Note: Descriptions are shown in the official language in which they were submitted.
8 3
BA~KGROUND OF THE INyl ~QN
The present invention relates to a conduit system comprising a plurality of large
diamemeter conduit elements wherein adjacent conduit elements may be connected
together by a coupling means in flexible yet iluid tight fashion. The coupling means may
S provide a fluid-tight joint despite variations of temperature to which the conduit
elements may be subjected. The coupling means may, for example, be conveniently used
for joining conduit elements used for feeding water to the turbines of hydro-electric
plants.
10 In industrial applications where large diameter condwt systems are involved, (such as for
the delivery and/or removal of water with respect to hydro-electric power plants), the
known practice for connecting and sealing pipe or conduit element ends to each other
has been to weld the elements together. The welding technique for joining adjacent ends
of large diarneter conduit elements has a number of drawbacks. Welding is a labour
15 intensive process requiring the attention of a skilled artisan and is thus inherently
relatively expensive to carry out. A large diamenter conduit system for a hydroelectric
installation is norrnally assembled in the ~leld, where welding may not be an easy task;
welding may, for example, pose a fire hazard during installation. Conduit elements
which are cormected together by joints which consist solely of a "weld", cannot be easily
20 dimantled for replacement and/or repair. Additionally, welded joints are more or less
rigid such that relatively complicated means (e.g. a plurality of expansion joints) must be
provided to allow for stress relief in the conduit system due to expansion/contraction of
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the conduit material in response to temperature changes, due to shifting of the conduit
support, etc...
Accordingly, it would be advantageous to have a coupling means whereby large diarneter
5 conduit elements may be connected or interlocked in a simple, economical manner,
which interlocking may be carried out by relatively unskilled workmen with relatively
simple tools.
It would further be advantageous to have coupling means which may provide a pipe
10 coupling or joint which will provide a flexible yet fluid-tight seal between two adjacent
ends of pipe or conduit elements. It would, thus, in particular, be advantageous to have
a conduit system comprising large diameter conduit elements wherein provision is made
for expansion and contraction of the pipe materials while maintaining a fluid tight seal
between coupled conduit elements.
It would be particulary advantageous to have a large diameter conduit s3rstem of the
above sort for directing water to and/or from turbine(s) of a hydroelectric generating
plant.
20 SUMMARY OF TE~E rNVEN'IlON
As mentioned above, the present invention relates to a coupling means suitable
for joining conduit elements for a conduit system which may be used for feedi~g water to
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turbines in hydro-electric plants; such systems may be very long (e.g. many kilometeres in
length). The coupling means is particulary suitable for joining length of conduits or
pipes which are subject to significant temperature variations.
S More particularly in accordance with an aspect, the present invention relates to a
coupling means for connecting together adjacent large diameter conduit elements,characterized in that
said coupling means comprises
t vo peripheral flanges, each peripheral flange being fixed to a respective conduit
element and extending radially therefrom,
and
ring clamp means,
each flange having a first side member, a second side member axially remote from the
end of the conduit section relative to the first side member and a peripheral ring
member disposed between the first and second side members,
the ring clamp means comprising
a plurality of clamp elements which together surround the said flanges, and
each said clamp element having a groove for receiving said flanges, said groove
being defined by a base member disposed between opposed side wall memberst
said groove and said flanges being configured to co-operate such that when the
clamp element is in an operative positiont the groove is sized larger than the
combined size of the flanges received in the groove so as to provide the ends of
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the connected conduit elements with a predeterrnined degree of longitudinal
movement,
and
wherein the coupling means includes
sealing means for disposition between the peripheral ring members and the base
members,
and
means for connecting the clamp elements together about the flanges in an
operative position such that
the sealing means is sandwiched between said peripheral ring members and
said base members for fluid tight sealing of said coupling means
and
the ends of the conduit elements have a predetermined degree of
longitudinal freedom of movement.
Thus, for example:
A coupling means, in accordance with the present invention may comprise annular
rings or flanges fixed on the periphery of each of the adjacent ends of adjacentconduit elements to be jo~ned together, the annular rings having upwardly and
inwardly extending side walls. A gasket formed of a resilient material may be
positioned around the periphery of said rings (e.g. in a bridging relation with
same), the annular gasket being positioned in a substantially co-axial alignment
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with the longitudinal axis of the condiuits. The coupling means may also comprise
ring clamp means having at least two clamp elements positionable around the
annular rings. The clamp elements are provided with a flange receiving channel
or groove; the groove may have a complimentary shape with respect $o the side
walls of the annular rings to matingly engaging same so that the ends of the
conduits may be drawn toward one another when the clamp elements are secured
together. The gasket may be of an annular type (i.e. of single element
construction) or may comprise a plurality of gasket elements; if the gasket
comprises a plurality of elements these elements may if desired be associated with
a respective clamp element (e.g. fixed thereto). With the clamp elements securedabout the flanges the gasket or sealing member may be radially compressed
betweeen the flanges and the clamp means. In a particular embodiment, the
annular rings may have a trapezoidal-like shape when viewed in cross section.
In accordance with a particular aspect, the present invention provides a water conduit
system, for a hydroelectric generating plant, comprising
a plurality of large diameter conduit elements wherein adjacent conduit elementsare connected together by a coupling means,
characterized in that
said coupling means comprises
two peripheral flanges, each peripheral flange being fixed to a respective conduit
element and extending radially therefrom,
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and
ring clamp means,
each flange having a first side member, a second side member axially remote from the
end of the conduit section relative to the first side member and a peripheral ring
S member disposed between the first and second side members,
the ring clamp means comprising
a plurality of clamp elements which together surround the said flanges, and
each said clamp element having a groove for receiving said flanges, said groove
being defined by a base member disposed between opposed side wall members,
said groove and said flanges being configured to co-operate such that when the
clamp element is in an operative position, the groove is sized larger than the
combined size of the flanges received in the groove so as to provide the ends of
the connected conduit elements with a predetermined degree of longitudinal
movement,
and
wherein the coupling means includes
sealing means disposed between the peripheral ring members and the base
members,
and
the clamp elements are connected together about the flanges in an operative
position such that
the sealing means is sandwiched between said peripheral ring members and
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said base members for fluid tight sealing of said coupling means
and
the ends of the conduit elements have a predetermined degree of
longitudinal freedom of movement.
In accordance with the present invention, it shall be understood the the expression "a
second side member axially remote from the end of the conduit element relative to the
first side member" characterizes the second side member as being farther away from the
repective end of the conduit element to be joined than the related first side member of
10 the same flange.
In accordance with the present invention, the opposed side wall members of the groove
of a clamp element may each have flat wall surfaces, the wall surfaces sloping away from
each other and each flange may have a second side member having a flat surface of
15 complimentary slope to that of a respective side wall member for sliding abutting
engagement therewith for urging the ends of the conduit elements towards each other
when a clarnp element passes from a non-operative position to an operative position.
The groove of a clamp element may have any desired shape or configuration keeping in
20 mind the function thereof, i.e. to limit movement of the conduit elements in co-operation
with the llanges and to (sealingly) sandwich the sealing means between it and the
flanges.
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In accordance with the present invention, the characterization of ~he groove and flanges
received therein as being sized such as to provide "a predetermined degree of
longitudinal freedom of movement" shall be understood as characterizing the coupling
means as allowing for a certain predeterrnined amount of longitudinally oriented
5 movement between the pipe ends, i.e. the coupling means provides for a certain arnount
of play between the condu;t ends (e.g. in the form of a small space between the conduit
element ends). The degree of movement allowed by any coupling means (e.g. the size of
gap between the conduit element ends) will depend on the system characteristics and the
desires of the skilled artisan. The degree of movement should not for example be such
10 as to break the (longitudinal) sealing effect of the sandwiched sealing means.
In accordance with the present invention, the opposed side wall members of the clamp
elements may, when the clamp elements are in an operative position, touch or abut
respective conduit elements. In such case, however, a radial deformation of ~he condiut
15 elements may be transfered to the side wall members of the clamp elements causing the
base members to radially separate from the peripheral ring members such that the fluid
tight seal may be broken and result in a leak. This may be dealt with by providing
sealing means of appropriate (over) thickness and appropriate resiliency and compressing
the sealing means (in the operative position) to a degree whereby a fluid tight seal may
20 be rnaintained over a predetermined range of displacement of the base mernber relative
to the peripheral ring members due to (radial) deformation of the clamp means.
Alternatively (or in addition to the above technique), in order to inhibit such possible
deformation of the clamp elements, the opposed side wall members thereof may be sized
such that, when the claInp elements are in an operative position, the opposed side wall
membe:rs of the clamp elements are spaced apart from respective conduit elements a
predetermined distance; the distance, for example, depending, inter alia, upon the
S estimated or anticipated degree of conduit element deformation in light of anticipated
environmental conditions, the materials of construction of the conduit elements, etc...
In accordance with the present invention, the clamp elements may be connected together
by any suitable or desired connection means including welding. If a weld is desired, the
10 ends of the clamp elements may be provided with connection pads or webs (as
hereinafter described) but wherein only the pads are welded together to cormect the
clamp elements in an operative position, the clamp elements being removable in such
case by cuting off the pads. However, the connection means is preferably some sort of
releasable connection means. A releasable connection means, may for example, include
15 nuts and bolts; any other known type of releasable means may of course be used.
In accordance with the present invention, each flange of the coupling means may be
disposed such that the first member of the flange is adjacent to the end of a respective
conduit element.
In accordance with the present invention, a large diameter conduit element may have an
inner diameter of 90 cm or more, e.g. an inner diameter of from about 90 cm to about
500 cml or more. Other dimensions and other physical characteristics of the va~ious
elements and members may also vary in relation to such factors as (water) pressure
(which may range for example from 50 to 300 psi), conduit element length, materials of
constmction, etc.. The coupling means will of course be sized and so constructed as to
take such factors into account.
In accordance with the present invention, the coupling means may, if desired, include
adjustment means for adjusting the predetermined degree of movement; the adjustment
means may take any form. The adjustment means may, for exarnple, comprise an
adjustment screw having an abutment end extending through a side wall member of a
clamp element groove for abutting contact with a respective side member of the flange.
A plurality of such screws may for exarnple be disposed symetrically about the coupling
means.
Various csupling clamps mechanisms, techniques, sealing means, etc, are known which
may be incorporated into a system or coupling means of the present invention. The ring
clamp means may have any desired number of clamp elements. The ring clamp
elements may, for example, comprise two identical ring halfs which have inner sides with
surfaces for abutting contact with complementary shaped surfaces on the second side
members of the flanges; see for example U.S. patent no 2,720,079 and no. 3,398,978 (the
entire contents of both of which are herein incorported by reference) for an example
configuration for the grooves and flanges keeping in mind the requirement of the present
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invention that the requisite play be present between the conduit ends. Insofar as the
radially compressable sealing means is concerned these may take on a ~at cross sectional
structure, a C-type cross-sectional structure, an E-type cross sectional structure, etc... See
for example U.S. patent nos 3,351,352, 3,851,901 and 4,561,678 {the entire contents of all
5 of which are herein incorporated by reference); although these latter references show a
single sealing means which bridges the gap between the ilanges the annular sealing
means in the context of the present invention may if desired comprise two or more
spaced apart gaskets each gasket individually sandwiched between a respective flange
peripheral ring member and the base of the groove of the clamp elements. Exarnple
10 releasable type bolt and nut connections for joining the clamp elements together are for
exarnple shown in U.S. patent nos. 2,720,079 and 3,398,987; U.S. patent no. 4,561,678
shows an alternate releasable connection mechanism. U.S. patent no. 2,878,041 (the
entire contents of which are herein incorporated by reference) illustrates a possible screw
adjustement means which may be adapted for use in the context of the present invention
15 for adjusting the play between the conduit element ends.
DESCRIPTION OF DRAWINGS
One exemplary embodiment of the invention is described in more detail below
with reference to the drawings in which:
Figure 1 is a perspective view of portions of conduit elements connected
together by an example coupling means in accordance with the
present invention;
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Figure 2A is a cross section of the coupling means shown in figure 1;
igure 2B is a cross section view of a second example embodiment of
acoupling means in accordance with the present invention,
Figure 2C is a cross section view of a second example embodiment of flange;
Figure 3 is a sectional view taken through the pipe coupling system in accord
with the invention along 3-3 of figure 1,
Figure 4 is a perspective view of portions of conduit elements shown in figure
1 with the clamp means removed;
Figure SA is an elevational view of a further example of a clamp means inaccordance with the prewsent invention which includes four equal
clamp elements releasably together by bolt and nut combinations
with the conduit elements removed;
Figure SB is a sectional view of an example cross-section of a clamp element
taken through the clarnp means shown in figure 5A along 5-5;
Figure 5C is a sectional view of an alternate example of a cross-section of a
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clarnp element taken through the clarnp means along 5-5 of figure
SA;
~Figure 5D is a partial side view of the daInp means shown in figure SA
showing webs of the clamp connection means with holes
therethrough for the engagement of bot and nut combinations;
Figure 6 is a sectional view along 6-6 taken through the clamp element of
figure 5D;
Figure 7 is a cross sectional of another exarnple of a coupling means view
showing screw adjustment means;
Figure 8 is an e%ploded cross sectiona view showing the steps of the process
of engaging a coupling system in accord to the present invention in
an operative position;
Referring now to the drawings and more particularly to figures 1 to 4, there is
shown a coupling means 5 in accordance with the present invention coupling together the
adjacent ends of two large diameter conduit elements designated by the referencenumeral ?. Each of the conduit elements 7 have generally the same tubular
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configuration of circular cross-section; however it will be appreciated that the conduit
elements in accordance with the present invention can be of difEerent configuration, the
coupling means being configured or shaped accordingly.
S The coupling means 5 as shown in figure 1 has two identical ring clamp elements 8
provided with webs which are bolted together by nut/bolt combinations 9 (the second
web-nut/bolt combination is hidden from view on the other side of the conduit
elements). The clamp elements encircle the ends of the conduit elements 8.
10 Turning to figure SB each clamp element 8 is provided with a groove 10 defined by
opposed sloping side wall surfaces 11 (the side wall members) and a base surface 12 (the
base member). The example clamp element embodiment as shown in figures 2A, SB,
etc. is made from three separate pieces or sections 13, 14 and 15, sections 14 and 15
being welded to section 13.
In an alternate embodiement of the clamp elements as seen in figures 5C, 7 and
8, (the same reference numerals being used to designate the same elements) sections 13,
14 and 15 are unitary (e.g. the clamp element is a molded structure).
20 Turning to figures 2A, 3 and 4 the coupling means 5 comprises two annular rings or
flanges 16 fil~ed on the periphery of each of the conduit or pipe elements 7. The annular
rings 16 can be welded to the conduit elements 7 or similarly affixed to same or can be
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made integral with same; the annular rings may be hollow or solid as desired. As may,
for exa~mple, be seen from figure 4, the flanges 16 extend radially for the conduit
elements 7.
5 The annular rings 16 each have a first side surface 17 (the first side member), a second
side surface 18 (the second side member) and a peripheral ring surface 19 (the
peripheral ring member); as shown the annular rings 16 are solid but may be hollow if
desired. As may be seen, the first side surfaces 17 are adjacent to the ends of the
respective conduit elements 7 whereas the second side surfaces 18 are on the side of the
10 flanges 16 remote from the conduit element ends relative to the first side surfaces 17.
The second side surfaces 18 of each of the annular rings 16 slope upwardly, and inwardly
converge (towards each other) so as to provide when viewed in cross-section as a whole,
a generally trapezoidal shape or configuration as shown in figure 2A. The second side
surfaces 18 of the annular rings 16 may matingly engage with the complimentary sloped
15 surfaces of the side wall members of the groove of the clamp elements as it will be
appreciated hereinafter.
Turning to figure 2A this figure shows the clamp element 8 in an operative position
wherein the two flanges 16 are received in the groove 10 of the clamp element 8. As
20 may be seen the groove 10 and the flanges 16 are sized to cooperate such that a degree
of play is provided between the two conduit elements; in the figure shown the play is
highlighted (with the surfaces 18 and 11 in abuting contact) by a space or gap between
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16
the first side surfaces 17, the gap being designated by the reference numeral 20.
~s may be seen from figure 2A, with the clamp element 8 in the operative positiorl, the
conduit elements are spaced apart from the sections 14 and 15 by gaps 14' and 15'
S respectively. These gaps as mentioned above will inhibit displacement of the clamp
element 8 due to radial deformation of the conduit elements, i.e. there is a degree of
play within which the conduit element 7 may move without abutting the opposed side
wall members of the clamp element 8.
10 The coupling means 5 also includes a resilient sealing gasket 21 disposed as may be seen
in figure 2A such that in the operative position it is sandwiched in fluid tight fashion
between the base surface 12 and the ring surfaces 19 of the flanges 16. Gasket 21, when
properly engaged by the base and ring surfaces (i.e. compressed), provides a fluid tight
seal at the joint between the conduit elements.
The gasket 21 may be formed of any material specific to this application and ~pically, it
is formed from a relatively hard rubber-like material. In the embodiment shown in figure
2A, the gasket is generally rectangular in cross section.
An alternate embodiment of a coupling means in an operative position is shown
in figure 2B. In figure 2B, the resilient sealing gasket 22 has a ~-shape ~pe cross
section. The gasket 22 has a top portion 23 (abutting the base surface 24), side portions
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17
25 and 26, and foot portions 27 and 28. The gasket 22 is provided with an annular
cavity 29 being generally of T-shape cross section. The sides 25 and 26 have a surface of
slope complimentary to that of the respective abutting surface of the side walls of the
coupling element 30. The distance between the feet 27 and 28 is about the gap 31. Any
S fluid in the conduit elements 32 which may find its way up through the gap 31 and into
the gasket cavity 29 will not, due to the compression applied to the gasket in the
operative position, be able to leak out past the gasket. However, if desired, a further
secondary (annular) gasket 33 may be provided between the first side members 33a of
the flanges.
Turning back to figure 2A,as mentioned above, the predetermined play provided to the
conduit elements by the flanges 16 and the clamp element 8 is chosen such that the
longitudinal displacement of the conduit elements 7 due, for example, to temperature
variations, will not result in a separation of the sandwiched gasket 21 from sealing
abutment with the ring surfaces 19 of the flanges 16 and the base surface 12 of the
clamp element 8.
The above described embodiments of the coupling means (i.e the sloping engagement of
the second side members of the flanges and the side wall members of the clamp means)
20 is particularly useful for coupling pipes of large diameter since perfect aligmnent of the
adjacent pipe sections is not necessary before securing same together.
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As shown in figure 2C, the sloped surface 34 of the second side member of an
annular flange need not extend over the entire side surface of the flange.
An alternate form for the ring clamp means is shown in figures SA, 5D and 6.
The clamp means is shown as having four identical clamp elements 35, 36, 37 and 38;
these clamp elements need not of course be identical but are preferably so for ease of
manufacture. Bolting pads or webs 39 are provided at the end of each of the clamp
elements. These bolting pads 39 are used to secure each and every clamp element to
one another by bolt(s) (not shown) in threaded engagement with nut(s) (not shown), the
body of the bolt passing through aligned holes 40 in adjacent webs 39. Alternatively, as
mentioned above, the pads 39 may be welded together in the region of the holes 40; in
order to remove the clamp elements from the operative position, however, the pads can
be cut at some point between the weld and the body of the clamp elements so as to free
the pads from each other. A releasable mechanism is, however, preferable to such a
weld, i.e. for simplified installation and removal.
Each of the clamp sections may if desired be provided with external ridges (not shown)
for augmneting the strength thereof so as to withstand high(er) pressure(s). It is to be
understood that such ridges can be welded directly onto the clamp elements.
Figure 8 illustrates in an exploded view, the attachment of the ring clamp meansto the flanges. Starting at the top of figure 8 the ends of adjacent conduit elements are
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disposed near to one another, in at least approximate alignment with one anothers'
respective longitudinal axes and spaced apart to define a gap therebetween. Each of
the cla~mp elements may if desired have fixed to the base surface thereof a portion of the
sealing gasket; the section of gasket fixed thereto may extend beyond the length of the
S base surface a small amount such that when the clamp elements are in the operative
position the ends of adjacent gasket sections are forced into abutting sealing contact.
During the alignment process, however, if the clamp elements do not have a gasket
section fixed to the base surface, a single annular sealing gasket 21 may be placed about
the adjacent ring surfaces of the flanges i.e. the gasket being sufficiently wide so as to
cover the gap 31. The clamp elements 8 are then clamped over and about the junction
of the flanges by means of nuts and bolts (not shown). When the sides 25 and 26 of the
clamp elements abut respective second sides 18 of each of the flanges 16, the generally
inwardly radially directed force created by the connecting the clamp elements together
(more particula~ly by the tightening of the bolts and nuts) is transferred into a
longitudinally directed force forcing the flanges towards each other until a desired
predetermined spacing of the ends of the conduit elements is achieved. During the
tightening, gasket 21 will sandwiched into sealing engagement with the flanges and clamp
means. The spacing or gap will ensure the possibility of relative movement of one pipe
with respect to the other.
As shown more particularly in figure 7 screw adjustment means 41 in the form of
a bolt can be used to force the end of one conduit element toward the other as a simply
mechanism for adjusting the degree of play (i.e. gap size) available between the ends of
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conduit elements; any number of such screw adjustment means may be provided. A
pluralilty of such adjustment means may, for example, be disposed symetrically about the
clamp means.
It will be understood further that variations or modifications can be undertalcen in
5 the module illustrated and described by those skilled in the art without departing from
the spirit and scope of the invention as defined by the appended claims. For example,
the dimensions mentioned above are given for the sake of clarity only and should not be
construed as limiting the invention in any way. The clarnp elements, the annular rings,
the sealing means can have a different shapes than those illustrated in the enclosed
10 drawings. Thus, the clamp elements may comprise radially extending lugs provided with
openings to receive securing means in the form of bolts and nuts.
In the foregoing description certain terms have been used for brevity, clearness
and understanding, but no necessary limitations are to be implied therefrom beyond the
requirements of the prior art, because such words are used for descriptive purposes
15 herein and are intended to be broadly construed.
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