
connecting element 31 extending in longitudinal direction of the first pipe segment
25. The second and third coupling pieces 29, 30 are attached to each other via an
elongate connecting element 32 extending in longitudinal direction of the second pipe
segment 26, and extending from the third coupling piece 30 in longitudinal direction
of the third pipe segment 27 in the direction of the roof 13 is a third elongate connecting
element 33, which is attached to the roof. The pipe system 15 thus consists here of
a cascade of pipe segments 25, 26, 27 and coupling pieces 28, 29, 30 freely suspended
in the flue gas discharge shaft 14, this in accordance with the non-prepublished Netherlands
patent application filed simultaneously with the present patent application in the
name of applicant with the title "Pipe system, coupling piece and method for installing
the pipe system in a shaft of a building".
[0045] Located on the ground floor 11 in the shown embodiment of the pipe system are two
combustion devices 17, 18, such as a central heating boiler and/or a hot water appliance,
the flue gas discharge of each of which are connected via a branch pipe or branch
pipe part 20, 21 to the first coupling piece 28. Situated on the first floor 12 of
the building in the shown embodiment is a single combustion device 16 which is connected
via a branch pipe 22 to the third coupling piece 30. No devices are connected to the
second coupling piece 29. This coupling piece functions solely for the purpose of
connecting the first and second pipe parts 25, 26.
[0046] Although the combustion devices 16, 17, 18 are all shown mounted at the same height,
it should be understood that these devices and their branches 19, 20, 21 to a respective
coupling piece 28, 30 on the various floor levels 11, 12 can be located at different
heights. Although not shown, the end 23 of the pipe system 15 can be connected to
an outlet for discharging fluid collected in the pipe system 15, such as condensed
water from flue gas to be discharged. Instead of installation in an existing flue
gas discharge shaft 14, the pipe system 15 can of course also be applied in new building
projects.
[0047] One or more of the combustion devices 16, 17, 18 can be provided with its own condensation
outlet to, for instance, the sewer (not shown).
[0048] Although a pipe system is shown in figure 1 as flue gas discharge channel, it should
be appreciated that the pipe system 15 can also be used as ventilation channel, wherein
the devices 16, 17, 18 are for instance air discharge devices or air grilles.
[0049] The first, second and third coupling pieces 28, 29, 30 may substantially each be
of differing form. From the viewpoint of costs and convenience of mounting it is advantageous
to couple the pipe segments to each other by means of a uniform coupling piece and
to connect the various devices hereto via a uniform branch pipe part.
[0050] Figure 2 shows by way of example on enlarged scale the third tubular coupling piece
30 shown in figure 1. The coupling piece 30 has a cylindrical, tubular and elongate
peripheral wall 36 which extends between an inlet end 34 and an outlet end 35 of the
coupling piece. The inlet end 34 and the outlet end 35 are suitable for receiving
therein a pipe segment of the pipe system 15, such as respectively the third 27 and
second pipe segment 26 as shown in figure 1.
[0051] Arranged for the purpose of attaching the coupling piece 30 to an attaching element
32, 33 are attaching elements 37, 38 located externally on the peripheral wall 36
near the outlet end 35 and the inlet end 34. The attaching elements 37, 38 have in
the shown embodiment a strip-like or strip-shaped receiving slot 39 extending in longitudinal
direction of the coupling piece 30 for movably receiving therein and attaching a strip-like
or strip-shaped connecting element 31, 32, 33.
[0052] Between the inlet end 34 and the outlet end 35 the coupling piece 30 is provided,
in its peripheral wall 36, with first and second opposite connecting openings 40,
41 for connection of a branch pipe 20, 21, 22 thereto. In the shown embodiment the
branch pipe 22 is connected via a self-positioning releasable screw coupling 42 to
the connecting opening 40.
[0053] Between the inlet end 34 and the outlet end 35 the coupling piece 30 is provided
in its peripheral wall 36 with first and second opposite connecting openings 40, 41
for connection of a branch pipe 20, 21, 22 thereto. In the shown embodiment the branch
pipe 22 is connected via a self-positioning releasable screw coupling 42 to the connecting
opening 40.
[0054] Figure 3 shows a cross-sectional view along the line III-III in figure 2. Both connecting
openings 40, 41 are provided with a tubular flange 43 protruding a distance outward
transversely of the peripheral wall 36 of the coupling piece 30 for connection of
the branch pipe or branch pipe part 22.
[0055] As seen in the direction from the inlet end 34 to the outlet end 35 of the coupling
piece 30 an approximately U-shaped fluid collection channel 45 extending internally
in the coupling piece 30 over a distance in radial direction around the peripheral
wall 36 is situated at the bottom of the connecting openings 40, 41. The open side
46 of the fluid collection channel faces toward the inlet end 34 of the coupling piece
30 (see figure 2) and connects here to the connecting openings 40, 41 for the purpose
of collecting fluid moving during use along the peripheral wall 36 in the coupling
piece 30 and the connecting openings 40, 41 or a branch pipe 22 connected hereto.
The closed base side 47 of the fluid collection channel 45 forms a stop for preventing
a pipe element received in the coupling piece from the outlet end 35, such as the
second pipe element 26 shown in figure 1, from being able to block the connecting
openings 40, 41.
[0056] In order to prevent a pipe segment received from the inlet end 34 blocking the connecting
openings 40, 41 ribs 48 protruding radially along the peripheral wall are formed internally
in longitudinal direction of the coupling piece 30 at the position of the connecting
openings 40, 41.
[0057] In the embodiment as shown in figure 3 the fluid collection channel 45 debouches
approximately in the form of a spout in the connecting openings 40, 41. The spout-like
part 49 extends internally along the wall of the flange 43 over a distance transversely
of a connecting opening 40, 41, i.e. in axial direction of a branch pipe 22 to be
connected to the flange 43. The part 49 of the fluid collection channel 45 debouching
in the connecting opening 40, 41 is provided with a fluid throughflow opening 50 which
connects internally to the peripheral wall 36 of the coupling piece 30 via a fluid
throughflow channel 51. Via this fluid throughflow opening 50 and the fluid throughflow
channel 51 fluid collected in the collection channel 45 during operation, such as
condensed liquid, which cannot be discharged via a branch pipe 22, can be drained
in controlled, guided manner through the coupling piece 30 and, via a lower-lying
coupling piece or finally at the end 23 of the pipe system 15, be collected and/or
discharged (not shown).
[0058] The length of the debouching part 49 is shorter than the length of the flange 43
as measured transversely of a connecting opening 40, 41. When an connecting opening
which is not or not yet being used is closed with a cover, such as the connecting
opening 41 which is closed with a cover 44, space is left so that fluid collected
in the fluid collection channel 45 can be drained via the fluid throughflow opening
50 and the fluid throughflow channel 51 through the coupling piece 30.
[0059] Leakage of fluid along the connection of the branch pipe 22 and/or a cover 44 on
the flange 43 is hereby prevented in that the flange 43 is provided on its outer periphery
with at least one sealing ring 52 for fluid-tight engagement of the sealing ring 52
on the inner periphery of a branch pipe 22 or the cover 44 to be arranged over the
flange 43. Sealing rings 52 for fluid-tight closure of the mutually engaging flange
43 and the branch pipe 22 and the cover 44 are commercially available. In the shown
embodiment the sealing ring 52 is received in a groove or recess 57 in the outer periphery
of the flange 43.
[0060] Because the collected condensed fluid is drained via the fluid throughflow channel
51 in the coupling piece accumulation of fluid or liquid at the cover 44 is effectively
prevented and as a result there is no chance, or a greatly reduced chance, of the
sealing ring 52 being adversely affected by substances in the condensed fluid, this
resulting in a greatly reduced risk of leakage of flue gases and fluid along the connection
of the cover 44 to the flange 43.
[0061] The flanges 43 of the coupling piece 30 are formed inclining through a few degrees,
for instance between 2-10 degrees, in the direction of the outlet end 35 relative
to the normal to the outer periphery 36, as indicated in figure 4 with the angle α.
This achieves that collected fluid drains away in the first instance via a branch
pipe 22 connected to the flange 43.
[0062] As indicated in figure 4 with the angle β, the bottom of the fluid throughflow channel
or fluid return flow channel 51 inclines upward to some extent, i.e. upward as seen
in the plane of the drawing, from the fluid throughflow opening 50 in the direction
toward the peripheral wall 36 of the coupling piece. This incline forms a fluid flow
resistance with which the quantity of fluid flowing in the branch pipe and back into
the coupling piece can be adjusted. This flow resistance also achieves that, when
for instance a connecting opening is closed, flow also occurs in the fluid collection
channel 46 so that fluid residues do not accumulate herein. A rib or other flow resistance
can also be arranged in the fluid return flow channel 51 instead of an incline. The
angle of inclination β relative to the normal to the outer periphery 36 of the coupling
piece amounts in practice to about 3 degrees.
[0063] In the case that a device for connecting is for instance not suitable for condensation
discharge, an effective barrier against condensation discharge via the branch pipe
22 can be brought about by selecting an internal diameter of the part of the branch
pipe 22 not engaging on the flange 43 which is smaller than the internal diameter
of the flange 43, so that the fluid collected in the fluid collection channel 46 flows
via the fluid throughflow channel 51 back into the coupling piece 30. The branch pipe
22 can of course be provided, with the same effect, with an internal radially protruding
peripheral elevation 64 or the like which acts as barrier against condensation discharge
via the branch pipe 22, as shown schematically with broken lines in figure 4. This
of course such that, when a branch pipe 22 is connected to the flange 43, the fluid
throughflow opening 50 remains open on the side of elevation 64 for discharge of fluid
from the fluid collection channel 46 in the coupling piece 30.
[0064] Figure 5 shows on enlarged scale the screw coupling 42 of the branch pipe 22 to the
flange 43 of the connecting opening 40. Figure 6 shows on enlarged scale the cover
44. In the shown embodiment the screw coupling 42 is embodied as self-positioning
screw coupling and comprises attaching members formed by at least a first and second
nose-shaped member or body 53 protruding outward from the peripheral wall 36 of the
coupling piece 30, see figures 2, 4 and 5. These nose-shaped members 53 are disposed
opposite each other at a distance from the flange 43 adjacently thereof, with a connecting
groove 54 facing toward the flange 43 for receiving therein a radially outward protruding
connecting lip of a first end of the branch pipe 22 or the cover 44 to be arranged
over the flange 43.
[0065] The radially outward protruding connecting lip 55 takes the form of a single helical
revolving connecting lip along the outer periphery of the branch pipe 22 with a first
end 61 and second end 62 lying opposite each other at a pitch distance s. The pitch
distance s of the helical revolving connecting lip 55 corresponds to the distance
s between the outward protruding end 63 of the nose-shaped members 53 and the connecting
groove 54 formed therein.
[0066] The helical progression of the connecting lip 55 forms together with the connecting
grooves 54 a screw thread-like connection such that the force necessary to slide the
branch pipe 22 over the sealing ring 52, which force can be relatively great because
a highly fluid-tight seal can be envisaged, is generated from the screwing movement
during connection of the branch pipe 22 to a coupling piece. The branch pipe 22 is
thus pulled over the sealing ring 52 by the relatively light force necessary for the
screwing movement.
[0067] The positioning and pitch distance s of the single helical revolving connecting lip
55 and the corresponding distance s between the end 63 of the nose-shaped members
53 and their connecting grooves 54 facilitate a self-positioning screw coupling 42.
That is, a branch pipe 22 to be connected can be placed initially with its revolving
connecting lip 55 against the outer ends 63 of the nose-shaped members 53, wherein
by subsequently rotating or screwing the branch pipe 22 to the right the revolving
connecting lip 55 engages automatically in the connecting grooves 54, and by being
rotated the branch pipe 22 can be screwed firmly onto the flange 43 in a second position
of the branch pipe 22. By rotating an attached branch pipe 22 to the left back from
the second position to the first position it can be uncoupled again and removed.
[0068] In the shown embodiment the revolving connecting lip 55 has close to the second end
62 a part 56 which takes a resilient form over a distance such that at the position
of this resilient part 56 the pitch distance of the revolving connecting lip differs
from the pitch distance s between the first and second ends 61, 62 of the revolving
connecting lip 55. This differing distance may be greater or smaller than the distance
s.
[0069] During connection to the coupling piece, after screwing or rotating of the branch
pipe 22 beyond a connecting groove 54 of a nose-shaped member 53, this resilient part
56 forms a discernible indication that the branch pipe 22 has been screwed a sufficient
distance over the flange 43, and also forms a barrier, in the form of a safety catch,
against loosening of the branch pipe 22 due to vibrations or the like.
[0070] Instead of a part 56 which is resiliently divergent in axial direction of the branch
pipe 22 or the cover 44, this part can with the same effect take a resiliently divergent
form in radial direction of the branch pipe 22 or the cover 44.
[0071] The cover 44 has substantially the same construction as the branch pipe 22, is only
shorter and wherein the other end 58 of the branch pipe 22 is closed, so that the
branch pipe forms a closing cover 44 for closing the at least one connecting opening
40, 41 of the coupling piece to the outside. Formed for mounting purposes in the closed
end 58 is a cavity 59 with dimensions for receiving herein for instance a box spanner
of standardized dimensions for the purpose of loosening and/or tightening the cover
44 on a connecting opening 40, 41 of the coupling piece 30 from a shaft opening.
[0072] In an embodiment of the coupling piece according to the invention the fluid collection
channel 45 is formed as double-sided collection channel, with an outer end which is
open to both the inlet end 34 and the outlet end 35 of the coupling piece 30 for the
purpose of collecting from the inlet end 34 as well as from the outlet end 35 fluid
moving internally during use along the peripheral wall of the coupling piece 30.
[0073] The pipe segments 25, 26, 27 and coupling pieces 28, 29, 30 are connected movably
to each other in mutually gas and liquid-tight manner, for instance by means of a
per se known sealing ring 60 arranged along the inner periphery of a coupling piece
28, 29, 30 at the ends thereof and/or a sealing ring arranged along the outer periphery
of a pipe segment 25, 26, 27 or another type of sealing means known in practice for
this purpose.
[0074] Provided in an embodiment of the invention is an assembly of a respective coupling
piece 29, 30 and a pipe segment 25, 26 fixedly connected thereto. The pipe segment
25, 26 is then preferably connected fixedly to a respective coupling piece 29, 30
at the outlet end 35. Such a connection can for instance be performed by means of
self-tapping screws, but preferably by means of a thermal weld connection.
[0075] A coupling piece, such as the coupling piece 28 in figure 1, can also take a closed
form at an outer end, for instance by a closed bottom being formed in the coupling
piece 28 close to the outlet end 35 thereof.
[0076] It will be appreciated that the above described screw coupling, in particular the
self-positioning embodiment of the screw coupling, can with the same advantages be
embodied on coupling pieces without fluid collection channel.
[0077] In a practical embodiment use is for instance made of pipe segments with fixed lengths
in the range of 100-200 cm, preferably with a length of about 160 cm, for use in buildings
with storey heights of for instance 270-300 cm and with pipe segment diameters in
the range of 80 to 250 mm, preferably with diameters of 100, 130, 160 and 200 mm.
The coupling pieces can have a length here in the range of 40-60 cm, preferably about
50 cm. The diameter of a coupling piece at a respective end 34, 35 is of course adapted
here to the diameter of a pipe segment to be received therein. The branch pipe parts
have for instance a diameter in the range of 30-80 mm, preferably a diameter of 32
mm or 75 mm, adapted to standard connecting diameters for combustion devices.
[0078] The coupling pieces, pipe segments and branch pipes can be manufactured from, among
other materials, polypropylene, PP, polybutylene terephthalate, PBT, or polyvinylidene
fluoride, PVDF, with wall thicknesses of for instance 2-3 mm.
1. A tubular coupling piece (30), particularly for use in a pipe system (15) of a ventilation
or flue gas discharge channel (14), which coupling piece (30) has an inlet end (34)
and an outlet end (36) for connection to a pipe segment (26, 27) of the pipe system
(15) and wherein the coupling piece (30) is provided in its peripheral wall (36) between
the inlet end (34) and the outlet end (35) with at least one connecting opening (40,
41) for connection of a branch pipe (22) thereto, wherein the coupling piece (30)
is further provided with a stop for a pipe segment (26, 27) extending internally over
a distance in radial direction around the peripheral wall (36), which stop is configured
as fluid collection channel (45) for collecting fluid moving during use along the
peripheral wall (36) in the coupling piece (30), and wherein the fluid collection
channel (45) connects to the at least one connecting opening (40, 41), characterized in that the fluid collection channel (45) debouches into the at least one connecting opening
(40, 41) and the part (49) of the fluid collection channel (45) debouching into the
at least one connecting opening (40, 41) is provided with a fluid throughflow channel
(51) connecting internally to the peripheral wall (36) of the coupling piece (30)
for the purpose of draining through the coupling piece (30) fluid collected by the
fluid collection channel (45).
2. The coupling piece (30) according to claim 1, wherein the fluid collection channel
(45) is arranged, as seen in the direction from the inlet end (34) to the outlet end
(35) of the coupling piece (30), at the bottom of the at least one connecting opening
(40, 41) and connects thereto.
3. The coupling piece (30) according to one or more of the preceding claims, wherein
the fluid throughflow channel (51) is provided in the direction toward the peripheral
wall (36) of the coupling piece (30) with a fluid flow resistance.
4. The coupling piece (30) according to claim 3, wherein the fluid flow resistance is
formed by the fluid throughflow channel (51) rising (β) from the part (49) of the
fluid collection channel (45) debouching into the at least one connecting opening
(40, 41) to the peripheral wall (36) of the coupling piece (30), particularly wherein
the fluid throughflow channel (50) rises with a uniform inclination.
5. The coupling piece (30) according to one or more of the preceding claims, wherein
the at least one connecting opening (40, 41) is provided with a tubular flange (43)
protruding outward over a distance transversely of the peripheral wall (36) of the
coupling piece (30) for connection of the branch pipe (22) and wherein the fluid collection
channel (45) is formed over a distance along the flange (43) transversely of the at
least one connecting opening (40, 41).
6. The coupling piece (30) according to claim 5, wherein the flange (43) is formed inclining
(α) in the direction of the outlet end (35) of the coupling piece (30).
7. The coupling piece (30) according to claim 5 or 6, wherein the flange (43) is provided
on its outer periphery with at least one sealing ring (52) so that the at least one
sealing ring (52) engages fluid-tightly on the inner periphery of a branch pipe (22)
to be arranged over the flange (43).
8. The coupling piece (30) according to claim 5, 6 or 7, wherein the flange (43) is provided
with attaching members for attaching a branch pipe (22) releasably to the coupling
piece (30), particularly wherein the attaching members are embodied as screw coupling
(42).
9. The coupling piece (30) according to claim 8, wherein the attaching members comprise
at least a first and second nose-shaped member (53) protruding outward from the peripheral
wall (36) of the coupling piece (30), which nose-shaped members (53) are disposed
opposite each other at a distance from the flange (43) adjacently thereof, with a
connecting groove (54) facing toward the flange (43) for receiving therein a radially
outward protruding connecting lip (55) of a branch pipe (22) to be arranged over the
flange (43).
10. A branch pipe (22) for use with a coupling piece (30) according to claim 9, wherein
an end of the branch pipe (22) is formed for receiving the flange (43) of the coupling
piece (30) therein, and is provided with connecting lip (55) protruding outward in
radial direction, wherein the radially outward protruding connecting lip (55) is a
single helical revolving connecting lip (55) with a pitch distance (s) such that,
when the revolving connecting lip (55) is placed against the nose-shaped members (53)
and in this position the branch pipe (22) is then rotated, the revolving connecting
lip (55) engages in the connecting grooves (54) of the nose-shaped members (53).
11. The branch pipe (22) according to claim 10, wherein the revolving connecting lip (55)
takes a resilient form over a distance in axial direction of the branch pipe (22)
such that at the position of this resilient part (56) the pitch distance (s) of the
revolving connecting lip (55) differs.
12. The branch pipe (22) according to claim 10, wherein the revolving connecting lip (55)
takes a resilient form over a distance in radial direction of the branch pipe (22)
such that at the position of this resilient part the revolving connecting lip (55)
protrudes further outward in radial direction than the remaining part of the revolving
connecting lip (55).
13. The branch pipe (22) according to claim 11 or 13, wherein another end (58) of the
branch pipe (22) is closed such that the branch pipe forms a closing cover (44) for
closing the at least one connecting opening (40, 41) of the coupling piece (30) to
the outside.
14. The branch pipe (22) according to claim 11 or 12, wherein the internal diameter of
the part of the branch pipe (22) not engaging on the flange (43) is smaller than the
internal diameter of the flange (43).
15. An assembly of a coupling piece (30) according to one or more of the claims 1 to 9
and a pipe segment (26; 27) connected fixedly to the coupling piece (30), particularly
wherein the pipe segment (26; 27) and the coupling piece (30) are welded together.