Note: Descriptions are shown in the official language in which they were submitted.
CA 02697763 2016-08-29
PIPE JOINT RESTRAINT
CROSS-REFERENCE TO RELATED APPLICATIONS
Application claims priority to Provisional Patent Application No. 61/163,398
filed March 25, 2009.
BACKGROUND
This invention relates to a method and device that helps maintain the
integrity
of a pipe system when subjected to abnormal internal pressures. It is
especially useful
in drain pipe systems made of cast iron.
In a typical building drain piping system, sections of cast iron drain or DWV
(drain, waste and vent) pipe and their fittings are assembled by butting the
ends of the
pipe sections together and bridging the joints with water-tight rubber or
rubber/metal
couplings. These abutting pipes and fittings are secured together and sealed
with
metal band screw clamps tightened to about 60 in-lb of torque to compress the
tubular
sleeves. This is commonly called a "no-hub" cast iron system.
Building drain or DWV piping is considered a low-pressure application
typically operating at about 5psi or less when in service, Such piping systems
are not
usually subject to the rigorous engineering of a pressurized pipe system.
However, under "high" pressures, e.g., above 15-20 psi, such as might occur
within the piping system when drains become blocked in a multi-story building
or
under system pressure testing, these joints and fittings have a tendency to
move and
sometimes separate, with resulting leakage and property damage. The thrust
forces
involved in causing the separation can vary from a few hundred pounds to
several
thousand pounds, depending on the size of the pipe and number of floors behind
the
drain back-up.
At least in part because gravity (the weight of the pipe) does not effectively
counter the separation forces where the pipe is running horizontally, such
joint
failures tend to occur at or near the point where the drain piping changes
direction
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from vertical to horizontal, particularly as commonly occurs at the base of a
multi-
story vertical "stack" of pipe, such as at the building ground floor. Where
the joints at
such transitions are able to withstand the pressure and maintain integrity,
however, the
next and subsequent joints in the horizontal piping at which changes in
direction
occur may also be subject to the same type of failure.
There is no standard solution to this, and not every building contractor takes
the pains to address it. A common method of dealing with the potential problem
is to
fabricate some kind of "splint" system on-site to reinforce major vertical-to-
horizontal
transitions in the piping, using bulky and often expensive combinations of
threaded
rod, fasteners, scrap or fabricated metal or heavy pipe "riser clamps" which
are large,
usually heavy-gage metal clamps which look like bear traps and which are
commonly
used to support the weight of vertical pipe runs by resting on the decks of
consecutive
building floors. There is thus a need for way to restrain movement in the
joints
adjacent to a bend in the drain/DVW piping, and to reduce the solution down to
a
simple, standardized, easily transported and installed device, which can be
capable of
working with a range of pipe sizes, pipe types, and pipe pressures.
BRIEF SUMMARY
A restraint strap has each end provided with a pipe connector. One pipe
connector encircles and clamps against an underlying adjacent pipe section.
The
other pipe connector encircles and clamps against a different adjacent pipe
section or
to the pipe fitting. The strap length may be adjusted to tighten the straps
and urge the
clamped pipe section(s) toward the pipe fitting. The straps restrain the
adjacent pipe
sections from moving away from the pipe fitting during high pressure or high
flow
conditions. The straps restrain the adjacent pipe sections from splaying
during high
pressure or high flow conditions. The pipe connectors may encircle the tubular
sealing sleeves that sealingly join the adjacent pipe sections to the pipe
fitting.
Preferably, two straps, each with pipe connectors are used to connect the
adjacent
pipe sections. The straps are preferably in the same plane to provide
symmetric
forces to the connected pipe sections and thus avoid tilting or canting
relative to the
connected parts. The centerline of the flow path is also in that same plane.
Depending on the shape of the pipe fitting, different strap lengths are
provided with
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the pipe connectors fastening to different adjacent pipe sections or different
parts of
the pipe fitting.
There is thus advantageously provided a pipe joint having a first flow path
with a first centerline passing through a first adjacent pipe section, a pipe
fitting and a
second adjacent pipe section. The pipe fitting separates the adjacent pipe
sections.
Each adjacent pipe section is sealingly joined to the pipe fitting by tubular
seals. The
pipe restraint on this joint includes a first strap extending between the
adjacent pipe
sections. The first strap has opposing ends with each end connected to one of
a first
and second pipe connector. The pipe connectors are on the same side of the
first
strap. Each of the first and second pipe connectors encircles and clamps to a
different
one of the first and second adjacent pipe sections. The first strap has a
length that
extends in a first plane that also contains the first centerline;
The pipe joint has a second strap with a length also extending in that first
plane. The second strap has opposing ends each connected to one of a third and
fourth pipe connector. The third pipe connector is connected diametrically
opposite
the first strap to one of the first and second adjacent sections, and the
fourth pipe
connector is connected to either the other adjacent pipe section or to the
pipe fitting.
In further variations, this pipe joint has the fourth pipe connector connected
to
the other adjacent pipe section. Preferably, but optionally, least one of the
first and
second straps further includes an adjustable length mechanism to tighten the
at least
one strap and urge the adjacent pipe section to which the adjustable length
strap is
connected toward the pipe fitting. The pipe fitting may be curved, with the
second
strap forming an outer strap extending along an outer periphery of the curved
pipe
fitting and with the fourth pipe connector connected to the other adjacent
pipe section.
The pipe joint may have a substantially straight centerline with the first and
second
straps substantially parallel along a substantial portion of the length of the
first and
second straps. The pipe fitting may be a reduction fitting having a centerline
that is
substantially straight and with the first and second straps substantially
parallel for a
portion of the length of the straps, but inclined toward each other for a
portion of the
length of the straps.
The pipe joint may have a pipe fitting with a second flow path passing through
the fitting and a third adjacent pipe section. The second flow path has a
second
centerline merging with the first centerline through a portion of the pipe
fitting. In
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this variation, the fourth pipe connector may connect to the third adjacent
pipe
section. In this variation, the pipe joint may include at least one additional
strap
having opposing ends each having one of fifth and sixth pipe connectors, with
the
fifth pipe connector fastened to the third adjacent pipe section and the sixth
pipe
connector fastened to the pipe fitting. In this variation, one of the adjacent
pipe
sections may include a blind end, with the fourth pipe connector connected
adjacent
an outlet of the pipe fitting leading to the blind end and the second strap
crossing the
blind end and the fourth pipe connector.
In further variations, the pipe joint may have each end of the pipe connectors
comprising a clamp encircling the pipe, with at least one end of each strap
having an
adjustable fastener to vary the length and tightness of the strap to which the
adjustable
fastener is connected. Advantageously, but optionally, each end of the pipe
connectors encircles one of the sleeves. Alternatively, or in addition, one or
more of
the pipe connectors may comprise a split ring clamp encircling the pipe, with
at least
one of the straps having an adjustable length fastener connecting the strap to
the
clamp in order to vary the tightness of that strap.
There is also provided a kit for maintaining the position of pipe sections
that
are joined to a pipe fitting having a first flow path with a first centerline
passing
through first and second adjacent pipe sections during use. The pipe fitting
separates
the adjacent pipe sections during use. The kit includes a first strap having
opposing
ends each of which is fastened to a first pipe connector extending from the
same side
of the first strap. Each first pipe connector is of sufficient size to
encircle a different
one of the adjacent pipe sections during use. The first strap has a length
sufficient to
extend at least between the adjacent pipe sections in a straight line during
use. The kit
also includes a second strap having opposing ends each of which is fastened to
a
second strap pipe connector that extends from the same side of the strap. Each
second
pipe connector is of sufficient size to encircle a different one of the
adjacent pipe
sections during use. The outer strap has a length sufficient to extend at
least around
an outer periphery of the pipe fitting and reach the adjacent pipe sections
during use.
Each of the first and second pipe fittings comprise adjustable diameter ring
clamps.
In further variations, the kit may include a second strap includes an
additional
second pipe connector connected to the second strap and located between the
ends of
the second strap and extending from the same side of the strap as the other
second
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pipe connectors. The additional pipe connector may be movably connected to the
second strap so it can be moved along a length of the second strap. The kit
may have
each strap provided with an adjustable length mechanism or connector to vary
the
length of the strap. The kit may include at least one tubular sealing sleeve
and clamps
5 to seal
the sleeve against one of the adjacent pipe sections or pipe fitting during
use.
The kit may further include the pipe fitting.
There is also provided a method of restraining movement of pipe sections
sealingly joined to a pipe fitting by tubular seals where the pipe fitting has
a first flow
path with a first centerline through first and second adjacent pipe sections.
The
method includes: placing a first strap between the first and second adjacent
pipe
sections, with the first strap having a length with opposing ends each
connected to one
of a first and second pipe connector, on the same side of the first strap. The
method
includes connecting the first and second pipe connectors to a different one of
the first
and second adjacent pipe sections so the first strap extends in a first plane
also
containing the first centerline. The method further includes placing a second
strap
having a length with opposing ends with each end connected to one of a third
and
fourth pipe connector so the third end is adjacent the same adjacent pipe
section as the
first pipe connector. The method also connects the third pipe connector
diametrically
opposite the first strap to the same adjacent pipe section as the first pipe
couples. The
method also connects the fourth pipe connector to either the other adjacent
pipe
section or to the pipe fitting so that the length of the second strap lies in
the first
plane. Finally, the method also connects a first end of a second strap to one
of the
first and second adjacent sections, and connecting the fourth pipe connector
to either
the other adjacent pipe section or to the pipe fitting.
The method preferably includes connecting the fourth pipe connector to the
other adjacent pipe section. Moreover, at least one of the first and second
straps may
include an adjustable length mechanism to tighten the at least one strap and
urge the
adjacent pipe section to which the adjustable length strap is connected toward
the pipe
fitting.
Additionally, the pipe fitting may be curved and the second strap may include
an outer strap extending along an outer periphery of the curved pipe fitting,
with the
fourth pipe connector connected to the other adjacent pipe section. Moreover,
the
centerline may be substantially straight with the first and second straps
substantially
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parallel along a substantial portion of the length of the first and second
straps. The
pipe fitting may comprise a reduction fitting with the centerline
substantially straight
and the first and second straps substantially parallel for a portion of the
length of the
straps, but inclined toward each other for a portion of the length of the
straps. The
pipe fitting may include a second flow path passing through the fitting and a
third
adjacent pipe section, the second flow path having a second centerline merging
with
the first centerline through a portion of the pipe fitting, in which case the
method
includes connecting the fourth pipe connector to the third adjacent pipe
section.
At least one additional strap having opposing ends each having one of fifth
and sixth pipe connectors may be provided, in which case the method includes
connecting the fifth pipe connector to the third adjacent pipe section and the
sixth pipe
connector to the pipe fitting. The method may also include providing one of
the
adjacent pipe sections as a blind end, in which case the method includes
connecting
the fourth pipe connector adjacent an outlet of the pipe fitting leading to
the blind end
and placing the second strap so it crosses the blind end and the fourth pipe
connector.
The method may include providing each of the pipe connectors as a clamp
encircling
the pipe, with at least one end of each strap having an adjustable fastener to
vary the
length and tightness of the strap to which the adjustable fastener is
connected.
The method may include providing pipe connectors with an adjustable
diameter band clamp and further include the step of adjusting the tightness of
at least
one of the straps. The pipe connectors may comprise a split ring clamp
encircling one
of the adjacent pipes, with at least one of the straps having an adjustable
length
fastener connecting the strap to the clamp in order to vary the tightness of
that strap.
Moreover, sealing sleeves may be placed over the connections between the pipe
fitting and the adjacent pipe sections, or integrated with the fitting, at
least one of the
pipe connectors being placed to encircle and compress one of the sleeves. The
method may include adjusting the tightness of the inner and outer straps to
increase
the tension in each of the straps.
In much more detail, a joint restraint is provided for a curved pipe joint
having
a curved pipe section joining two adjacent pipe sections. The pipes are joined
using
tubular rubber or elastomeric sleeves held by various clamps, such as hose
clamps, to
form fluid tight seals. Preferably, at least two sleeve-type clamps are
secured at the
junctures of the curved pipe section and each adjacent pipe section. Two pipe
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connectors also encircle each proximal end of the adjacent pipe sections and
if
desired, may also sealingly join the curved pipe section to adjacent pipe
sections. An
inner strap extends between and fastens to one of the pipe connectors on each
adjacent
pipe section forming a chord of an arc. An outer strap extends along an outer
periphery of the joined pipes and fastens to the other pipe connector on each
adjacent
pipe section. Each of the two pipe connectors attached to each strap is
located on a
different one of the adjacent pipe sections. The straps have a length
extending in a
plane through a center of the flow path of the joined pipes. The straps are on
diametrically opposing sides of the sleeves and pipes. The pipe connectors are
positioned to provide straps that are tight enough so that the inner strap
restrains or
impedes outward splaying of the curved pipe section and adjacent pipe sections
joined
thereto. The pipe connectors are positioned to provide straps that are tight
enough so
that the outer strap restrains or impedes movement of the adjacent pipe
sections
toward each other, or tilting of the adjacent pipe sections, or movement of
the
adjacent pipe sections away from the curved pipe section. Advantageously, the
clamps are hose clamps or pipe clamps.
In a further embodiment, a restrained pipe joint is provided where the pipe
joint has a flow path therethrough. The restrained pipe joint has a curved
pipe section
having opposing first and second ends. An inner curved periphery is located in
a plane
containing a center of the flow path and an outer curved periphery in the same
plane.
First and second adjacent pipe sections each have a proximal end adjacent the
curved
pipe section. First and second tubular sleeves are provided along with a
plurality of
clamps to join the adjacent pipe sections to the curved pipe section. Each
sleeve has a
proximal end adjacent the curved section and has an opposing distal end with
at least
one of the clamps sealingly connecting the proximal end of the sleeve to a
different
end of the curved pipe section. Each distal end of the sleeves is further
connected to a
proximal end of a different adjacent pipe section, with at least one of the
clamps
sealingly connecting the distal end of the sleeve to the proximal end of the
adjacent
pipe section. An inner strap is provided that has opposing ends each connected
to the
distal end of each pipe on an adjacent pipe section, preferably through a pipe
connector that encircles one of the adjacent pipe sections or possible
encircles part of
the pipe fitting to which the pipe sections are joined. The inner strap
restrains the
distal ends of the sleeves and associated adjacent pipe sections from
splaying. An
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outer strap extends around an outer periphery of the curved pipe section and
has
opposing ends each connected to the distal end of each adjacent pipe on an
outer side
of each adjacent pipe through a pipe connector. The outer strap restrains the
distal
ends of the sleeves and associated adjacent pipe sections from moving toward
each
other, and may restrain the associated adjacent pipe sections from moving away
from
the curved pipe section either alone, or in conjunction with the inner strap.
The pipe
connector to which the inner and outer straps connect preferably connects
directly to
the adjacent pipe sections by encircling those pipe sections and clamping to
them, but
the tubular sleeves could be interposed between those pipe connectors and the
pipe
sections.
Preferably, each end of the straps connects to one of the pipe connectors
adjacent to a distal end of the sleeve on that pipe section. Optionally, each
end of the
straps connects to a different one of the pipe connectors with the connectors
encircling a distal end of the sleeve to further seal against leakage. Each
end of the
outer strap is preferably connected to the pipe connectors that are closer to
the curved
pipe section.
In the above and other pipe joint and variations, the inner strap is
preferably
substantially straight and tight, and extends across a space between adjacent
pipe
sections or pipe fittings. In the above and other pipe joint and variations,
the outer
strap closely follows the contour of the pipe joint and typically abuts the
outer surface
of the pipe and sealing sleeves and associated sealing clamps. Moreover, the
inner
and outer straps connect to the pipe connectors at locations that are on
opposite sides
of the pipe sections and fittings, with the straps preferably having lengths
which lie in
a common plane, and more preferably which lie in a plane containing the flow
path
through the pipe joint. Further, the outer strap can be advantageously
fastened to an
outer periphery of the curved pipe section to ensure the strap remains in the
preferred
plane.
Further variations are provided which use T fittings and Y fittings, each
having various adjacent pipe sections or additional pipe fittings connected by
sealing
tubes and clamps. In each variation, a strap extends across the joint to
fasten the
adjacent pipe section or pipe fitting to the main fitting or to an adjacent
pipe section in
order to restrain relative movement or tilting of the joined parts. Those
straps or are
held to the respective parts by pipe connectors that preferably clamp the ends
of the
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straps to the respectively joined and restrained parts by an adjustable
tightening
mechanism. Preferably, the length of the straps can be changed to tighten the
straps
and urge the joined parts of the pipe joint toward each other. Ideally, the
straps are
symmetrically placed on diametrically opposing sides of the pipe sections and
joints
to reduce tilting or canting of the joined parts.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features and advantages of the various embodiments disclosed
herein will be better understood with respect to the following description and
drawings, in which like numbers refer to like parts throughout, and in which:
Fig 1 is a perspective view showing the inner side of a pipe joint of this
invention;
Fig. 2 is a side perspective view of the pipe joint of Fig. 1;
Fig. 3 is a back perspective view of the pipe joint of Fig. 1, showing the
outer
periphery of the joint;
Fig. 4 is a side plan view of the pipe joint of Fig. I;
Fig. 5 is a right side plan view of the pipe joint of Fig. 4;
Fig. 6 is a left side plan view of the pipe joint of Fig. 4;
Fig. 7 is a top plan view of the pipe joint of Fig. 4;
Fig. 8 is a bottom plan view of the pipe joint of Fig. 4;
Fig. 9 is an enlarged plan view taken along circular section 9-9 of Fig. 4;
Fig. 10 is a perspective view of the pipe joint of Fig. 1 with a variation in
straps;
Fig. 11 is a perspective view of the pipe joint of Fig. 10 showing the outer
periphery and outer strap;
Fig. 12 is a perspective view of the straps shown in Fig. 1 without the pipe
joint;
Fig. 13 is a perspective view of the straps shown in Fig. 2 without the pipe
joint;
Fig. 14 is a perspective view of an inner strap with an adjustable length or
adjustable force connection on each end of the strap;
Fig. 15 is a perspective view of an outer strap with an adjustable length or
adjustable force connection on each end of the strap;
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Fig. 16 is a perspective view showing the inner side of a larger diameter pipe
joint of this invention;
Fig. 17 is a perspective view of the pipe joint of Fig. 16 without the pipes
and
sealing sleeves;
5 Fig. 18 is an enlarged perspective view of a portion of Fig. 16
showing the
connection between the inner strap and pipe connectors;
Fig. 19 is a lower perspective view of a 90 degree pipe joint with inner and
outer straps;
Fig. 20 is a sectional view taken along flow path centerline 13-13 of Fig. 19
10 Fig. 19A is a perspective view of a 45 degree pipe joint showing the
inner
strap;
Fig. 20A is side view of the pipe joint of Fig. 19A;
Fig. 21 is a back side perspective view of the pipe joint of Fig. 19A, showing
the outer strap;
Fig. 22 is a perspective view of a 45 degree pipe joint with two pipe
connectors showing the inner strap;
Fig. 23 is a side plan view of the pipe joint of Fig. 22;
Fig. 24 is a back side perspective view of the pipe joint of Fig. 22 showing
the
outer strap;
Fig. 25 is a back side perspective view of a T-joint using the straps and pipe
connectors of this invention;
Fig. 26 is a side plan view of the T-joint of Fig. 25 with the opposing side
being a mirror image thereof;
Fig. 27 is a front side perspective view of the T-joint of Fig. 25;
Fig. 28 is a back side perspective view of a T-joint using the straps and pipe
connectors of this invention;
Fig. 29 is a side plan view of the T-joint of Fig. 28;
Fig. 30 is a front side perspective view of the T-joint of Fig. 28;
Fig. 31 is a front side perspective view of a reducing joint using the straps
and
pipe connectors of this invention;
Fig. 32 is a side plan view of the reducing joint of Fig. 31;
Fig. 33 is a back side perspective view of the reducing joint of Fig. 32;
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Fig. 34 is a front side perspective view of a blind end pipe joint using the
straps and pipe connectors of this invention;
Fig. 35 is a side plan view of the blind end pipe joint of Fig. 34; and
Fig. 36 is a back side perspective view of the blind end pipe joint of Fig.
34;
Fig. 37 is an upper, front perspective view of a pipe joint having a Y or wye
connector with a straight pipe section on each branch of the wye, and a
straight pipe
section on the leg or base of the wye;
Fig. 38 is a side plan view of the pipe joint of Fig. 37;
Fig. 39 is a lower, back perspective view of the pipe joint of Fig. 37;
Fig. 40 is a front perspective view of a pipe joint having a Y or wye
connector
with a straight pipe section on one branch of the wye and on the leg or base
of the
wye, and a curved pipe section joining a straight pipe section on the other
branch of
the wye,
Fig. 41 is a side plan view of the pipe joint of Fig. 40;
Fig. 42 is a lower back perspective view of the pipe joint of Fig.40
Fig. 43 is a front perspective view of a pipe joint having a Y or wye
connector
with a blind end plug on one branch of the wye, a curved pipe section joining
a
straight pipe section on the other branch of the wye, and a straight pipe
section on the
leg or base of the wye;
Fig. 44 is a side plan view of the pipe joint of Fig. 43;
Fig. 45 is a lower back perspective view of the pipe joint of Fig. 43;
DETAILED DESCRIPTION
Referring to Figs. 1-9 and 11-12, a pipe restraint 10 is shown having
elongated
inner and outer straps 12i and 12o, respectively. Pipe connector 14a, 14b are
fastened
to opposing ends of inner strap 12i, and pipe connectors 15a, 15b are fastened
at
opposing ends of the outer strap 12o. An additional pipe connector 15c can be
fastened to the outer strap 12o intermediate the ends of the strap as shown in
Fig. 1.
The pipe restraint 10 helps prevent a pipe joint from coming apart under high
fluid
flows through the pipe along flow path 13 through the pipe, or under high
internal
pressures in the pipe.
A typical pipe joint includes a curved pipe section 16, such as an elbow
section having a 45 or a 90 curve, with opposing ends 17a, 17b (Fig. 20).
The
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typical joint further has a first upstream pipe section 18a and a second
downstream
pipe section 18b on opposing ends of curved pipe section 16. Each pipe section
18a,
18b has a first upstream end 19a and a second downstream end 19b, with one of
the
ends sized to abut or be sealingly connected to the abutting or adjacent end
17a, 17b
of curved section 16. Thus, second downstream end 19b of upstream pipe section
16a
abuts first upstream end 17a of curved section 16, while the downstream pipe
section
16b has its first upstream end 19a abutting the second downstream end 17b of
the
curved pipe section 16. The pipe sections 18a, 18b are sometimes referred to
herein
as abutting pipe sections because they have one end abutting or connected to
curved
pipe section 16, but the sections 18a, 18b do not abut or connect directly
each other.
Further, while the ends are referred to as abutting ends, the ends may be
connected in
a non-abutting manner unless expressly described or defined as abutting.
The ends of pipes 16, 18 are of the same general size and shape and typically
abut against each other or are joined to maintain the ends very close to each
other.
The pipes are typically made of cast iron, but could be made of other
materials,
including, but not limited to, plastic, clay, porcelain or steel. The pipes
16, 18 are
typically circular in cross section.
Tubular sealing sleeves 20 are placed over the joints of the pipe ends. The
sleeves 20 are typically made of rubber or are made of metal with an inner
liner made
of an elastomeric or other sealing material, or of combinations of metal and
rubber.
The tubular sealing sleeves 20 extend over an adjacent end of each abutting
pipe with
clamps 22 clamped around a circumference of each such pipe to prevent fluid
from
leaking out between the sleeve 20 and the joint pipes 16, 18. Typically,
clamps 22 are
hose clamps or ring clamps that encircle and compress the sleeve 20 against
the pipe
underneath the clamp 22. At least one, but often two or more clamps 22 are
used to
clamp a sleeve to each of the pipes 16, 18 to help prevent or at least
minimize leakage
and to strengthen the connection.
Sometimes, the ends of the pipes 16, 18 may have a raised boss around the
distal ends of the pipe with the clamp 22 being located right by this raised
boss to
deform the sealing sleeve 20 inward against the outer surface of the pipe 16,
18 which
is slightly smaller in diameter than the boss and thus form a better seal as
the sleeve is
stretched or deformed over the larger boss. Alternatively, grooves may be
formed in
the ends of the joined pipes and the sealing sleeves 20 formed with mating
grooves.
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Such sleeves and pipes are found in Patent 3,851,901.
The pipe restraint 10 preferably fastens directly to pipe segments 18 to hold
the three joined pipe sections together under high pressure and/or flow
conditions, the
fastening location being adjacent or in proximity to the sleeves 20, but not
on the
sleeves 20. Less preferably, the pipe restraint 10 has part of tubular sealing
sleeves 20
interposed between the connectors 14, 15 so the pipe connectors compress the
sleeve
and assist sealing. The straps 12 thus preferably fasten to the proximal end
of each
pipe section 18a, 18b which ends abut or are fastened to the curved section 16
to urge
those pipe sections 18 toward the curved section 16 and hold them in place.
Figs. 1-5
show the pipe restraint 10 fastened to the proximal end of pipe section 18,
with the
abutting pipe ends concealed from view by the sleeve 20a, 20b. Advantageously,
the
pipe connectors 14 may directly grip the pipe segment 18.
As seen in Figs. 1-9, two different straps 12 are usually used, an inner strap
12i and an outer strap 12o, each of which preferably allows installation
independent
of the sleeve 20 and clamps 22. The curved pipe segment 16 has an inner side
with a
smaller radius of curvature and a smaller distance between distal ends of the
pipe in a
plane containing the center of the flow path 13 through the pipe 16, and an
outer side
with a larger radius of curvature and longer distance between distal ends in
that plane
which contains the center of the flow path 13 through pipe 16. An inner strap
121
extends between the inner ends of the curved pipe section 16, preferably in
the plane
extending through the center of the flow path 13 through middle of the pipe
16. The
inner strap 121 is generally straight and taut between the pipe connectors
14a, 14b.
The outer strap 12o extends around the outer surface of the curved pipe 16 and
part of
the abutting pipe sections 18a, 18b, also preferably in the plane containing
the center
of the flow path 13. The straps 121 and I2o are thus preferably substantially
in the
same plane. The opposing ends of straps 121 and 12o are fastened to the pipes
in that
same plane, and thus fasten to the pipes 18a, 18b at generally diametrically
c:posing
locations on the pipe 16, 18 and sleeves 20. The inner and outer straps 12i,
12o are
located in a plane containing a centerline of a flow path 13 that extends
through the
curved pipe segment, with the outer strap preferably being substantially
parallel to the
centerline of that flow path 13 through the pipe joint. Since the flow path 13
passes
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through curved pipe section 16 and straight pipe sections 18, the flow path
does not
have a constant curvature.
Each sleeve 20 is fastened to one end of the curved section 16 and one end of
the first adjacent or abutting section 18a or 18b. The downstream end 16b is
used for
illustration with the upstream end 16a having a similar connection. A first
and second
clamp 22a, 22b encircle and tighten sealing sleeve 20b against the downstream
end
17b of curved section 16. A single clamp 22 could be used, but two clamps 22
add
stability to the sleeve to resist movement and tilting of sleeve 20 relative
to curved
pipe section 16, and also provide a better fluid seal. A second set of clamps
22 would
normally seal the other (downstream) end of sleeve 20 against the adjoining or
abutting pipe section 18b. Preferably, adjacent to the end of the sleeves 20
are the
pipe connectors 14, 15. In less preferred variations of the pipe restraint 10,
the clamps
22 on the pipe section 18 that compress the sleeve 20 may be fastened to
straps 12i,
12o (or vice versa) to form pipe connectors 14, 15.
Advantageously, the inner strap 12i with its connector 14b is further from the
center of curved pipe section 16 downstream than the outer strap 12o and its
connector 15b. Both connectors 14b, 15b encircle and against the adjacent pipe
section. Further, the connectors 14b, 15b are preferably positioned to ensure
the inner
strap 12i is taut and in slight tension, and that the outer strap, 12o is also
taut and in
slight tension, with the straps 12i, 12o preferably exerting the same force on
their
respective pipe connectors 14, 15. In Figs. 1-3, the pipe connectors 15 of the
outer
strap fasten closer to the curved pipe 16 than do the connectors 14 of the
inner strap
12i. But the locations could be reversed with the inner strap 12i and its pipe
connectors 14 being located closer to the ends of the curved pipe 16 than are
the
connectors 15 to which the outer strap 12o is fastened.
Described slightly differently, each sleeve 20 has a proximal end adjacent to
and sealingly connected to a different end 17a, 17b (Fig. 20) of the curved
section 16.
Each sleeve 20 has a distal end opposite the proximal end, and each distal end
is
sealingly connected to a different one of the adjacent pipe sections 18. One
and
preferably two clamps 22 connect the proximal end of each sleeve 20 to an end
17a,
17b of the pipe section 16. One, and preferably two clamps 22 connect the
distal end
of each sleeve to one end on one of the adjacent pipe sections 18a, 18b. The
pipe
connectors 14, 15 may encircle and clamp to the adjacent pipe sections
adjacent the
CA 02697763 2010-03-25
sleeve 20. Less preferably, one or both clamps 22 connecting each sleeve 20 to
an
adjacent pipe section 18a or 18b may each be connected to one strap 121 or 12o
to
form pipe connector 14 or 15. Even less preferably, one clamp 22 may be
connected
to both straps 121 and 12o to form a common pipe connector (combining 14 and
15).
5 Increased
pressure in the pipe section formed by joined pipe segments 18a, 16,
18b will tend to splay the segments and open-up the curve formed by those
joined
segments. In other words, under high pressure or flow rates the distal ends
19a and
19b of segments 18a, 18b, respectively, tend to move away from each other, and
also
move away from the abutting end of curved pipe segment 16 along the flow path
13.
10 When one
or both of the abutting pipes 18a, 18b are urged away from the adjacent
end of curved pipe section 16, the inner strap 12i is placed in tension and
tries to bow
the curved section of pipes 18a, 16, 18b inward, moving the joined ends of
pipe
sections 18a, 18b toward each other. The outer strap 12o also opposes this
motion of
pipe sections 18a, 18b along flow path 13 such that the outer strap 12o is
pulled
15 against
portions of pipe sections 18a, 18b, 16 and sleeves 20a, 20b which abut or
connect to the strap 12o. The strength of the pipe segments 16, 18 themselves
are
thus used to restrain movement and to maintain joint integrity and reduce
leakage of
the joints with curved segment 16. Because the straps 12i, 12o are generally
in the
same plane and on opposing sides of the pipe segments 18, the straps do not
tilt the
pipe segments 18. Tilting of pipe segments 18a, 18b relative to curved section
16 will
cause the joint to leak and allow pressure to enlarge the leak and separate
the joined
pipes.
If pressure along flow path 13 pushes the first pipe sections 18a, 18b away
from the curved pipe 16, the straps 12i and 12b pull on opposing sides of the
sleeves
20 and pipes 18 to prevent movement along the flow path 13, and to prevent
tilting in
the plane containing the center of the flow path 13. If pressure along flow
path 13
causes the curved pipe section 16 to straighten and assume a larger radius of
curvature, that will cause the joint with first pipe sections 18 to tilt or
open in the
plane through the center of the flow path 13. The inner and outer straps 121,
12o
restrain that tilting of the pipe sections 18a, 18b. The straps 12i and 12o
thus help
restrain movement of the pipes 18 relative to the curved pipe section 16, and
provide
means for restraining motion of the pipes 18, especially for restraining
motion in the
plane through the straps 121, 12o and through the center of the flow path 13.
If the
CA 02697763 2010-03-25
16
connectors 14, 15 encircle and clamp to the pipes 18a, 18b through the sleeves
20,
then the connectors 14, 15 also help limit movement of the sleeves.
The strap 12o is thus positioned along on the greatest length of the curved
pipe
section 16, and the inner strap 12i extends along the longest chord between
opposing
ends of the curve formed by curved pipe 16 and its abutting pipes 18a, 18b.
The pipe
connectors 14, 15 are preferably adjusted to achieve and maintain this
location. Thus,
the outer strap 12o has a third pipe connector 14c which preferably fastens at
or about
the middle of the curved pipe section 16 to fasten the center of the strap 12o
to the
pipe 16 and to prevent it from slipping sideways around the pipe 16 and toward
the
inner side of that pipe. Pipe connector 14c is advantageously movably
connected, and
preferably slidably connected to strap 12o such that the connector 14c is
moved or
slid along the length of strap 12o to the most suitable position of strap 12o
relative to
the particular shape of the curved section 16. In some instances it may be
advantageous to have the connection with the adjacent pipes 18a, 18b further
from the
curved section 16 and more toward the middle of the adjacent pipe(s) 18.
The outer strap 12o thus wraps in an arc around the outer-most contour of the
pipe bend 16 and a portion of adjacent pipes 18. The outer strap 12o is
preferably
secured to the curved pipe segment 16 and to each of the two abutting pipe
segments
18 just after the sealing sleeves 18, and alternatively on part of the sleeves
by having
the pipe connectors 15 clamp onto the sleeve(s) 20. The outer strap 12o acts
as a
passive tensile restraint against axial movement in the joint and against
movement of
the pipe segments 18 along flow path 13. For lower pressure applications, use
of the
outer strap 12o by itself may be sufficient and inner strap 12i may be
omitted. As
described later, the outer strap 12o may be placed in tension to form an
active restraint
by urging the adjacent pipe sections 18 toward the curved section 16.
For applications with higher potential pressures (e.g., taller buildings or
larger
pipes), the outer strap 12o may be supplemented by the inner strap 12i which
preferably has its own two clamping or other securing means such as the
connector
14. The inner strap 12i is tensioned diagonally across the bend formed by
segments
18a, 16 and 18b to form a chord of the arch formed by those pipe sections. The
inner
strap 121 is clamped or otherwise secured to the two adjacent pipe sections
18a, 18b.
This inner strap 12i counters the tendency of the two adjacent pipe sections
18a, 18b
of the joint to splay outward and separate under higher pressures.
CA 02697763 2010-03-25
17
The inner strap 121 thus provides a tension member connected to opposing
portions of pipes abutting a curved segment of pipeline on the inside of those
abutting
pipe segments and preferably in the plane through the centerline of the flow
path
through that curved pipeline segment and immediately adjoining segments to
restrain
that curved pipeline assembly from splaying outward to spread the ends of that
assembly further apart. The outer strap 12o provides a tension member
connected to
opposing portions of the pipe segments abutting the curved segment of pipeline
and
located on the outside of those abutting pipeline segments and preferably in
the plane
through the centerline of the flow path through that curved pipeline segment
assembly
in order to restrain those abutting segments or portions thereof from moving
inward
toward each other and to provide a symmetric restraint opposite the location
of the
inner strap 12i to reduce and preferably prevent the pipes adjoining the
curved pipe
segment from tilting or canting relative to the initial flow path 13.
The inner and outer straps 12i, 12o pull the end segments 18a, 18b against the
curved section 16, placing the assembly in compression. That compression helps
prevent the end segments 18 from being pushed away from the curved section 16
by
the flow of water or by water pressure. The positioning of straps I2i, 12o
helps
maintain the shape of the pipe assembly under high pressure.
The strap dimensions are sized to maintain the joint integrity to prevent
fluid
flowing in the pipes from leaking out of the joints. For pipes under six
inches in
diameter, the strap 12 comprises an elongated member that is preferably, but
optionally, flexible, such as a strip of metal strap. The flexibility is only
in one of
three planes in that the strap can bent about its length to coil into a roll
of strap, but is
preferably not flexible along its length and not flexible laterally in the
width of the
strap. Thus, in the plane of the strap material, the strap is stiff and not
flexible, but
out of the plane of the strap the strap can flex and coil into a role or to
conform to the
shape of the pipe joint. The strap is preferably a tension member that does
not bend
sideways or extend its length but it can curve about its length to conform to
the
contour of a pipe joint.
The strap is advantageously less than two inches wide, and preferably about
one to 1.5 inches wide for a strap made of stainless steel. The strap
thickness is
advantageously less than about 1/16 inch thick, and preferably about .03
inches thick
when the strap is made of stainless steel. Depending on the size of the pipe
or the
CA 02697763 2010-03-25
18
pressure of the fluid in the pipe, the strap dimensions will vary. The straps
12i, 12o
are preferably metal straps, but could be multiple thin straps fastened
together by
rivets or banding. Straps 12 made of round or flat metal or non-metal cable,
other
suitably strong and durable material, such as high-tensile polymer webbing or
cord
could also be used, but such straps may be flexible sideways in the plane of
the strap
and that is less desirable since such flexibility may allow the strap to slide
sideways
and move out of the plane passing through the centerline 13 and the strap on
the other
side of the adjacent pipe section 18 or the fitting and thus result in non-
symmetric
resistance of movement on the pipe sections in the pipe joint. The straps 12
are
shown as flat across the width of the strap and curved along the length of the
strap,
but the straps 12 could be slightly curved across the width to better conform
to the
diameter of the pipes 16, 18. Ideally, the straps 12 are curved across the
width of the
strap with a radius of curvature corresponding to the outer diameter of the
pipes 16,
18, and more particularly corresponding to the radial distance from center
axis of flow
path 13 to the outer surface of pipes 16, 18. Since one pipe restraint 10 may
be used
with a range of pipe diameters, the curvature may generally correspond to the
diameter of pipes within that range.
Figs. 1-9 show the straps 12 flat and wide. But the cross-sectional shape is
not
so limited and any shape could be used. The straps 12 are preferably primarily
tension members, since the length between adjacent pipe sections 18 is such
that the
typical straps 12 will buckle if placed in compression rather than tension.
Figs. 10-11
show straps 12 with different cross sectional shape.
The connectors 14 and 15 may require adaptation according to the type of
pipes 16, 18, especially if something other than a straight pipe section is
used for the
first abutting pipe section 18. One or more of the first pipes 18a, 18b could
be a T-
fitting, and end fitting, a Y-fitting, etc., and depending on the
configuration of that
first pipe section 18, it may be more suitable to use bands, ties, lugs, wire
loops,
adhesives or threaded fasteners, in either metal or non-metallic materials, to
connect
the straps 12 to the pipe segments 16, 18.
The type of pipe connectors 14, 15 that are used is not believed critical as
long
as the strap 12 can fasten to it to restrain movement of the sleeve 20 and/or
pipe
segment 18 along flow path axis 13. Hose clamps with opposing free ends joined
by
a tightening mechanism, with the straps 12 connected to the strap between
those ends,
CA 02697763 2016-08-29
19
are preferred. The pipe connectors 14, 15 are typically connected to the
straps 12
between the ends, and preferably near the middle of the circumference of the
pipe
connector. The straps 12 are typically connected by rivets, spot welding,
bolts, or
other fastening mechanisms. The pipe connectors 14, 15 are preferably of
adjustable
length or adjustable diameter so the connectors 14, 15 can clamp or compress
against
the adjacent pipe section 16, 18. Thus, the straps 12 connect to the pipe
connectors
14, 15 roughly opposite the adjustable tightening mechanism that holds
opposing ends
of the connectors 14, 15 and tightens the connectors 14, 15.
Hose clamps having a worm or screw device on a band clamp are useful for
providing variable control over the tightening of the pipe connectors 14, 15,
while
toggle type clamps provide faster attachment and tightening but coarser
adjustment on
the tightening. A hose clamp with a threaded fastener adjustment or worm drive
tightening, on a rotating or toggle type of connector has the advantage of
quick
installation with variable tightening adjustment. Such a fastener is sold
commercially
as the SnaplockTM Quick Release, worm drive clamps. The worm drive is
pivotally
attached to the band, with an arc of motion relative to the attachment point,
such that
at one extreme of the arc the screw threads fully engage the apertures in the
band, and
in the opposite extreme of the arc the screw threads and the apertures are
completely
disengaged. In this manner, the band may be quickly inserted and advanced
through
the passage while the screw device is pivoted away, then captured and
tightened to the
desired extent by pivoting the screw device back into engagement with the
apertures
and rotating the screw thread, e.g., with a hand tool. With the described
pivot
adaptation, the band clamp may therefore be installed quickly and efficiently
around
pipes or other objects of widely-varying sizes. But as noted above, other
clamps are
suitable.
Band clamps of various types are believed especially suited for use as the
clamps 22 and as the pipe connectors 14, 15, with threaded tightening being
preferred,
but with lever clamp tightening also believed suitable. Such clamps are
described and
shown in U.S. Patent Nos. 2,018,906, 2,403,449, 2,990,599, 4,307,495 and
5,010,626,
5,653,481. Briefly described, such band connectors 14, 15 are made of a band
with
apertures along at least a portion of its length, with a threaded screw device
attached
at one end such that the screw axis and the band axis are approximately
parallel, but
slightly
CA 02697763 2010-03-25
offset from each other. The preferred apertures in the band are preferably
about 0.035
to 0.045 wide in the axial direction along the length of the band, with the
material
between the apertures being about 0.06 wide. However, it should be understood
that
other dimensions are possible and may be acceptable so long as the strength
and
5 function of the band meets the functional requirements.
Further, in some versions of connectors 14, 15 comprising ring clamps or hose
clamps that use threaded fasteners or lead screws to tighten the clamps, a
narrow
passage exists between the band encircling the pipe and the tightening screw
that
tightens or loosens the band, so that the free end of the band may be looped
around
10 and interposed through the passage, thus engaging the thread of the
screw. However,
the passage may be too thin to allow the thickness of the band to pass
directly through
without meeting with interference from the screw threads. The apertures in the
band
may be oriented at an angle corresponding to the pitch angle of the screw
threads used
to tighten the band clamp 14, so that the free end of the band may be advanced
15 through the passage only by turning the screw, thereby progressively
tightening the
loop.
As used herein, hose clamp and band clamp are used interchangeably to refer
to the same types and varieties of clamps that encircle sleeve 20 and the
pipes 16, 18
to compress the sleeve against the pipes and form a fluid tight seal. One
skilled in the
20 art will recognize there are a wide variety of such clamps of various
constructions.
The various hose clamps and band clamps and other encircling devices that
compress
sleeve 20 against the pipe sections 16, 18 inside the sleeves 20 comprise
means for
fastening the proximal ends of the sleeves to the ends of the curved section
to form a
fluid tight seal and also comprise means for fastening the distal ends of the
sleeves to
the adjacent pipe sections to form a fluid tight seal.
Referring to Figs. 1-9, the pipe connectors 14, 15 may be fastened to an end
of
strap 12 by any mechanism suitable for the load to be carried by strap 12 and
transmitted to the connector 14. For smaller diameter pipes up to about four
inches in
diameter operating under internal pressures up to perhaps 50 psi to one
hundred psi,
one or more rivets are believed suitable to fasten the strap 12 to the
connector 14. For
larger diameter pipes, stronger connections may be used as discussed later.
The straps
12 can be fastened to or connected to the pipe connectors 14, 15 through any
suitably
strong connection, including threading the straps through apertures, or by
fastening
CA 02697763 2010-03-25
21
the straps 12 to tabs 24 (Figs. 10-11), or by crimping or swaging abutting
parts
together, or by knotting straps made of material suitable for knotting. The
length of
the straps 12i, 12o will vary, but strap 12o is long enough to extend along
the outer
contour of the pipe joint and strap 12i is long enough to form a chord length
across
the inner dimension of the bend, and both straps 12 allow the pipe connectors
14, 15
to fasten to the next segment of the pipe.
Referring to Figs. 14-20, for larger diameter pipes the pipe connectors 14
need
to be fastened more securely to the straps 12 and more than one clamp 22 may
be
used to ensure the joint connections and to help ensure the sealing sleeves 20
do not
leak. For larger diameter pipes the inner strap 12i is made stronger by
altering one or
more of the strap material, width or thickness, or by using more than one
strap and
laying them on top of each other. Likewise, for larger pipes, the pipe
connectors 14,
may be strengthened by increasing the strength of the material, width or
thickness
of the connectors.
15 Preferably, though, the connection of the strap 12 to the
connector(s) 14, 15
for larger pipes uses an adjustable length connector which can tighten or
loosen the
strap 12 and thus increase or decrease the tension in the strap 12 and the
force with
which the pipes 18 are urged toward or against curved pipe 16. Preferably, a
threaded
fastener is connected to one or both ends of the strap 12 with the threaded
fastener
fastened to a connector 14 in a way allowing tightening or loosening of the
strap.
The figures show each distal end of the strap folded back to form a loop of
material enclosing part of a T bolt 30 with a suitably located hole in the
bent-over end
of the strap to accommodate the leg 32 of the T bolt while the strap encircles
the
remaining top of the T bolt. The bent over ends of the inner strap 12 can be
fastened
to the strap by bolts or rivets or spot welds 34 to hold the T bolt 30 in
place. An L
bolt could also be used as could other suitably strong alternative
connections, which
connections may vary with the nature of the strap 12.
The T bolt 30 may have threads 36 formed on at least a portion of the leg 32.
The bolt 30 passes through an opening in the pipe connector 12i with a nut 36
preventing removal and fastening the strap to the connector. The outer strap
12o has a
similar construction, the details of which are not repeated.
Advantageously, to accommodate larger forces in the straps 12, the pipe
connectors 14, 15 may comprise a split ring connector (sometimes called a pipe
clamp
CA 02697763 2010-03-25
22
or riser clamp) having two parts 38L, 38R (Left & Right, respectively), each
of which
has a curved portion 40a, 40b and each of which has two distal end flanges
42a, 42b,
extending generally radially outward. Bolts 42 through holes in the distal end
flanges
42 clamp the aligned flanges together to fasten the connectors 14, 15 to one
of the
pipes 17 and in less desirable situations, to fasten to curved pipe section
16. It is
possible, but less desirable, for the connectors 14, 15 on larger diameter
pipes to also
encircle a portion of the sealing sleeve 20. In use, the pipe connectors may
comprise
hose clamps with diameters of from 2-12 inches, and preferably of 4-10 inches,
and
also from 6-10 inches. Riser clamps may be used with diameters of
The T bolt 30 is fastened to the connector 14, 15. A boss or flange could be
provided on the connector 14, 15. But preferably, at or near the juncture of
the curved
portions 40 and distal flanges 42 of each connector part 38L, 38R, is
preferably (but
optionally) formed a curved or inclined portion 44 which forms a portion of a
passageway through which leg 32 of the T bolt 30 passes, with nut 36 fastening
the
end of the strap 12 to the connector 12. The bolt holding distal flanges 42a,
42b
together is preferably close to t he passageway formed by portions 44. The use
of
threaded bolt 30 and nut 36 allows adjustable tightening of the straps 12 and
thus
adjustable tension in the straps 12 and adjustment of the force with which the
pipes 18
are urged toward the curved pipe 16. Other adjustable length and adjustable
force
connectors are suitable for use with strap(s) 12. There are thus provided
means for
adjusting the length and/or force or tension in the straps 12.
The strap 12 advantageously fastens at or adjacent to the outer surface of the
pipe 16, 18 or at or near the inner or outer surface of sleeve 20 so as to
reduce the
twisting force exerted on the pipe connectors 14, 15 by the strap(s) 12. Figs,
19 and
20 show the outer strap 12o offset from the curved pipe 16- for illustration.
In use,
the strap 12o would push against, contact or abut the outer surface of the
center pipe
16 (directly or through some structure is interposed between the strap and the
pipe).
Putting adjustable length mechanisms on the straps 12 allows the resistance to
pipe separation to be adjusted and allows greater flow rates through the pipes
16, 18
and greater pressures in the pipes to be accommodated without separation and
with no
or acceptable leakage under such pressures. The adjustable length is shown as
achieved by threaded fasteners, but other length adjustments can be used,
included
cam and lever mechanisms mounted to or connected to the pipe connectors 14, 15
and
CA 02697763 2010-03-25
23
also connected to the strap 12. Likewise, threaded fasteners other than the
depicted
configuration could be used, including toggle bolts or shafts with threaded
ends
passing through bosses located on or openings through portions of the pipe
connectors
14, 15.
For smaller diameter pipes 16, 18, the sealing sleeve 20 may optionally have
integrally molded flat steel wires or straps which form ring clamps 22. For
larger
diameter pipes the tubular sealing sleeves 20 typically have multiple ring
clamps 22
integrally molded into the sleeves 20. Such sleeves 20 with integrally molded
ring
clamps 22 are known in the prior art.
While using band clamps or split ring clamps to connect to the pipes 16, 18,
or
to compress sleeves 20 against the pipe sections 16, 18 are the preferred
means for
connecting the ends of straps 12 to the pipe segments 16, 18, various other
means of
attaching the straps 12 to the pipe segments can be used, including threaded
fasteners
passing through the straps or connectors to the pipes 18 or a boss on the
pipes bolted
or otherwise fastened to the straps, spot welding the straps or connectors to
the pipes,
adhesive bonding, rivets, shackles, or loops made of any suitable material
(metal or
non-metal) fastened to the pipes 18. There are thus provided means for
fastening the
straps 12i, 12o to the adjacent pipe sections 18a, and 18b.
Referring to Figs. 19A, 20A and 21, a 45 pipe joint is shown. The location of
the inner and outer straps 12i, 12o, respectively, are as described earlier.
The
remaining parts of the pipe joint 10 are as described earlier and that
description is not
repeated. Fig. 21 shows the pipe connectors 14a, 14b as overlapping outer
strap 12o.
Depending on the configuration of pipe connectors 14 and strap 12o, the pipe
connectors 14 may fit underneath the outer strap 12o or they may pass over
other
strap 12o and push it against the adjacent pipe 18. Preferably the pipe
connectors 15
pass over the outer strap 12o and press the strap against the pipe 18 to help
hold the
outer strap in position.
Referring to Figs. 22-24 an embodiment is shown in which the inner and outer
straps are connected to the same pipe connectors, shown as pipe connectors 38.
The
pipe connector could be as described for connector 14, 15 or for connector 38.
The
location, construction and use of the various parts is as previously described
and is
thus not repeated in detail. The straps 12i and 12o each have distal ends
connecting to
the same pipe connector 38, on opposing sides of the connectors. Adjustable
length
CA 02697763 2010-03-25
24
or tensioning mechanisms on the straps 12 are provided by the threaded leg 32
passing through the pipe connector and held by nut 36 from pulling away from
the
pipe connector 38.
Referring to Figs. 25-27, a T joint or T-fitting is shown in which adjacent
pipe
sections 18a, 18b are joined to opposing ends of a T-fitting 46. Sleeve 20 and
clamps
22 provide a fluid tight connection between adjacent pipe sections 18a, 18b,
as
previously described. In the above pipe joints, the inner strap 12i extended
across
open space between two pipe sections 18 that were inclined relative to each
other,
which outer strap 12o followed the contour of the pipe joint and typically
abutted the
pipe, sleeves and sealing clamps. In the joint of Figs. 25-27, the joined pipe
sections
18 are aligned so the straps 12 are each more akin to the outer straps 12o.
The two
straps 12 are on opposing sides of the pipe joint so the inside and outside
nomenclature for a curved joint is not as apparent, although the straps are
the same as
previously described, as are the remaining parts of the pipe joint. The
repeated parts
of the pipe joint are not again described but the same numbers are used for
the same
parts. For ease of reference the strap closest to the viewer in the first
image will be
referred to as the first strap 48 and the other strap will be referred to as
the second
strap 50. Except for changing the names or numbers, the straps 48, 50 are the
same as
the straps 12. A connector 14 is fastened to each end of first strap 48, and a
connector
15 is fastened to each end of second strap 50. The connectors 14, 15 are as
described
above and can include the split ring connector and other connector variations.
The T fitting 46 forms a straight flow axis along longitudinal axis 13, and
the
length of the straps 48, 50 are preferably in the same plane as the centerline
of that
flow path and longitudinal axis, on diametrically opposing sides of the pipes
18a, 46,
18b. First strap 48 is thus shown, with second strap 50 on the opposing side
but not
readily visible in the figures but opposite to the first strap. The pipe
connectors are
staggered, so that each strap 48, 50 is slightly offset along the length of
the
longitudinal axis 13. This allows the straps 48, 50 to be the same length.
Alternatively, one strap 48, 50 could be shorter so both of its pipe
connectors 14 or 15
could fit inside the other pipe connectors 15 or 14. The strap 48, 50 on the
most distal
connector 14, 15, the one closest to the adjacent end of pipe section 18a,
18b,
preferably overlaps the strap connected to the less distal connector.
CA 02697763 2010-03-25
As in the other embodiments, the straps 48, 50 restrain the adjacent pipe
sections 18a, 18b from moving away from the T fitting 46. In this
configuration the
straps restrain opposing sides of each adjacent pipe section 18a, 18b. If the
straps 48,
50 do not fasten to the pipe sections 18 on diametrically opposing sides, then
the pipe
5 sections 18 may tilt under pressure, leading to leakage or joint
separation. While not
shown, any of the adjustable connector discussed herein which vary the length
of the
straps 48, 50 or the tension in those straps, can also be used. In this pipe
joint, the
centerline of the flow path 13 is substantially straight and the straps 48
form first and
second straps that are substantially parallel along a substantial portion of
the length of
10 the first and second straps. Substantial means half or more.
Referring to Figs 28-30, a San-Tee pipe joint using San-Tee connector 52 is
shown joined to adjacent pipe sections 18a and 18b centered on longitudinal
axis 13,
and perpendicular pipe section 18c which is orthogonal to the flow path along
axis 13
and which extends along axis 53. Sleeves 20 and clamps 22 join the adjacent
pipe
15 sections 18a, 18b, and 18c to the three ends on the San-Tee connector
52. A first
strap 48 has a first connected to a first connector 14a that encircles and
engages (or
otherwise connected to) adjacent pipe 18a. Strap 48 has a second end 50
connected to
a second connector 14b that encircles and engages (or is otherwise connected
to)
adjacent pipe 18b. The connectors 14 could encircle and fasten to the sleeves
20, but
20 that is not preferable. The depicted strap 48 for the San-Tee joint has
pipe connectors
14a, 14b toward the distal ends of the adjacent pipe sections 18a, 18b, but
the
connectors could be on the sleeves 20 or next to the sleeves on the proximal
ends of
the pipe sections.
A second strap 50 has a first connector 15a that encircles and engages (or is
25 otherwise connected to) the perpendicular portion 54 of the San-Tee
section 52. It is
possible, but not shown, to have an inner strap 12i extend between the
perpendicular
portion 54 and adjacent section 18a or 18b.
The first strap 48 has a length that extends along the center of flow path 13
is
that is preferably also in the plane through axes 13, 53. That location is
believed to
reduce twisting or canting of the adjacent pipe sections 18a, 18b caused by
the strap
48. Likewise, second strap 50 preferably extends along a line parallel to the
center of
flow path 53, and advantageously is in the plane thorough axes 13, 53.
Alternatively,
it is believed suitable to have second strap 50 located in a plane orthogonal
to flow
CA 02697763 2010-03-25
26
axis 13 and containing axis 53, and extend from one side of the adjacent pipe
section
18c, around the curved portion of San-Tee fitting 52, and fasten to the same
pipe
connector 15a or 15b. In this alternative configuration both ends of the strap
50 attach
to the same pipe connector.
In use, the straps 48, 50 help maintain the position of the pipe sections 18
relative to fitting 52 and restrain movement of the adjacent pipe sections
away from
the San-Tee fitting 52. The location of the straps 48, 50 are preferable such
that the
forces on the adjacent pipe segments 18 are symmetrical and/or reduce canting.
The
straps 48, 50 on the San-Tee fitting 52 are not symmetrical and that is
because flow
direction causes tilting in the direction opposed by the straps 48, 50. It is
advantageous to provide further straps from the adjacent pipe section I8c to
the fitting
52 or the adjacent sections 18a, 18b, but that is optional.
Referring to Figs. 31-33, a reducer pipe fitting 62 is shown in which pipes of
larger and smaller diameters are joined by a reducer fitting 62. The reduction
pipe
joint 56 has a first larger diameter end 58 sized to fit a larger pipeline,
and a smaller
diameter end 60 sized to fit a smaller diameter pipeline. A flat or tapered
transition
section 62 connects the two diameters. The flow is usually from the larger
diameter
to the smaller diameter pipe. A larger diameter adjacent pipe section 18a is
connected
to the larger diameter end 58 of the reducer fitting 62 by a larger diameter
sleeve 20
and clamps 22. A smaller diameter sleeve 20 and clamps couple the smaller
diameter
end 60 of the reducer 56 to the smaller diameter adjacent pipe section 18b.
The arrangement is much like that of the straight pipe section of Fig. 27
except
that the straps 48, 50 bend to conform to the change in diameter of the joined
pipe
sections. First strap 48 has a first end connected to first clamp 14a that
encircles or
otherwise joins to adjacent pipe segment 18a. Strap 48 has a second end
connected to
a second clamp 14b that encircles or otherwise joins to adjacent pipe segment
18a.
Opposite strap 48 is strap 50, with pipe connector 15a connected to the larger
pipe
section 18a. Pipe connector 15b connects to the smaller pipe section 18b. In
the
depicted embodiment the straps 48, 50 are staggered so the strap 48 is closer
to the
transition section 62 at the larger end of the pipe 18a but further from the
transition
section at the smaller end 18b, with the pipe connector 15b encircling and
located on
top of the strap 48 at the smaller diameter end 18b.
CA 02697763 2010-03-25
27
The Straps 48, 50 each bend at the reduction in diameter at transition section
62 where the larger diameter of pipe section 18a ends and the reduction in
diameter
accompanying transition section 62 begins. Thus, each strap 48, 50 is on the
inside of
a pipe connector on the other strap, at one end of the pipe joint. In this
embodiment,
the flow path centerline 13 is substantially straight and the first and second
straps 48,
50 are substantially parallel for a portion of the length of the straps (along
the larger
diameter pipe section 18a), and are inclined toward each other for a portion
of the
length of the straps (across transition fitting 62.
Referring to Figs. 34-36, an end of line plug or blind cover 64 has sleeve 20
and clamps 22 fastening the blind cover 64 to the pipe 18b. The blind cover 64
can
take various forms and is shown here as a cup-shaped piece that fits over the
end of
the pipe section 18b and is clamped to the pipe section 18b by clamps 22. The
cover
64 could take other forms, including a disc-shaped part with a threaded
periphery or
stepped periphery that mates with the end of pipe section 18b in which case
the sleeve
20 and clamps 22 may be omitted. Strap 48, having a connectors 14a, 14b at
opposing ends of the strap, passes over the end of the pipe section 18b
blocked by
blind cover 64 to restrain that cover 64 from moving along flow path 13. The
pipe
connectors 14a, 14b are adjacent each other and staggered so one strap is
closer to the
end of pipe section 18b than the other pipe connector, with one pipe connector
encircling a portion of the strap 48 and pressing it against the outer surface
of the pipe
section 18b. Note that the flow path ends at the blind cover 64 when the cover
is in
place, but that a flow path is still defined to the blind cover and may pass
the blind
cover when the cover is removed, as for cleaning or access to the pipeline.
A second strap 50 (not shown) could be used if additional restraining force is
needed, with the second strap orientated 90 degrees relative to the first
strap 48.
Advantageously, the strap 48 (or 50) has a length or tension adjusting device
described earlier, but not shown in Figs. 34-36. Thus, the amount of
restraining force
on the end of the blind section 64 can be adjusted by such tension adjusting
mechanisms and means.
Referring to Figs. 37-39, a Y fitting or wye fitting 66 is shown with first
and
second branches 68, 70 and a leg or base section, each of which is connected
to an
adjacent pipe section 18a, 18b and 18c by sleeves 20 and fittings 22 as
described
above. Pipe sections 18a and 18b are on the same substantially straight flow
path
CA 02697763 2010-03-25
28
along centerline 13. Typically, the branches of the Y fitting 66 are about 45
degrees
apart, but the angles can vary. In the depicted Y fitting, there is a straight
through
flow path along axis 13 and one branch at 450 to that flow path along axis 53.
Preferably, but optionally, each adjacent pipe section 18a, 18b, 18c has two
opposing straps 48, 50 restraining the pipe section from moving away from the
Y pipe
fitting 66 under fluid pressure, or from tilting or canting away from the flow
axis
under pressure. Each strap has a pipe connector 14a, 14b or 15a, 15b at each
end of
the strap, where the connectors are described as above. Because of the
geometry,
some of the straps may connect to one of an adjacent pipe section 18a, 18b,
18c, or
they may connect to the joint fitting 66. The pipe straps and fittings have
the
construction as described above and elsewhere herein, and the details of that
construction are not repeated.
First strap 68 extends along between adjacent pipe sections 18a, 18b on flow
axis 13, with first pipe connector 15a connecting to adjacent pipe section
18a, and
second pipe connector 15b connecting to adjacent pipe segment 18b. The first
strap
68 extends along the two pipe sections 18a, 18b and along the fitting 66, and
could
optionally be connected to the fitting as described above. Second strap 70
extends
from first adjacent pipe section 18a to the third adjacent pipe section 18c,
with pipe
connectors 14a, 14b encircling or otherwise connected to adjacent pipe
sections 18a
and 18c, respectively. The strap 70 corresponds to an inner strap 12i since it
extends
between two adjacent pipe sections 18a, 18c that are inclined to each other
and strap
68 corresponds to outer strap 12o since it follows the outer periphery of the
adjacent
pipe sections 18a, 18b and the intervening pipe fitting 66.
Diametrically opposite the connection of second strap 70 with third adjacent
pipe section 18c, is a third strap 72, extending along adjacent pipe section
18c to
fasten to the wye fitting or fitting 66. Pipe fittings 15a, 15b extend from
the same side
of strap 72. Pipe fitting 15b encircles the end of strap 70 next to the pipe
connector
14b. Depending on the ordering of the straps and the adjustment or tightening
mechanisms, different straps may pass underneath different pipe connectors.
Diametrically opposite the connection of first strap 68 to the adjacent pipe
section 18b, is fourth strap 74 which extending along the second adjacent pipe
section
18b to the fitting 66. Pipe connectors 14 or 15 on each end of strap 74 couple
the
respective ends of the strap 74 to the adjacent pipe section or fitting. In
the depicted
CA 02697763 2010-03-25
29
embodiment the strap 74 has one end connected to pipe connector 14b which
encircles adjacent pipe section 18b, and the other end is connected to pipe
connector
14a which encircles the other branch of the Y fitting 66 and its associated
central path
53. The pipe connector 14a encircles and passes over part of the strap 72.
The strap 74 corresponds to an inner strap 12i since it extends across a gap
or
space between an adjacent pipe section 18c and a branch of fitting 66, and
strap 72
corresponds to outer strap 12o since it follows the outer periphery of the
adjacent pipe
section 18c and its juncture with pipe fitting 66.
All of the straps 68, 70, 72, 74 preferably have the length of the strap
located
in the plane passing through centerlines of the flow paths of axes 13 and 53.
That
way each adjacent pipe section 18a, 18b, 18c is urged against or toward
fitting 66 by
symmetric forces. Advantageously, but optionally, the straps 66, 70, 72, 74
have
length adjustment mechanisms on them to vary the force or length in the
respective
straps. It is believed that the straps 70, and possibly straps 72 and 74,
could be
omitted, depending on the orientation of the Y fitting 66 and the flow through
the
fitting.
Referring to Figs. 40-42, the Y or wye pipe fitting 66 is shown with a
straight
pipe section 18a, 18b connected to the pipe fitting 66 along straight flow
path 13.
Curved pipe fitting 16 (1/8 bend) connects to the other branch of the Y
fitting 66, with
a straight pipe section 18c connected to the curved fitting 16 so that the
flow path
through that branch along centerline axis 53 is ultimately perpendicular to
flow path
13. Tubular sleeves 20 and clamps 22 provide fluid tight seals across the
various pipe
joints.
First strap 68 has first pipe connector 15a (left end) encircling or otherwise
connected to first adjacent pipe section 18a. At the opposing end of strap 68
is second
pipe connector 15b encircling or otherwise connected to second adjacent pipe
section
18b. Strap 68 passes along and could optionally be fastened to fitting 66. The
second
adjacent pipe section 18b is also connected to the other branch of the Y
fitting 66 by
strap 76 with one pipe connector 14a on end 18b, and the other pipe connector
14b
encircling the other branch of the Y fitting 66, with strap 76 extending
between those
pipe connectors. The strap 76 and connectors 14a, 14b are analogous to the
inner
strap 12o since it spans the space between parts, while strap 68 is analogous
to strap
12o and its connectors 15a, 15b which follows the contour of the pipe joint.
CA 02697763 2010-03-25
Diametrically opposite strap 68 is strap 70 which connects to first adjacent
pipe section 18a and the inclined branch of the Y fitting 66 through pipe
connectors
14a (on pipe section 18a) and 14b (on fitting 66). The strap 70 and pipe
connectors
14 correspond to inner strap 12i since it extends across a space between parts
of the
5 pipe joint.
A third strap 72 connects the branch of the Y fitting 66 to the third pipe
section 18c, through pipe connectors 14a, 14b, respectively, each encircling
or
otherwise connected to the pipe fitting 66 and pipe section 18c, respectively.
The
pipe connector 14a on this strap 72 passes over the strap 70 as best seen in
Fig 40.
10 Diametrically opposite and substantially parallel to strap 72 is fourth
strap 74
extending between the adjacent pipe section 18c and the wye fitting 66,
through pipe
connectors 15a, 15b. The straps 72, 74 correspond to straps 12i and 12o in the
above
described embodiments. A fifth strap 76 described above is provided between
the
pipe section 18b and the adjacent branch of the Y fitting 66. The pipe
connector 14b
15 on strap 76 passes over the strap 74.
The straps 68, 70, 72, 74 and 76 preferably have a length extending in a
common plane, which plane also contains flow axes 13, 53. As with the other
embodiments, the straps and connectors urge the adjacent pipe sections 18 (and
any
intervening pipe fittings) toward the main pipe fitting (here Y fitting 66) to
prevent or
20 reduce splaying or movement of pipe sections away from the main fitting
and thereby
reduce leakage and/or breakage of the pipe joint. It is believed that straps
70 and 74
could be omitted in this embodiment, depending on the orientation of the Y
fitting 66
and the associated pressures in the pipe joint. It is believed that a single
strap with
three pipe connectors could be used to replace straps 70, 72.
25 Referring to Figs. 43-45, the Y or wye pipe fitting 66 is shown as
described in
Figs. 40-42, but with a blind end 64 instead of the straight pipe section 18b
connected
to the pipe fitting 66 along straight flow path 13. First strap 68 has first
pipe
connector 15a encircling or otherwise connected to first adjacent pipe section
18a. At
the opposing end of strap 68 is second pipe connector 15b encircling or
otherwise
30 connected to second adjacent pipe section 18b, which in this instance
has a blind plug
or blind end 64. Strap 68 passes along and could optionally be fastened to
fitting 66.
The blind end cap or plug 64 is also held closed by strap 68. The pipe
connector 15b
connects to the end of strap 68 (e.g., rivet) at a location between the two
branches of
CA 02697763 2016-08-29
31
the Y fitting, with the strap 68 passing over the end plug 64 (Fig. 45) and
two
opposing sides of the associated sealing sleeve 20, and then passes underneath
the
pipe connector 15b before extending across pipe fitting 66 to reach first pipe
section
18a and its pipe connector 15a. The pipe connector 15b encircles or is
otherwise
connected to one branch of the Y fitting 66. The remaining parts may be as
described
regarding Figs. 40-42.
There is thus provided a pipe joint in which one of the adjacent pipe sections
comprises a blind end 64. The pipe connector 15b is connected adjacent an
outlet of
the pipe fitting 66 leading to the blind end 64, and the strap 68 crosses the
blind end
64 and ends at the pipe connector 15a.
The straps and fittings provide means for restraining or limiting movement of
pipe sections 18 or joined pipe fittings (e.g., 66 and 16) relative to a main
pipe fitting
16, 66. The straps advantageously include an adjustable length mechanism to
vary
the tension or force exerted by the strap that resists movement of the pipe
sections 18
or pipe fittings 16 to which the straps are connected. The pipe fittings 14,
15
preferably are also of adjustable length (or circumference or diameter) to
allow the
connectors to be used with variable diameter pipes, to fit over the ends of
pipes,
fittings and sleeves readily, and to compress sleeves 20 to assist in sealing
if desired
or if tight spacing requires placing the connector on a sleeve. Each of the
straps (12,
48, 50, 68-76) has a length extending in a plane through a centerline (13, 53)
of the
flow path through the pipe joint.
The various features of the embodiments disclosed herein can be used alone,
or in varying combinations with each other and are not intended to be limited
to the
specific combination described herein. Thus, the scope of the claims is not to
be
limited by the illustrated embodiments.
