U.S. patent number RE39,721 [Application Number 10/717,425] was granted by the patent office on 2007-07-10 for discharge outlet for double wall containment tank assembly.
This patent grant is currently assigned to Snyder Industries, Inc.. Invention is credited to Darwin Garton.
United States Patent |
RE39,721 |
Garton |
July 10, 2007 |
Discharge outlet for double wall containment tank assembly
Abstract
A discharge outlet is provided for attachment to a double wall
containment tank assembly having an inner tank and an outer
containment vessel. The discharge outlet includes a conduit
fluidically connected to the fluid receiving chamber of the inner
tank and extending exteriorly of the outer containment vessel, a
flexible annular sealing member positioned between the inner tank
and the outer containment vessel, and couplers for attaching the
sealing member to the inner tank and the outer vessel in
surrounding relationship to the conduit. The containment area
between the two tanks which is designed fro containing spills from
the inner tank is thereby fluidically isolated form the access
opening through which the conduit passes.
Inventors: |
Garton; Darwin (Lincoln,
NE) |
Assignee: |
Snyder Industries, Inc.
(Lincoln, NE)
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Family
ID: |
24067822 |
Appl.
No.: |
10/717,425 |
Filed: |
November 19, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
09519326 |
Mar 6, 2000 |
06318581 |
Nov 20, 2001 |
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Current U.S.
Class: |
220/565;
220/4.12; 220/661 |
Current CPC
Class: |
B65D
90/24 (20130101); B67D 7/0288 (20130101) |
Current International
Class: |
B65D
90/02 (20060101) |
Field of
Search: |
;220/661,567.2,4.12,567.3,565 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Castellano; Stephen
Attorney, Agent or Firm: Hovey Williams LLP
Claims
What is claimed is:
1. A discharge outlet for a double walled containment tank having
an inner tank having a chamber for receiving liquid therein and a
port for the passage of liquid therethrough, and an outer
containment vessel having an access opening aligned with the port,
the inner tank and the outer containment vessel defining a
containment area therebetween, said discharge outlet comprising: a
conduit fluidically coupled to the inner tank; a flexible, annular
sealing member positioned between the inner tank and the outer
containment vessel in substantial alignment with the port and the
access opening in surrounding relationship to said conduit.Iadd.,
said sealing member presenting a pair of opposed holes, one of said
holes being of substantially greater diameter than the other of
said holes.Iaddend.; a first coupler for connecting said sealing
member to the inner tank around the port; and a second coupler for
connecting said sealing member to the outer containment vessel
around the access opening and thereby fluidically isolating the
containment area from the access opening.
2. A discharge outlet as set forth in claim 1, wherein said sealing
member includes a circumferentially extending cup-shaped
protrusion.
3. A discharge outlet as set forth in claim 2, wherein said sealing
member is a flexible synthetic resin material.
4. A discharge outlet as set forth in claim 3, wherein said sealing
member includes a substantially flat inner wall extending radially
inwardly from said protrusion and having .[.a central.]. .Iadd.said
smaller diameter .Iaddend.hole therein for permitting the passage
of liquid therethrough.
5. A discharge outlet as set forth in claim 4, wherein said first
coupler includes an inner flange positioned in the chamber and an
outer flange positioned in the containment area for receiving a
wall of the inner tank therebetween, each of said inner flange and
.[.intermediate.]. .Iadd.outer .Iaddend.flange.Iadd.s
.Iaddend.having a central opening for the passage of liquid
therethrough.
6. A discharge outlet as set forth in claim 5, wherein said conduit
includes a discharge tube fluidically connected to said
intermediate flange and having a length sufficient to extend
exteriorly of the outer vessel.
7. A discharge outlet as set forth in claim 6, wherein said conduit
includes an inner tube fluidically connected to said inner
flange.
8. A discharge outlet as set forth in claim 3, wherein said sealing
member includes a substantially flat outer wall extending radially
inwardly from said protrusion and having an inner margin.
9. A discharge outlet as set forth in claim 8, wherein said inner
margin is spaced outwardly from said conduit.
10. A discharge outlet as set forth in claim 3, wherein said second
coupler includes an inner flange plate .[.positioned in said
channel.]. .
11. A discharge outlet as set forth in claim 10, wherein said inner
flange is provided as two semi-annular flange plate halves.
12. A discharge outlet as set forth in claim 11, wherein said
second coupler includes an outer flange plate .[.and positioned
relatively exteriorly of said flat outer wall.]. .
13. A double walled containment tank assembly comprising: an inner
tank having a chamber for receiving liquid therein and a port for
the passage of liquid therethrough; an outer containment vessel
having an access opening aligned with the port, the inner tank and
the outer containment vessel defining a containment area
therebetween; and a discharge outlet, said discharge outlet
including: a conduit fluidically coupled to said inner tank; a
flexible, annular sealing member positioned between said inner tank
and said outer containment vessel in substantial alignment with
said port and said access opening in surrounding relationship to
said conduit.Iadd., said sealing member presenting a pair of
opposed holes, one of said holes being of substantially greater
diameter than the other of said holes.Iaddend.; a first coupler for
connecting said sealing member to said inner tank around said port;
and a second coupler for connecting said sealing member to said
outer containment vessel around said access opening and thereby
fluidically isolating said containment area from said access
opening.
14. A containment tank as set forth in claim 13, wherein said
sealing member includes a circumferentially extending cup-shaped
protrusion.
15. A containment tank as set forth in claim 14, wherein said
sealing member is a flexible synthetic resin material.
16. A containment tank as set forth in claim 15, wherein said
sealing member includes a substantially flat inner wall extending
radially inwardly from said protrusion and having .[.a central.].
.Iadd.said smaller diameter .Iaddend.hole therein for permitting
the passage of liquid therethrough.
17. A containment tank as set forth in claim 16, wherein said first
coupler includes an inner flange positioned in said chamber and an
outer flange positioned in the containment area for receiving a
wall of said inner tank therebetween, each of said inner flange and
.[.intermediate.]. .Iadd.outer .Iaddend.flange.Iadd.s
.Iaddend.having a central opening for the passage of liquid
therethrough.
18. A containment tank as set forth in claim 17, wherein said
conduit includes a discharge tube fluidically connected to said
intermediate flange and having a length sufficient to extend
exteriorly of said outer vessel.
19. A containment tank as set forth in claim 18, wherein said
conduit includes an inner tube fluidically connected to said inner
flange and extending into said chamber adjacent a bottom wall of
said inner tank.
20. A containment tank as set forth in claim 15, wherein said
sealing member includes a substantially flat outer wall extending
radially inwardly from said protrusion and having an inner margin,
said outer wall being positioned proximate said outer vessel.
21. A containment tank as set forth in claim 20, wherein said inner
margin is spaced outwardly from said conduit.
22. A containment tank as set forth in claim 15, wherein said
second coupler includes an inner flange plate .[.positioned in said
channel.]. .
23. A containment tank as set forth in claim 22, wherein said inner
flange is provided as two semi-annular flange plate halves.
24. A containment tank as set forth in claim 23, wherein said
second coupler includes an outer flange plate .[.and positioned
relatively exteriorly of said flat outer wall and proximate said
outer vessel.]. .
.Iadd.25. A discharge outlet for a double walled containment tank
having an inner tank provided with a chamber for receiving liquid
therein and having a side wall provided with a port therein for
passage of liquid therethrough, and an outer containment vessel
having a wall portion provided with an access opening having a
predetermined area and positioned generally across from the port in
the side wall of the inner tank, the inner tank and the outer
containment vessel defining a containment area therebetween, said
discharge outlet comprising: a conduit coupled to the port in the
side wall of the inner tank for fluidic communication of the
conduit with the inner tank; said conduit extending through the
access opening in the outer containment vessel; a flexible annular
boot member positioned in surrounding relationship to the conduit
and having opposed annular end portions, each of said annular end
portions defining a hole, one of said holes having a diameter
greater than the diameter of the other of said holes; a first
coupler sealingly coupling the end portion of the boot member
having said larger diameter hole to the outer containment vessel
around the access opening therein; and a second coupler sealingly
coupling the end portion of the boot member having said smaller
diameter hole adjacent to the conduit in spaced relationship from
the first coupler, the area of said access opening being greater
than the cross-sectional area of that part of the conduit extending
through said access opening, whereby said boot member prevents
leakage of liquid from the double walled containment tank that may
collect in the containment area..Iaddend.
.Iadd.26. A discharge outlet as set forth in claim 25, wherein the
boot member is sufficiently flexible to permit limited relative
movement between the inner tank and the outer containment
vessel..Iaddend.
.Iadd.27. A discharge outlet as set forth in claim 25, wherein said
first coupler is annular and spaced radially outwardly of said
conduit to permit limited relative movement between the conduit and
the containment vessel..Iaddend.
.Iadd.28. A discharge outlet as set forth in claim 25, wherein said
other opposed annular end portion of the boot member is sealingly
coupled to the conduit adjacent the port in the side wall of the
inner tank..Iaddend.
.Iadd.29. A discharge outlet as set forth in claim 25, wherein said
second coupler sealingly couples said other end portion to said
inner tank..Iaddend.
.Iadd.30. A discharge outlet as set forth in claim 25, wherein said
boot member includes a circumferentially extending cup-shaped
protrusion..Iaddend.
.Iadd.31. A discharge outlet as set forth in claim 30, wherein said
cup-shaped protrusion has a maximum cross-sectional area greater
than the area of the access opening..Iaddend.
.Iadd.32. A discharge outlet as set forth in claim 25, wherein said
boot member is of a flexible synthetic resin material..Iaddend.
.Iadd.33. A discharge outlet as set forth in claim 25, said boot
member having first and second outer end portions, wherein said
first outer end portion of the boot member has a unitary first
annular wall, a first annular gasket between the side wall portion
of the outer containment vessel and the first annular wall of the
boot member to prevent leakage of fluid from the containment area
of the tank through said access opening of the containment
vessel..Iaddend.
.Iadd.34. A discharge outlet as set forth in claim 33, wherein said
second end portion of the boot member has a unitary second annular
wall and a second annular gasket surrounding the conduit and
sealingly engaging the second annular wall of the boot member to
prevent leakage of fluid from the containment area between the
inner tank and the containment vessel..Iaddend.
.Iadd.35. A discharge outlet as set forth in claim 25, said annular
boot being located within said containment area..Iaddend.
.Iadd.36. A discharge outlet as set forth in claim 25, said inner
tank having a base, an upright sidewall, and an upper end, said
outer containment vessel having a base, an upright sidewall opposed
to said inner tank sidewall, and an upper end, said discharge
outlet located closer to said inner tank and containment vessel
bases than said inner containment and containment vessel upper
ends..Iaddend.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention concerns a discharge outlet for use with a double
wall tank assembly used for storing and dispensing large quantities
of liquid. More particularly, it is concerned with a sealing boot
for the discharge outlet which enables the liquid to be dispensed
through openings in the side walls of the inner tank and outer
vessel of the double wall tank assembly.
2. Description of the Prior Art
Storage of liquid in bulk is well known, and has evolved in
importance due to environmental concerns over the escape of
chemicals. In the past, it was common to store chemicals
underground in large tanks where gravity was used to fill the
vessels and the contents were periodically pumped for use. However,
the problems associated with leading underground storage tanks has
increased the usage of above ground storage tanks. Typically, one
or more above-ground vessels have been placed in a "tank farm"
where a concrete pad and berm help to contain and capture any
problem. Rainwater received in the containment area must be
monitored and treated if leakage is detected. This has proven very
expensive, as the rainwater represents a large volume of liquid
even though the leakage is isolated.
As a result, storage containers have been developed which include a
double walled construction. Examples of containment tanks utilizing
such construction are shown in U.S. Pat. Nos. 5,287,986 to Frost
and U.S. Pat. No. 5,333,752 to Harding, Jr. While the double walled
construction therein is an improvement over single walled tanks,
they require filling and discharge to be accomplished from atop the
tanks. This requires extra energy to be expended in pumping the
liquid. The need to prevent leakage from a double walled
containment tank assembly has thus not heretofore permitted
effective discharge openings through the sidewalls of the component
inner and outer tanks. Thus, there has developed a need for a
containment tank assembly which is capable of use in a variety of
environments, minimizes, leakage, and has reduced energy
demands.
SUMMARY OF THE INVENTION
These objects have largely been met through the discharge outlet
and sealing boot of the present invention. That is to say, the
present invention effectively seals openings provided in the
sidewalls of a containment tank assembly having an inner tank and
an outer vessel. Moreover, the discharge outlet includes a sealing
boot which captures liquid which might leak into the containment
area between the inner tank and outer vessel. Advantageously, the
sealing boot is flexible and thus accommodates relative movement
between the inner tank and outer vessel, such as may be encountered
by expansion of the inner tank during filling and external forces
applied to the outer vessel.
The discharge outlet of the present invention broadly includes an
inner tank flange assembly, an outer vessel flange assembly, and a
sealing boot interconnecting the two flange assemblies, piping or
conduit is preferably provided which extends from the inner flange
assembly exteriorly of the outer vessel for attachment of a valve,
piping or the like to effect the transfer of liquid from the tank.
The sealing boot is preferably of a flexible material and is
provided in the shape of a tire, whereby liquid leaking may be
readily visually detected and repair of the inner tank assembly may
be effected without deterioration of the containment capabilities
of the double wall tank assembly. The piping of the discharge
outlet, which is positioned relatively near the bottom of the side
of the double wall tank assembly, may be further provided with
additional piping interiorly of the inner tank and include a pipe
opening near the bottom wall of the inner tank, thereby
facilitating removal of most of the liquid within the inner tank
when it is desired to be emptied.
These and other advantages of the discharge outlet of the present
invention will be readily appreciated by those skilled in the art
with reference to the drawings and the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a exploded view of a double wall containment tank
assembly, showing the opening in the outer vessel for receiving the
discharge outlet positioned relatively low on the side thereof;
FIG. 2 is a perspective view of the double wall containment tank
assembly shown in FIG. 1 with the inner tank nested in the outer
vessel and showing anchor assemblies for holding the double wall
containment tank assembly against movement relative to the
supporting surface;
FIG. 3 is an enlarged, vertical sectional view taken through line
3--3 of FIG. 2 showing the discharge outlet mounted on the double
wall containment tank assembly; and
FIG. 4 is an exploded view of the discharge outlet hereof.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawing, a discharge outlet 10 in accordance
with the present invention is provided for mounting as part of a
double wall containment tank assembly 12 used for bulk storage of
liquids. The double wall containment tank assembly 12 includes an
inner tank 14, an outer vessel 16, and a plurality of anchor
assemblies 18 for securing the tank assembly 12 to a pad or other
supporting surface 20. The details of the structure of the tank
assembly 12 are further described in my U.S. Patent Application
entitled Containment Tank Assembly filed contemporaneously herewith
as application Ser. No. 09/519,323 filed Mar. 6, 2000, the
disclosure of which is incorporated herein by reference.
In greater detail, the inner tank 14 includes a lower section 22,
an upper section 24 which extends radially outwardly of lower
section 22 and is connected thereto by a lip presenting a trough,
and a roof 26 which acts as a cover to define a liquid-receiving
chamber 28 therewithin. The lip includes a plurality of
circumferentially spaced chutes to permit drainage from the trough
back into the interior of the lower section 22. A plurality of
upstanding lugs 30 project upwardly from the roof 26 for the
attachment of cables 32 of anchor assemblies 18 thereto. The anchor
assemblies 18 also include anchors 34 which are bolted into the
supporting surface 20 (such as a concrete pad) and connected to the
cables 32 by eyebolts 36. A manhole cover 38 is interfitted into a
manhole in the roof 26 to permit access into the chamber 28. The
lugs 30 provide pairs of tie-down flanges 40 and lifting flanges
42, each provided with holes for the passage of cables 32
therethrough. An opening through the side of the upper section 24
permits the attachment of fill pipe 44 thereto. In addition, the
roof 26 receives vent 46, filler inlet 48, and level indicator 50
thereon, the latter including a probe for determining the amount of
the liquid in the chamber 28. The lower section 22 includes a
substantially cylindrical sidewall 52 and a bottom wall 58 which
are joined at the lower perimeter 60 of the sidewall 52. A port 54
is provided in the cylindrical sidewall proximate to the lower
perimeter 60, with four surrounding circumferentially spaced bolt
holes 62 provided through the side wall 52.
The outer vessel 16 includes a multifaceted lower wall portion 64
and a substantially cylindrical upper wall portion 66. The lower
wall portion 64 includes a plurality of alternating arcuate
sections 68 and chord sections 70. The lower wall portion 64 tapers
inwardly in transition area 72 to cylindrical wall portion 66,
which lies closely adjacent the cylindrical sidewall 52 when the
inner tank 14 is nested in the outer tank 16. The upper wall
portion 66 has an upper margin provided with a plurality of notches
74 for receiving the chutes of the inner tank 14 therein. The
arcuate sections 68 are spaced from the cylindrical sidewall 52 of
the inner tank 14 to define therebetween a containment area 76. An
access opening 78 is provided in one of the arcuate sections 68 for
receipt of the discharge outlet 10 therein, with a plurality of
surrounding, circumferentially spaced holes 80 for the receipt of
the bolts therethrough. A leak detection system 82 may be mounted
in the lower wall portion 64 and include a probe extending
downwardly into the containment area 76 to detect the presence of
liquid therein. The base wall 84 connects to the lower wall portion
64 and receives the bottom wall 58 of the inner tank 14 thereon.
Both the inner tank 14 and the outer vessel 16 are rotationally
molded of synthetic resin, such as high density linear polyethylene
or cross-linked, high density polyethylene.
The discharge outlet 10 includes an inner coupler assembly 86, an
coupler flange assembly 88, sealing boot 90, and piping 92. The
inner coupler assembly includes interior flange 94 and intermediate
flange 96 which each include a ring 98 and a neck 100, each flange
94 and 96 having a central opening 102 to permit the flow of liquid
therethrough. Annular gaskets 104 and 106 abut the cylindrical
sidewall 52 in sealing relationship thereto. The rings 98 and
gaskets 104 and 106 each include apertures 108 aligned in registry
with the bolt holes 62 in the cylindrical sidewall 52 for the
receipt of bolts 110 therethrough. The bolts 110 are secured by
suitable nuts and washers.
The sealing boot 90 is located in the containment area 76 and
preferably rotationally molded of synthetic resin such as either
high density linear or low density polyethylene for flexibility.
The sealing boot 90 is provided in the shape of a tire, including a
flat inner wall 112 provided with surrounding, circumferentially
spaced apertures 114 for the receipt of bolts 110 therethrough, and
a central hole 56 for alignment in registry with the port 54 and
the central opening 102 of the neck 100. An circumferentially
extending cup-shaped protrusion 116 extends radially outwardly from
the flat inner wall 112, with flat outer wall 118 extending
radially inwardly therefrom in spaced, opposed relationship to flat
inner wall 112. The flat outer wall 118 includes an inner margin
120 having a transverse dimension .[.D.]. which is substantially
the same as that of the access opening 78 and .[.smaller.].
.Iadd.larger .Iaddend.than the diameter of the central hole 56 of
the flat inner wall 112. The sealing boot 90 thus defines an
annular, circumferentially extending channel 122 which permits
flexing of the boot 90 and captures liquid leaking past the inner
coupler assembly.
The outer coupler assembly 88 has an inner flange provided as
semi-annular inner flange plate halves 124 and 126 positioned
within the channel 122, annular gaskets 128 and 130 sandwiching the
flat outer wall 118 therebetween, and outer flange plate 132 for
engagement against the exterior 134 of the outer vessel. The inner
flange plate halves 124 and 126 and the outer flange plate 132 are
preferably stainless steel or other corrosion resistant metal. The
flat outer wall 118, inner plate halves 124 and 126, gaskets 128
and 130, and outer flange plate include holes which are positioned
in registry with the holes 80 in the outer vessel 16 for receipt of
bolts 136 therethrough. The bolts 136 are secured in place by
suitable nuts and washers as shown in FIGS. 3 and 4. The gaskets
104 and 106 and also 128 and 130 are preferably elastomeric, and
provided of a chemically resistant natural or synthetic rubber
material.
The piping 92 is preferably of a chemical resistant synthetic resin
material such as polyvinyl chloride and provides a conduit for the
passage of liquid in the chamber 28 out of the containment tank
assembly 12. The piping 12 includes a discharge tube 138 having an
inner end which is preferably chemically welded to the neck 100 of
the intermediate flange 96 and an outer end which receives a
connection flange 140 for the attachment of further piping or a
discharge valve to control the flow of liquid from the chamber 76.
An inner tube 142 extends into the chamber 76 and has one end which
is preferably chemically welded to the neck 100 of interior flange
94 and another end which receives thereon elbow 144. The elbow 144
is oriented downwardly and a pickup pipe 146 is connected at one
end thereto, the pickup pipe 146 having an open, lower end 148
adjacent the bottom wall for providing an intake into the pipeline
92 for the discharge of liquid therethrough.
In use, the sealing boot 90 and the access opening 78 of the outer
vessel are trimmed to fit with the flange plate halves 124, 126 and
outer flange plate 132. The flange plate halves 124, 126 are placed
in the channel 122 with the gaskets positioned as shown in FIG. 3
and the bolts 136 are inserted and tightened. The inner tank 14 is
lowered into the outer vessel 14 in nesting relationship with the
chutes received in the inner notches and the port 54 aligned with
the access opening 78. The inner tank 14 is then preloaded, and the
port 54 is trimmed to receive the inner flange assembly 86. The
inner tube 142, elbow 144 and pickup pipe 146 are installed into
the inner flange assembly 86 mounted on the cylindrical sidewall 52
to permit liquid to flow through the central opening 102. The
discharge tube 138 with connection flange 140 is then chemically
welded to the neck 100 of intermediate flange 96, and a control
valve such as a ball valve or further piping is attached to the
connection flange to permit filling of the chamber 28.
The discharge outlet 10 thus effectively permits the inner tank 14
to be emptied of liquid through gravity rather than pumping,
because the integrity of the containment area 76 is preserved by
the sealing boot 90. The boot 90 is sufficiently flexible to permit
limited relative movement between the inner tank 14 and the outer
vessel 16 due to seismic events, wind forces or thermal expansion.
If liquid begins to leak from the inner tank 14 through the inner
flange assembly 86, the leakage is nonetheless contained within the
channel 122 and can be readily visually observed. Other leaking
from the inner tank 14 is confined to the containment area 76
between the inner tank 14 and outer vessel 16, such that even if
the leakage rises above the access opening 78 in the side of the
outer vessel 16, it does not escape.
Although preferred forms of the invention have been described
above, it is to be recognized that such disclosure is by way of
illustration only, and should not be utilized in a limiting sense
in interpreting the scope of the present invention. Obvious
modifications to the exemplary embodiments, as hereinabove set
forth, could be readily made by those skilled in the art without
departing from the spirit of the present invention.
The inventor hereby states his intent to rely on the doctrine of
equivalents to determine and assess the reasonably fair scope of
his invention as pertains to any apparatus not materially departing
from but outside the literal scope of the invention as set out in
the following claims.
* * * * *