Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROUND OF TH~ INVENTION
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1~ Field of the Invention
Th i5 inven-tion relates to check valve
inserts for use with conventional plumbing "T" type
couplings to make ball-type check valves which are
~ particularly adapted for use in manholes that drain
- into storm sewers or ditches.
2. Description of_the Prior Art
A common check valve design utilizes a "T"
shaped casing having a vertically oriented inlet port
through which fluid may pass vertically to exit via a
laterally extending outlet port. Such designs
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` commonly employ a valve seat in the inlet port and a
ball closure member or "check ball" which is moveable
`~ 15 in a substantially vertical direction. To prevent
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loss of the check ball through the outlet port, some
devices provide enlarged cavities between the inlet
and outlet ports to permit the use of a check ball
having a diameter greater than that of the outlet
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port. However, casings for such devices generally
need to be custom manufactured which renders
; fabrication relatively complicated and expensive.
U.S. Patent No. 3,648,729 issued 14 March
1972 to John W. Balkany shows a valve insert assembly
for converting an ordinary pipeline "T" coupling into
a ball type check valve which thus obviates the need
for fabrication of a special casing. The Balkany
insert includes a spring which surrounds the check
ball to constrain it to movement in a substantially
vertical direction.
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Another method for preven-ting loss of the
check ball through the outlet port is shown in U.S.
Patent No. 2,278,715 issued 7 April, 1942 to Ludwig T.
Stoyke et al, which discloses use of an apertured
guide sleeve to surround the check ball and constrain
it to movement in a substantially vertical direction.
The spring (in the Balkany device) and the
sleeve (in the Stoyke device) serves to yuide the
~- check ball to and from the valve seat.
Although either of the Balkany or Stoyke
devices may be used in conventional pipeline "T"
couplings, they are susceptible to accumulation around
the valve seat area of solid material which may be
present in the fluid passing through the valve. Such ~ ;
accumulations may eventually result in fluid leakage
; past the check ball when the ball is in the "closed"
or seated position. Furthermore, the Stoyke device is
said to operate most satisfactorily when the clearance
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- between the check ball and the guide sleeve is less
- 20 than a specific amount. At some point, a minimum
` clearance between the check ball and the guide sleeve
~` will be reached below which accumulations of solid
material may inhibit free movement of the check ball
within the guide sleeve eventually resulting in
leakage past the check ball. Both the Balkany and
Stoyke devices must be disassembled to provide access
to the valve seat area for removal of accumulated
deposits therefrom. This problem is exacerbated where
the device is to be installed, for example to control
drainage from a manhole into a sewer or ditch, because ;
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relatively substantial amounts of solid foreign matter
may enter the valve assembly.
Summary of the Invention
The invention is directed to a check valve
insert for installation between the inle-t and outlet
ports of a fluid conduit. The ~luid conduit outlet
~ port communicates with a drainage conduit. The insert
- comprises an apertured coupler for insertion into the
inlet port of the conduit. The coupler includes a
valve seat around the aperture. The insert also com-
prises a cylindrically apertured guide sleeve fixed to
~- the coupler to project into the condui-t above the
valve seat and permit fluid communication from the
inlet port through the coupler aperture and through
the sleeve aperture to the outlet port. The insert
further comprises a ball closure member positioned
within the sleeve for sealing engagement against the
-~ valve seat to prevent 1uid communication from the
outlet port to the inlet port.
Preferably, the sleeve includes a plurality
of apertures spaced around the upper end of the
sleeve.
Preferably, the ball closure member is sized
to permit passage of solid particulate matter oE a
;~ 25 predetermined size between the ball closure member and
the interior walls of the sleeve.
Advantageously, the sleeve is fixed to the
:! coupler to provide a smooth transition between the
sleeve and the valve seat.
- 30 Preferably, when the insert is installed in
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the conduit, the plurality of sleeve apertures are
positioned above the lowest point of entry from the
conduit outlet port to the drainage conduit.
Advantageously, the sleeve is sized to
` 5 permit insertion of a drain cleaning tool past the
sleeve and into the conduit when the insert is
installed in the conduit.
~- PreEerably, the ball closure member is form-
ed of material having a density which is greater than
. 10 that of water and which is such that fluid rising
around the conduit to about the lowest point of entry
from the conduit outlet port to the drainage conduit
lifts the ball closure member above the valve seat.
Brief Description of the D_awing
-~ 15 The figure is a cross-sectional side eleva~
tion view of one embodiment of the check valve insert - `
.~; which is shown installed in a conventional plumbing
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"T" fitting.
. Description of An Embodiment of the Invention
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`. 20 A conventional hollow plumbing pipleine "T"-
. shaped fitting or "conduit" 10 has vertically opposed ~.
. upper and lower ends 12 and 14 respectively. Lower
.~ end 14 is left open to serve as an inlet port through :~.
which fluid may pass vertically to enter leg 16 which
. 25 projects from the side of conduit 10 to serve as an
outlet port. Leg 16 is connected to a drainage
conduit such as drain pipe 18 which leads to a storm
sewer or ditch. A threaded adaptor 20 is fixed in
upper end 12 to removably receive threa~ed plug 22
which prevents fluid passage through upper end 12.
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Plug 22 may be removed to facilitate cleaning as
hereinafter described.
r~e check valve insert comprises cylindri-
cally apertured guide sleeve 24, coupler 26 and ball
closure member or "check ball" 28. Coupler 26 i8
sized to fit snugly in conduil: lower end 14. In cases
where the e~ternal diameter of coupler 26 i.s too small
to permit it to be snugly fitted within lower end 14
-- it will be necessary to include pipe increase coupler
30 to support coupler 26 in conduit lower end 14.
Coupler 26 is apertured to permit fluid to pass from
the inlet port through coupler 26. An inverted
semi-conical valve seat 32 is provided around the
- coupler aperture. Check ball 28 is sized to permit
~- 15 sealing engagement with valve seat 32 whereby fluid
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` flow from the conduit outlet port to its inlet port is
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prevented.
-~ Guide sleeve 24 is rigidly affixed to cou-
pler 26 to project into conduit 10 above valve seat 32
and to permit fluid communication from the conduit
inlet port through the coupler and sleeve apertures to
~- the conduit outlet port. Guide sleeve 24 also serves
as a vertical channel within which check balL 28 is
constrained to travel. The length of guide sleeve 24
is selected to leave a passageway 34 between the inner
surface of conduit 10 and the uppermost rim of sleeve
24 through which a drain cleaning tool may be passed
as hereinafter described.
A plurality o:E apertures 36 are spaced
around the upper end of sleeve 24 such that when the
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insert is installecl in condult 10, the apertures are
just above the lowest point of entry from the conduit
outlet port into drain pipe 18. Apertures 36 are
sized to prevent passage therethrough o relatively
large solid particles which may wash back into conduit
10 from drain pipe 18 if fluid levels in adjacent
storm sewers are abnormally high. (In such cases,
check ball 28 will prevent fluid passage from drain
pipe 18 through the conduit inlet port). However,
apertures 36 should not be made so small that they
inhibit the free flow of fluid therethrough. In
practice, the combined cross-sectional area for all of !
the apertures 36 should be about equal to the
cross-sectional area of the aperture in coupler 26.
;~ 15 rrhe recessed annular region 38 surrounding
the lower end of sleeve 24 serves as a receptical to
trap particulate foreign matter which may wash back
into coupling 10 from drain pipe 18.
Check ball 28 should be made of a material
having a density which is greater than that of water,
- but which is sufficiently low to permit fluid pressure
(the fluid is typically water) to lift the check ball
free of valve seat 32 when fluid levels outside con-
- duit 10 rise to about the lowest point of e~ntry from
conduit 10 into the conduit outlet port. The diameter
of check ball 28 should be selected with reference to
the inside diameter of sleeve 24 to permit solid
particulate matter of a predetermined size to pass
between the check ball and the sleeve without inhibit-
ing free movement of the check ball within the sleeve
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and without restricting the free flow of fluid through
sleeve 24. For example, in applications where -the
check valve insert is to be installed in a conduit
: which is near the bottom of a manhole housing electri-
cal cables, there should be sufficient clearance
~ between check ball 28 and sleeve 24 to permit passage
~ of particulate matter such as stripped wire ends which
may be carried into the conduit with fluids which
accumulate in the manhole.
The positioning of apertures 36 relative to
the point of entry from conduit 10 into the conduit
outlet port; the total area of aperkures 36 relative
~: to the area of the aperture in coupler 26; the density
of check ball 28 and i-ts size relative to sleeve 24
are all selected to ensure that the valve will open to
- drain fluid surrounding conduit 10 into drain pipe 18 -:
~`~; when fluid surrounding conduit 10 rises to about the
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lowest point of entry from the conduit outlet port
into drain pipe 18. It has been found that a one and
one-half inch diameter rubber lacrosse ball (available
. at sporting goods stores) serves as a satisfactory
check ball for use in conventional 4" diameter pipe
systems.
It is important to eliminate within the
check valve insert, as far as practically poæsible,
: crevices and interstices which may trap foreign par-
ticulate matter leading to build-ups which may eventu-
ally inhibit the free movement of check ball 28 in
:. sleeve 24 or prevent adequate sealing of check ball 28
against valve seat 32. To this end, sleeve 24 and
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coupler 26 are formed to provide a ~mooth -transition
arouncl the rim of valve seat 32 where it contacts
sleeve 24. In addition, the interior surEace of
sleeve 24 is made smooth to inhibit accumulations of
foreign material in sleeve 24 which might interfere
with free movemen-t of check ball 28 in sleeve 24.
In operation, the check valve insert is
installed as shown in conduit 10. Conduit 10 may, for
example, be located near the bottom of a manhole. As
fluid levels rise in the manhole with respect to
check ball 28 (for example, due to rains or drainage
into the manhole) fluid will enter the conduit inlet
port and check ball 28 will eventually be lifted free
of valve seat 32 enabling fluid to pass up through
`` 15 the aperture in coupler 26 and into sleeve 24. The
fluid may continue to rise in sleeve 24 to the level
of apertures 36 at which point the fluid will pass
through apertures 36 ana into annular region 38 which
~-- will quickly be filled. Once region 38 is filled,
fluid may exit conduit 10 through leg 16 and drain
pipe 18 to a storm sewer or ditch.
Particulate foreign matter present in the
manhole such as stripped wire ends, dirt, etc. may be
carried by rising fluid levels into sleeve 24 and
pass through apertures 36 to accumulate in annular
region 38. Also, over time, particulate foreign
matter may accumulate in annular region 38 due to
fluid backflows from drain pipe 18. In either case,
it will be desirable to remove threaded plug 22 at
periodic intervals and use a drain cleaning tool to
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remove the accumulated foreign matter from annular
; region 38. After threaded plug 22 has been removed
from adaptor 20, the drain cleaning tool may be
: inserted through conduit uppe:r end 12 and passageway
34 into annular region 38. In like manner, the drain
cleaning tool may be passed through conduit upper end
: 12 and passageway 34 into drain pipe 18 to clear
: blockages from the drain pipe.
To avoid corrosion in salt water environ-
ments encountered in low lying tidal areas, the
components of the check valve insert may be made from
~- suitable materials such as plastic.
Obvious variations in detail, construction
and scale may be made without departing from the scope
of the invention as defined in the appended claims.
~ In the description and claims, words such as "upper"
: and "lower" are to be taken in a relative rather than ~:~
- and absolute senseO
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