Note: Descriptions are shown in the official language in which they were submitted.
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CHECK VALVE
FIELD OF THE INVENTION
The invention relates to check valves, and in
particular to valves used to prevent backflow through fluid-
conducting passages.
BACKGROUND OF THE INVENTION
Particularly in the plumbing and waterworks
industries, situations frequently arise where it is important
to ensure that fluid flows through a conduit in only one
direction. Such a result is often achieved by introducing a
check valve into the conduit. Check valves utilize any of a
variety of valve mechanisms including balls, flaps, swing
doors, and poppets to allow fluid to flow through the valve in
one direction, but not the other.
Poppet-style valves are frequently used for such
applications because they tend to be simple, durable, reliable
and compact. Such valves comprise a valve seat defining a bore
therethrough, a poppet having a poppet face parallel to the
valve seat and having a front side adapted to cover the valve
seat bore when the valve is in its closed position as well as a
poppet stem extending perpendicularly from said poppet face,
and a poppet support adapted to receive the poppet stem for
reciprocal movement therein between a closed position in which
the poppet face is held against the valve seat and an open
position in which the poppet face is spaced from the valve seat
permitting fluid flow around the periphery of the poppet face.
Typically, the poppet is biased towards its closed position
such that its face seats against the valve seat when no flow
exists through the valve. When the fluid pressure against a
back side of the poppet face is greater than that on its front
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side, this pressure differential tends to hold the poppet
tightly against the valve seat thereby increasing the sealing
force. When the fluid pressure on the front side of the poppet
face exceeds the fluid pressure on its back side by an amount
sufficient to overcome the biasing of the poppet towards the
valve seat, the poppet moves away from the valve seat allowing
for fluid flow through the valve.
One exemplary situation in which such unidirectional
flow is desirable is in a residential or commercial water
supply application. In such an application, it is often
desirable to allow water to flow from the municipal water
supply (water main) into the building water system but not vice
versa. This is because should water flow from the building to
the water main (which can occur when there is a pressure drop
in the water main caused by, for example, a broken water main
or burst fire hydrant), the municipal water supply can be
contaminated with water from the building. One manner in which
unidirectional flow in such an application can be achieved is
through the introduction of a check valve between the municipal
water supply and the building water system.
Many existing check valves however are found to be
inadequate for use in such applications because they are not
sufficiently compact, or have too many parts resulting in
difficulties during installation, inspection and servicing.
Further, most existing check valves are single-check
valves in that they possess only a single set of valve
components, such that should one or more of these components
fail, there is no backup feature to prevent backflow. One
solution to this problem is to use multiple sets of valve
components in series, see for example United States Patent No.
5,148,828. However, the use of such multiple sets of valve
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components increases the number of parts to be handled and also
increases the required length of the check valve.
Additionally, as municipal standards for backflow
prevention become more stringent, there arises a need to
retrofit existing plumbing in order to introduce a check valve
between the municipal water supply and the building water
system. The most convenient location in which to introduce
such a check valve is to replace a conventional elbow joint
with one containing check valve components. In many
applications, the elbow joint replaced is one which directs
water from a horizontal pipe connected to the municipal water
supply, down through a vertical pipe connected to the building
water system. However, existing elbow check valve devices are
often too bulky to fit within the existing piping to be
retrofitted. Most often, valve components are contained within
the bottom of the vertical bore of the elbow check valve,
thereby necessitating a longer vertical bore. The existing
piping may not accommodate such a lengthy vertical bore,
necessitating additional retrofitting steps. Of course
compactness of a check valve is a desirable trait regardless of
whether it is used in such a specific retrofitting example,
other retrofitting situations, or indeed non-retrofitting
applications.
Finally, when used within a valve body (a hollow body
intended to house the valve components) valve components can be
held in place by a variety of means. For example, the valve
components may have an external feature that locks into place
on an inner surface of the valve body. However, these methods
of retaining the valve components in place in a valve body are
not satisfactory as they require special features to be
machined into the interior of the valve body, and also do not
allow for the easy removal and insertion of the valve
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components. One solution to this problem is demonstrated by
United States Patent No. 5,148,828, wherein a cage is used for
retaining check valve components in place in the valve body.
However, the cage disclosed in this patent is only adapted to
maintain valve components in the bottom of the vertical bore of
the elbow valve. Additionally, there is no easy means of
ensuring that the cage is oriented in a direction which
maximizes flow through the valve.
SUMMARY OF THE INVENTION
This invention provides an improved valve cartridge
and check valve, which seeks to address one or more of the
problems noted above.
In accordance with a broad aspect, the present
invention provides a valve cartridge for use in a valve body
having a redundant dual-check feature, the valve cartridge
being a single unit containing all components necessary for the
valve cartridge to function as a valve when placed in the valve
body, and wherein all of these components are either integral
with, attached to, contained within one another, or are
otherwise connected such that the cartridge remains unitary
during handling prior to insertion into the valve body.
In other aspects, the valve cartridge has two
independently-operating valves offering redundant protection,
each of the two valves being poppet-style with a valve seat,
poppet (having a poppet face and a poppet stem) and poppet
support. Compactness of the valve cartridge is enhanced by
integrating the poppet support of the first valve and the valve
seat of the second valve, and by allowing the two poppets to
nest within one another when one of the valves is open and the
other is closed. Further, the major components of the valve
cartridge (the first valve seat, the first poppet support /
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second valve seat, and the second poppet support) are locked
together, resisting both separation as well as relative
rotation therebetween.
In accordance with another broad aspect, the
invention provides a check valve comprising a valve body having
an inlet passage adapted to be fluidly coupled to a fluid
source, an outlet passage adapted to be fluidly coupled to a
fluid outlet, and a main body chamber positioned therebetween
and in fluid connection with both the inlet passage and the
outlet passage, a valve cartridge seated substantially within
the inlet passage, the valve cartridge having an upstream end
and a downstream end and being adapted to permit fluid flow
from the fluid source to the main body chamber but to resist
fluid flow from the main body chamber to the fluid source, and
valve cartridge retaining means for retaining the valve
cartridge within the inlet passage, wherein the valve cartridge
retaining means comprises a retaining cage in the main body
chamber.
In other aspects, the retaining cage has an open-
lattice structure to provide structural support to a cartridge-
retaining face which abuts a downstream end of the valve
cartridge and to allow flow of fluid therethrough, and both the
valve cartridge and the retaining cage have features which
allow them only to be inserted into the valve body in their
correct orientations.
Other features of the invention will be understood
from the detailed description of preferred embodiments of the
invention below and from the drawings attached hereto.
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BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention will now be
described with reference to the attached drawings in which:
Figures 1A and 1B are, respectively, perspective and
perspective exploded views of a valve cartridge in accordance
with a preferred embodiment of the present invention;
Figures 2A and 2B are, respectively, perspective and
cross-sectional side views of a first valve seat of the valve
cartridge of Figure 1A;
Figures 3A and 3B are, respectively, cross-sectional
side and downstream views of a first poppet of the valve
cartridge of Figure 1A;
Figures 4A and 4B are, respectively, perspective and
cross-sectional side views of a first poppet support of the
valve cartridge of Figure lA;
Figures 5A and 5B are, respectively, a cross-
sectional side and downstream views of a second poppet of the
valve cartridge of Figure 1A;
Figures 6A and 6B are, respectively, perspective and
cross-sectional side views of a second poppet support of the
valve cartridge of Figure 1A;
Figures 7A and 7B are cross-sectional side views of
the valve cartridge of Figure 1A in its closed and open
positions, respectively;
Figure 8 is a perspective exploded view of the valve
cartridge of Figure 1A in the context of a check valve in
accordance with a second aspect of the present invention;
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Figure 9 is a cross-sectional side view of a valve
body of the check valve of Figure 8;
Figure 10 is a perspective view of a retaining cage
of the check valve of Figure 8; and
Figure 11 is a cross-sectional side view of the check
valve of Figure 8.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of a valve cartridge of the
present invention will now be described in a very specific
exemplary context, namely its use in an elbow-style check valve
to permit flow from a horizontal pipe connected to a municipal
water supply to a vertical pipe connected to a building water
system, but not vice versa.
In this description and in the claims, the term
"valve cartridge" is used to describe a collection of valve
components which together function as a valve when placed
within a valve body. The term "self-contained" when used to
describe a valve cartridge refers to the valve cartridge being
a single unit containing all components necessary for the valve
cartridge to function as a valve when placed in a valve body,
and wherein all of these components are either integral with,
attached to, contained within one another, or are otherwise
connected such that the cartridge remains unitary during
handling prior to insertion into the valve body.
The terms "axial" and "axially" are used to describe
a direction parallel to a centerline of the valve cartridge,
and the terms "radial" and "radially" are used to describe a
direction perpendicular to and extending from the centerline of
the valve cartridge. Further, "upstream" is used to describe
features which are located nearer an end of the valve cartridge
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from which fluid is intended to flow through the valve
cartridge whereas "downstream" is used to describe features
located nearer an end of the valve cartridge to which fluid is
intended to flow through the valve cartridge. "Locked" refers
to two or more components which are attached and resist
separation. Finally, "integral" refers to a single continuous
piece of material.
As shown in Figures 1A and 1B, the preferred
embodiment self-contained dual-check valve cartridge 14 has an
upstream end 185 and a downstream end 190, and broadly
comprises a first valve 150 upstream of a second valve 160.
The first and second valves 150, 160 provide the valve
cartridge 14 with a dual-check feature by functioning
independently of one another and thereby providing redundant
protection against backflow through the valve cartridge 14.
The major components of the first valve 150 are a
first valve seat 18, a first poppet 24, a first poppet support
35 and a first spring 175 interposed between the first poppet
24 and the first poppet support 35. The second valve 160
largely consists of a second valve seat 50 formed on a
downstream surface of the first poppet support 35, a second
poppet 80, a second poppet support 105 and a second spring 180
interposed between the second poppet 80 and the second poppet
support 105. Each of these broad elements of the first and
second valves 150, 160 will now be discussed in turn.
The first valve seat 18 of the preferred embodiment,
illustrated in detail in Figures 2A and 2B, is an annular ring
defining a bore 19 therethrough, and having a valve seat
portion 18a and a connection sleeve portion 18b.
The valve seat portion 18a has an annular radially-
inward projection 15 which slants downstream. A downstream
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surface of this projection 15 defines a first valve seat
surface 22 against which a poppet seal 26 of the first poppet
24 presses when the first valve 150 is in its closed position.
An internal diameter of the connection sleeve portion
18b of the first valve seat 18 is greater than that of the
first valve seat surface 22, such that when the first poppet 24
is in its open position, a flow passage is created between a
periphery of the first poppet 24 and an interior surface of the
connection sleeve portion 18b of the first valve seat 18.
The connection sleeve portion 18b of the first valve
seat 18 has two annular grooves defined on its outer surface.
The first is a first valve seat 0-ring groove 20 adapted to
accept a first valve seat 0-ring 195 which forms a seal between
the first valve seat 18 and a valve body wall when the valve
cartridge 14 is inserted within a valve body 16 as discussed
further below. Downstream of the first valve seat 0-ring
groove 20 is a first valve seat connecting groove 23 adapted to
accept in locking relationship, an inwardly-projecting
connection ridge 42 of an upstream connection flange 55a of the
first poppet support 35. Spaced circumferentially within the
first valve seat connecting groove 23 are four first valve seat
alignment tabs 21. As discussed further below, the first valve
seat connecting groove 23 and first valve seat alignment tabs
21 function to connect the first valve seat 18 to the first
poppet support 35, to align it therewith, and to resist
separation and relative rotation therebetween once locked
together.
The first poppet 24, as shown in detail in Figures 3A
and 3B, comprises a poppet face 25 with a poppet stem 30
extending downstream from the center thereof, an annular
spring-retention flange 34 extending downstream near a
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periphery of the poppet face 25, an annular seal-retention web
29 extending radially outwardly from a downstream end of the
spring-retention flange 34, and an annular flow-direction
flange 28 extending downstream from a periphery of the spring-
retention web 29.
The poppet face 25 of the first poppet 24 has a
slightly conical upstream surface to direct fluid towards the
periphery of the poppet face 25. An outer diameter of the
poppet face 25 is sized so as to fit within the first valve
seat surface 22.
The poppet stem 30 of the first poppet 24 extends
downstream from the centre of the poppet face 25 and has four
longitudinal large splines 31 spaced circumferentially on its
outside surface. Spaced between the large splines 31 are four
small splines 32 each of which extend radially from the poppet
stem 30 to a lesser extent than the large splines 31. As
discussed in greater detail below, the large splines 31 serve
to prevent relative rotation between the first poppet 24 and
the first poppet support 35 while the small splines 32 reduce
the contact surface area between the poppet stem 30 of the
first poppet 24 and the first poppet support 35 thereby
reducing friction therebetween.
Extending downstream near the periphery of the poppet
face 25 of the first poppet 24, coaxial with and surrounding a
portion of the poppet stem 30, is the spring-retention flange
34. The spring-retention flange 34 is spaced from the poppet
stem 30 so as to accommodate the first spring 175 therebetween.
The seal-retention web 29 of the first poppet 24 is
spaced downstream from the poppet face 25 so as to accommodate
the annular poppet seal 26 in a seal recess 27 therebetween.
The outer diameter of the poppet face 25 is less than an outer
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diameter of the seal-retention web 29 so as to allow, during
assembly of the valve cartridge 14, the poppet seal 26 to be
slipped over the poppet face 25 and into the seal recess 27.
Additionally, the outer diameter of the poppet face 25 being
smaller than the diameter of the first valve seat surface 22,
and the outer diameter of the seal-retention web 29 being
greater than the diameter of the first valve seat surface 22
allows the poppet seal 26 to contact the first valve seat
surface 22, and also allows the seal-retention web 29 to
support the poppet seal 26 against the first valve seat surface
22.
The flow-direction flange 28 of the first poppet 24
has compression notches 33 spaced circumferentially therearound
which accommodate support spokes 38 of the first poppet support
35, when the first valve 150 is in its open position, thereby
reducing the necessary overall length of the valve cartridge
14.
The first poppet support 35, as seen in detail in
Figures 4A and 4B, broadly consists of a guide sleeve 36,
support spokes 38, a support rim 40, an upstream connection
flange 55a and a downstream connection flange 55b.
The guide sleeve 36 of the first poppet support 35
defines a longitudinal bore 39 therethrough which receives the
poppet stem 30 of the first poppet 24 during assembly of the
valve cartridge 14. The guide sleeve 36 guides reciprocal
axial movement of the first poppet 24 relative to the first
poppet support 35. The guide sleeve bore 39 is sized so as to
accommodate the poppet stem 30 of the first poppet 24 and the
small splines 32 thereon. The longitudinal bore 39 of the
guide sleeve 36 also has defined therein four longitudinal
alignment slots 41, circumferentially spaced so as to
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accommodate the four large splines 31 of the poppet stem 30 of
the first poppet 24. When the poppet stem 30 is inserted into
the bore 39 of the guide sleeve 36, the large splines 31 co-
operate with the alignment slots 41 to prevent relative
rotation between the first poppet 24 and the first poppet
support 35. Further, the small splines 32 provide a reduced
contact area between the poppet stem 30 and the poppet guide
sleeve 36, reducing friction during axial movement of the first
poppet 24.
Extending radially outwardly from a downstream end of
the guide sleeve 36 of the first poppet support 35 is an
annular spring support web 36a and extending upstream from a
periphery of the spring support web 36a is a spring retention
flange 36b. When the valve cartridge 14 is assembled, the
first spring 175 is compressed between the downstream surface
of the poppet face 25 of the first poppet 24 and the spring
support web 36a of the first poppet support 35. The first
spring 175 is held in place by the poppet stem 30 and the
spring retention flange 34 of the first poppet 24 at one end,
and the guide sleeve 36 and spring retention flange 36b of the
first poppet support 35 at the other.
Support spokes 38 extend radially outwardly from the
spring retention flange 36b of the first poppet support 35 and
connect the guide sleeve 36 with the support rim 40. The
support spokes 38 ensure that the guide sleeve 36 is positioned
and maintained centrally within the support rim 40, and that
the longitudinal bore 39 through the guide sleeve 36 is coaxial
with the remainder of the valve cartridge 14. The support
spokes 38 are spaced circumferentially so as to engage the
compression notches 33 of the flow-direction flange 28 of the
first poppet 24 to maximize the amount of compression of the
first spring 175 when the first valve 150 is in its open
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position. Spaces between the support spokes 38 define flow
passages 37 through the first poppet support 35.
Extending downstream from a radially inward
downstream portion of the support rim 40 of the first poppet
support 35 is an annular protrusion which forms the second
valve seat 50 against which the poppet seal 86 of the second
poppet 80 presses when the second valve 160 is in its closed
position.
The upstream connection flange 55a extends upstream
from, and the downstream connection flange 55b extends
downstream from, a peripheral surface of the support rim 40.
The upstream connection flange 55a has an inwardly-
projecting connection ridge 42 at an upstream end thereof for
engaging the connecting groove 23 of the first valve seat 18
when the valve cartridge 14 is assembled. The connection ridge
42 of the upstream connection flange 55a also has defined
therein, upstream connecting groove notches 44 sized and spaced
circumferentially to accommodate the first valve seat alignment
tabs 21 of the first valve seat connecting groove 23.
Similarly, the downstream connection flange 55b has
an inwardly-projecting connection ridge 43 at a downstream end
thereof for engaging a connecting groove 107 of the second
poppet support 105 when the valve cartridge 14 is assembled.
The connection ridge 43 of the downstream connection flange 55b
also has defined therein, downstream connecting groove notches
45, sized and spaced circumferentially to accommodate second
poppet support alignment tabs 108 of the second poppet support
connecting groove 107, as further discussed below.
Between the upstream and downstream connection
flanges 55a, 55b of the first poppet support 35 is defined an
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annular 0-ring groove 56 adapted to accommodate an 0-ring 57.
The 0-ring 57 forms a seal between the first poppet support 35
and the valve body wall when the valve cartridge 14 is inserted
within the valve body 16 as discussed further below.
Turning now to the second valve 160, as discussed
above the second valve seat 50 is formed on a downstream
surface of the first poppet support 35.
The second poppet 80, as shown in detail in Figures
5A and 5B, comprises a poppet face 85 with a poppet stem 90
extending downstream from the center thereof, an annular
spring-retention flange 81 extending downstream near a
periphery of the poppet face 85, an annular seal-retention web
89 extending radially outwardly from a downstream end of the
spring-retention flange 81, and an annular flow-direction
flange 88 extending downstream from a periphery of the spring-
retention web 89.
An upstream surface of the poppet face 85 of the
second poppet 80 has an indent 82 defined therein to
accommodate the poppet stem 30 of the first poppet 24 when the
first valve 150 is open and the second valve 160 is closed.
This feature assists in allowing the valve cartridge 14 to be
compact in length. An outer diameter of the poppet face 85 is
sized so as to fit within the second valve seat 50.
The poppet stem 90 of the second poppet 80 extends
downstream from the centre of the poppet face 85 and has four
longitudinal large splines 92 spaced circumferentially on its
outside surface. Spaced between the large splines 92 are four
small splines 91 each of which extend radially from the poppet
stem 85 to a lesser extent than the large splines 92. As
discussed in detail below, the large splines 92 serve to
prevent relative rotation between the second poppet 80 and the
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second poppet support 105 while the small splines 91 reduce the
contact surface area between the second poppet poppet stem 90
and the second poppet support 105 thereby reducing friction
therebetween.
Extending downstream near the periphery of the poppet
face 85 of the second poppet 80, coaxial with and surrounding a
portion of the poppet stem 90, is the spring-retention flange
81. The spring-retention flange 81 is spaced from the poppet
stem 90 so as to accommodate the second spring 180
therebetween.
The seal-retention web 89 of the second poppet 80 is
spaced downstream from the poppet face 85 so as to accommodate
the annular second poppet poppet seal 86 in a seal recess 87
therebetween. The outer diameter of the poppet face 85 is
smaller than the outer diameter of the seal-retention web 89 so
as to allow, during assembly of the valve cartridge 14, the
poppet seal 86 to be slipped over the poppet face 85 and into
the seal recess 87. Additionally, the outer diameter of the
poppet face 85 being smaller than the diameter of the second
valve seat 50, and the outer diameter of the seal retention web
89 being greater than the diameter of the second valve seat 50
allows the poppet seal 86 to contact the second valve seat 50,
and also allows the seal-retention web 89 to support the poppet
seal 86 against the second valve seat 50.
The flow-direction flange 88 of the second poppet.80
has compression notches 93 spaced circumferentially therearound
which accommodate support spokes 98 of the second poppet
support 35, when the second valve 160 is in its open position,
thereby reducing the necessary overall length of the valve
cartridge 14.
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The second poppet support 105, as seen in detail in
Figures 6A and 6B, broadly consists of a guide sleeve 96,
support spokes 98, and a support rim 100.
The guide sleeve 96 defines a longitudinal bore 95
therethrough which receives the poppet stem 90 of the second
poppet 80 during assembly of the valve cartridge 14. The guide
sleeve 96 guides reciprocal axial movement of the second poppet
80 relative to the second poppet support 105. The guide sleeve
bore 95 is sized so as to accommodate the poppet stem 90 of the
second poppet 80 and the small splines 91 thereon. The
longitudinal bore 95 of the guide sleeve 96 also has defined
therein four longitudinal alignment slots 99, circumferentially
spaced so as to accommodate the four large splines 92 of the
second poppet poppet stem 90. When the poppet stem 90 is
inserted into the bore 95 of the guide sleeve 96, the large
splines 92 co-operate with the alignment slots 99 to prevent
relative rotation between the second poppet 80 and the second
poppet support 105. Further, the small splines 91 of the
poppet stem 90 provide a reduced contact area between the
poppet stem 90 and the guide sleeve 96 of the second poppet
support 105, reducing friction during axial movement of the
second poppet 80.
Extending radially outwardly from a downstream end of
the guide sleeve 96 of the second poppet support 105 is a
spring support web 96a, and extending upstream from a periphery
of the spring support web 96a is a spring retention flange 96b.
When the valve cartridge 14 is assembled, the second spring 180
is compressed between the downstream surface of the poppet face
85 of the second poppet 80 and the spring support web 96a of
the second poppet support 105. The second spring 180 is held
in place by the stem 90 and the spring-retention flange 81 of
the second poppet 80 at one end, and the guide sleeve 96 and
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the spring retention flange 96b of the second poppet support
105 at the other.
Support spokes 98 extend radially outwardly and
upstream from the spring retention flange 96b of the second
poppet support 105 and connect the guide sleeve 96 with the
support rim 100. The support spokes 98 further ensure that the
guide sleeve 96 is positioned and maintained centrally within
the support rim 100, and that the longitudinal bore 95 through
the guide sleeve 96 is coaxial with the remainder of the valve
cartridge 14. The support spokes 98 are spaced
circumferentially so as to engage the compression notches 93 of
the flow-direction flange 88 of the second poppet 80 to
maximize the amount of compression of the second spring 180
when the second valve 160 is in its open position. Spaces
between the support spokes 98 define flow passages 97 through
the second poppet support 105.
An exterior surface of an upstream portion of the
support rim 100 of the second poppet support 105 has an annular
connecting groove 107 defined therein. This connecting groove
107 is adapted to accept in locking relationship, the inwardly-
projecting connection ridge 43 of the downstream connection
flange 55b of the first poppet support 35. Spaced
circumferentially within this connecting groove 107 are four
alignment tabs 108. This connecting groove 107 and these
alignment tabs 108 function to connect the second poppet
support 105 to the first poppet support 35, to align it
therewith, and to resist separation and relative rotation
therebetween once locked together.
When the valve cartridge 14 is in its assembled form,
the support spokes 98 of the second poppet support 105 form a
flat downstream surface 115 at the downstream end 190 of the
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cartridge 14 that is capable of co-operating with a cartridge-
retaining face 141 on a retaining cage 130, as discussed in
greater detail below.
Further, the support spokes 98 of the second poppet
support 105 have an outer diameter that is larger than the
outer diameter of other valve components of the valve cartridge
14 such that when the valve cartridge 14 is assembled, the
downstream end 190 of the valve cartridge 14 has an outer
diameter greater than that of the remainder of the valve
cartridge 14 to facilitate proper insertion and removal of the
valve cartridge 14 from the valve body 16 as described in
greater detail below.
The first valve seat alignment tabs 21, the second
poppet support alignment tabs 108, and the connecting groove
notches 44, 45 of the upstream and downstream connection
flanges 55a, 55b of the first poppet support 35 are
circumferentially positioned such that when the valve cartridge
14 is assembled, the support spokes 38, 98 of the first and
second poppet supports 35, 105 align so as to maximize flow
through the valve cartridge 14 when the first and second valves
150, 160 are in their open positions.
An exemplary manner in which the preferred embodiment
valve cartridge 14 may be assembled will now be described.
First, the various seals are inserted into their
respective seats. The poppet seal 26 of the first poppet 24 is
pushed over the poppet face 25 and into the seal recess 27 of
the first poppet. Next, the poppet seal 86 of the second
poppet 80 is pushed over the poppet face 85 and into the seal
recess 87 of the second poppet 80. The first valve seat 0-ring
195 is then pushed onto the first valve seat 18 to seat within
the first valve seat 0-ring groove 20 thereon, and the first
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poppet support 0-ring 57 is pushed onto the first poppet
support 35 to seat within the first poppet support 0-ring
groove 56 thereon.
Next, the first valve 150 is assembled. The first
spring 175 is placed over the guide sleeve 36 of the first
poppet support 35 and the poppet stem 30 of the first poppet 24
is inserted into an upstream end of the guide sleeve 36. The
first valve seat 18 is placed over the first poppet 24 and
pushed towards the first poppet support 35 causing the first
spring 175 to compress. Once the first valve seat 18 contacts
the first poppet support 35, these two components are twisted
relative to one another until the first valve seat alignment
tabs 21 of the first valve seat 18 align with the connecting
groove notches 44 of the upstream connection flange 55a of the
first poppet support 35. Further compression between the two
components allows the connection ridge 42 of the upstream
connection flange 55a to engage the first valve seat connecting
groove 23. Once engaged, the interaction between the
connection ridge 42 of the upstream connection flange 55a of
the first poppet support 35 and the connecting groove 23 of the
first valve seat 18 resists separation of the two valve
components, while interaction between the first valve seat
alignment tabs 21 and the upstream connecting groove notches 44
of the first poppet support 35 prevents relative rotation
between the two valve components during operation.
The second valve 160 is then assembled. The second
spring 180 is placed over the second poppet support guide
sleeve 96 and the stem 90 of the second poppet 80 is inserted
into the second poppet support guide sleeve 96. A downstream
side of the first poppet support 35 is placed over the second
poppet 80 and pushed towards the second poppet support 105
causing the second spring 180 to compress. Once the first
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poppet support 35 contacts the second poppet support 105, these
two components are twisted relative to one another until the
second poppet support alignment tabs 108 of the second poppet
support 105 align with the connecting groove notches 45 of the
downstream connection flange 55b of the first poppet support
35. Further compression between the two components allows the
connection ridge 43 of the downstream connection flange 55b to
engage the second poppet support connecting groove 107. Once
engaged, the interaction between the connection ridge 43 of the
second poppet support 105 and the connecting groove 107 of the
second poppet support 105 resists separation of the two valve
components, while interaction between the second poppet support
alignment tabs 108 and the connecting groove notches 45 of the
first poppet support 35 prevents relative rotation between the
two valve components during operation.
Although an exemplary manner of assembling the valve
cartridge 14 has been described, it is to be understood that
the cartridge may be assembled using other methods and in other
sequences, as will be understood by those skilled in the art.
Once assembled, the valve cartridge 14 is self-
contained insofar as the valve cartridge 14 is a single unit
containing all components necessary for the valve cartridge 14
to function as a valve when placed in a valve body, and wherein
all of these components are either integral with, attached to,
contained within one another, or are otherwise connected such
that the cartridge remains unitary during handling. Further,
the major components of the valve cartridge 14 resist relative
rotation by the means described above to avoid causing unwanted
wear and/or flow turbulence.
The operation of the preferred embodiment valve
cartridge 14 will now be described. Figures 7A and 7B
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illustrate, respectively, the closed and open positions for the
fully assembled valve cartridge 14.
When the valve cartridge 14 is installed in a valve
body and the pressure difference between the upstream and
downstream ends 185, 190 of the valve cartridge 14 is small or
is zero, the first and second valves 150, 160 are closed as
shown in Figure 7A. The first spring 175 pushes the first
poppet 24 upstream such that the seal 26 of the first poppet 24
is pressed against the first valve seat surface 22. Similarly,
the second spring 180 pushes the second poppet 80 upstream such
that the seal 86 of the second poppet 80 is pressed against the
second valve seat 50. In this state, two independent seals are
created to restrict flow through the valve cartridge 14. The
upstream seal is formed by the first poppet poppet face 25, the
first poppet poppet seal 26, the first valve seat surface 22,
the first valve seat 18 and the first valve seat 0-ring 195.
The downstream seal is formed by the second poppet poppet face
85, the second poppet poppet seal 86, the second valve seat 50,
the first poppet support 35, and the first poppet support 0-
ring 57.
If the water pressure at the downstream end 190 of
the valve cartridge 14 exceeds the pressure at the upstream end
185, this pressure differential tends to increase the force
with which the second poppet 80 is pressed against the second
valve seat 50, thereby improving the seal between the second
poppet poppet seal 86 and the second valve seat 50. In such
circumstances, the second valve 160 will be closed and no
additional pressure is exerted on the downstream surface of the
first valve 150, though the first valve 150 will remain closed
due to the force exerted by the first spring 175 on the first
poppet 24, as explained above.
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Should the second valve 160 fail, the first valve 150
will still restrict backflow (flow from the downstream end 190
to the upstream end 185) of water through the cartridge.
Indeed, if the second valve 160 fails when the water pressure
at the downstream end 190 of the valve cartridge 14 exceeds the
pressure at the upstream end 185, the force with which the
first poppet 24 is pressed against the first valve seat surface
22 in increased, thereby improving the seal between the first
poppet poppet seal 26 and the first valve seat surface 22.
As can be seen, so long as at least one of the first
and second valves 150, 160 do not fail, backflow through the
valve cartridge 14 will be restricted. Accordingly, the two
valves 150, 160 provide the valve cartridge 14 with its dual-
check feature. The valves provide redundant protection, such
that if one of the valves fails, backflow through the valve
cartridge 14 will still be checked.
If the water pressure at the upstream end 185 of the
valve cartridge 14 exceeds the pressure at the downstream end
190 by a degree sufficient to overcome the spring force exerted
by the first and second springs 175, 180, then the pressure
against the poppet faces 25, 85 moves the first and second
poppets 24, 80 downstream away from the first and second valve
seats 22, 50 respectively, opening both valves as shown in
Figure 7B and allowing water to flow from the upstream end 185
of the valve cartridge 14 to the downstream end 190. When both
valves 150, 160 are open, water from the upstream end 185 of
the valve cartridge 14 is directed to the periphery of the
first poppet poppet face 25, flows in an annular passage
between the periphery of the first poppet 24 and the interior
surface of the connection sleeve 18b of the first valve seat
18, through the gaps between the support spokes 38 of the first
poppet support 35, around the periphery of the second poppet 80
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and past the gaps between the support spokes 98 of the second
poppet support 105.
Having described the features of the preferred
embodiment valve cartridge 14, its assembly as well as its
operation, an exemplary valve application incorporating the
valve cartridge 14 will now be described. In this case, the
valve application is the preferred embodiment check valve 200
of a second aspect of the present invention, illustrated in
Figures 8 and 11.
Figure 8 shows an exploded view of the major elements
of the preferred embodiment check valve 200. As noted
previously, the very specific exemplary context described for
the check valve 200 is one used to permit flow from a
horizontal pipe connected to a municipal water supply down to a
vertical pipe connected to a building water system, but not
vice versa. The major elements of the check valve 200 are the
valve body 16, valve cartridge 14, retaining cage 130 and
service cap 17.
The valve body 16, shown in detail in Figure 9, has a
vertical main body bore 202, a horizontal inlet bore 204
communicating with the main body bore 202 from the side, and a
vertical outlet bore 206 extending down from the main body bore
202.
The inlet bore 204 is sized to accommodate the valve
cartridge 14 in a close fit and has a lip 207 near its outside
end to retain the valve cartridge 14 within the inlet bore 204.
An outside surface 208 of the valve body 16 adjacent the inlet
bore 204 is provided with suitable attachment features to allow
the sealed connection of the horizontal pipe connected to the
municipal water supply. As illustrated in Figure 8, the
attachment features of the check valve 200 are of the meter
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flange type. Of course, other attachment features may be used,
female iron pipe for example.
The outlet bore 206 is sized to accommodate the
vertical pipe connected to the building water system. In the
illustrated valve body 16, a lower end of the outlet bore 206
is provided with internal threading 210 as shown in Figure 11
to facilitate a sealed connection with the vertical pipe. Of
course, other attachment means may be implemented.
The main body bore 202 is sized to accommodate the
insertion of the valve cartridge 14 therein, manipulation of
the valve cartridge 14 such that it can be inserted into the
inlet bore 204, as well as insertion of the retaining cage 130.
An upper end of the main body bore 202 is provided with
internal threading 212 to engage external threading 214 of the
service cap 17. In conjunction with a service cap 0-ring 216,
the service cap 17 seals the upper end of the main body bore
202.
The retaining cage 130 has an open-lattice structure
consisting of struts, spokes, rings, and partial rings that
provide structural support for a substantially flat cartridge-
retaining face 141 adapted to retain the valve cartridge 14
within the inlet bore 204 once the check valve 200 is
assembled, while allowing water to easily flow through the
retaining cage 130. The cartridge-retaining face 141 has at
its center, a ring 142 adapted to permit the second poppet
poppet stem 90 of the preferred embodiment valve cartridge 14
to extend therethrough when the second valve 160 of the valve
cartridge 14 is in its open position. The retaining cage 130
further has a tab 135 at its top to facilitate insertion,
rotation and extraction of the retaining cage 130 from the
valve body 16.
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To assemble the check valve 200, the valve cartridge
14 is first inserted into the main body bore 202 through the
top and slid into the inlet bore 204 upstream-end 185 first.
As explained above, the second poppet support support spokes 98
have an outer diameter that is larger than the remainder of the
valve cartridge 14, and indeed larger than the internal
diameter of the inlet bore 204. As a result of this feature,
the valve cartridge 14 can only be inserted into the inlet bore
204 upstream end 185 first, namely in the correct orientation.
Following insertion of the valve cartridge 14, the
retaining cage 130 is slid into the main body bore 202. To
facilitate this task, the tab 135 may be grasped and the
retaining cage 130 rotated about its longitudinal axis such
that cartridge-retaining face 141 is oriented towards the inlet
bore 204, before the retaining cage 130 is lowered into the
main body bore 202. As the retaining cage 130 is substantially
round in horizontal cross-section with the exception of the
substantially flat cartridge-retaining face 141, the retaining
cage 130 can only be inserted into the main body bore 202 in
its correct orientation, namely with the cartridge-retaining
face 141 abutting the downstream end 190 of the valve cartridge
14 and retaining it in place within the inlet bore 204.
With the retaining cage 130 in place, the service cap
17 is screwed onto the top of the main body bore 202 with the
service cap 0-ring 216 therebetween to seal the top of the main
body bore 202.
In use, the check valve 200 is screwed onto the
vertical pipe connected to the building water system such that
the internal threading of the outlet bore 206 engages external
threading on the vertical pipe. The horizontal pipe is then
fluidly connected to the inlet bore 204 using the above-
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mentioned attachment features. Connected in this manner, the
valve cartridge 14 which is retained in place by the retaining
cage 130, allows water to flow from the horizontal pipe to the
vertical pipe, but not vice versa.
To service the check valve 200, the service cap 17 is
removed, and the retaining cage 130 extracted using the tab
135. The valve cartridge 14 is then removed through the main
body bore 202 and inspected, serviced or replaced as necessary.
Notably, the valve body 16 need not be disconnected from either
the horizontal or vertical pipe for this procedure. The check
valve 200 may then be reassembled as described above.
In the above description, the valve cartridge of the
present invention has been described in the context of a very
specific application, namely its use in an elbow-style check
valve in allowing flow from a horizontal pipe connected to a
municipal water supply to a vertical pipe connected to a
building watery system but not vice versa. It is to be
understood that the valve cartridge of the present invention
can be used in a wide variety of applications as will be
understood by those skilled in the art. For example, the valve
cartridge 14 can be used in many plumbing or waterworks
application to ensure unidirectional flow through a conduit.
It can also be used to ensure unidirectional flow of other
fluids, sewage or gasses for example. Additionally, its use is
of course, not limited to insertion within the preferred
embodiment elbow-style check valve of the present invention,
but could be used in other elbow valves, in straight-pipe
valves, etc..
The check valve of a second aspect of the present
invention has also been described in a very specific
application, namely its use in allowing flow from a horizontal
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pipe connected to a municipal water supply to a vertical pipe
connected to a building watery system but not vice versa.
However, the check valve can of course be used in a variety of
other applications, in chemical production plant applications,
plumbing applications, etc..
While both the valve cartridge and the check valve
can be used in retrofit applications, they can also be used in
new installations.
Very specific geometries, orientations,
configurations and relative positions of the various elements
have also been provided for both the valve cartridge and check
valve. However, it is to be understood that other suitable
geometries, orientations, configurations and relative positions
may be used by persons skilled in the art without necessarily
departing from the scope of the invention. For example, the
components of the valve cartridge need not necessarily be round
in cross-section - a square valve cartridge for use within a
square valve body or conduit is also contemplated. As another
example, although the preferred embodiment valve cartridge has
been provided with four sets of alignment tabs and notches to
align the first valve seat, the first poppet support and the
second poppet support, a greater or lesser number of such tabs
and notches may be used, 3 or 6 for example. A similar comment
applies in respect of, for example, the number of spokes for
each of the first and second poppet supports and the
corresponding number of compression notches on each of the
first and second poppet flow-direction flanges, the number of
large splines on the first and second poppet stems and
corresponding number of alignment slots in the first and second
poppet guide sleeves, the number of small splines on the first
and second poppet stems, etc.
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The poppet stems of the valve cartridge have been
described as having small splines thereon to reduce the contact
surface between the poppet stems and the poppet guides.
However, the present invention also contemplates the absence of
such splines.
In the preferred embodiment valve cartridge and check
valve, the valve body and the service cap are made of brass
alloy, the various seals and 0-rings are made of rubber, the
springs are made of steel, and the remaining valve components
are made of plastic. However, it is to be understood that
other suitable materials may be used without necessarily
departing from the scope of the invention, as will be
appreciated by persons skilled in the art.
While the check valve has been described and
illustrated as used with the preferred embodiment valve
cartridge, it is to be understood that the check valve can also
be used with other valve cartridges, a single-check valve
cartridge for example.
Although the check valve of the present invention has
been described as an elbow-style check valve, it is to be
understood that the check valve need not be elbow-style. For
example, the check valve may be a straight valve where the
outlet bore would be colinear with the inlet bore.
While the interior features of the check valve of the
present invention have been described as being bores, it is to
be understood that these features need not necessarily be
cylindrical. These features could for example be cuboid.
Numerous modifications and variations of the present
invention are possible in light of the above teachings. It is
therefore to be understood that within the scope of the
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appended claims, the invention may be practised otherwise than
as specifically described herein.
