Note: Descriptions are shown in the official language in which they were submitted.
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23199A
SPECIFICATION
TO A~L WHOM IT MAY CONCERN:
Be it known thak I, WILLIAM A. SCHNEIDER, a
citizen of the United States of America, resident of
Conroe, County of Montgomery, State of Texas, have
invented a new and use~ul improvement in JOINT FOR TURBINE
ENCLOSURE IN UNDERGROUND TANKS which invention is ~ully
set forth in the following speci~ication.
TEC~NICAL FIELD
This invention pertains to storage tanks
suitable ~or the storage o~ liquids. More particularly,
~his invention relates to tanks which are suitable for
storing such liquids as gasoIine underground.
5~iGROUND ART
Undergrou;nd~stora~e tanks are widely used for
storing gasoline and~other fuels. Typically,~hese tanks
are made from fiberglass reinforced plastic of ~he type
which is~chemically resis~ant~to fuels and other similar
liquids. Such~tanks have received widespread use in
gasol~ine~servLce~stations throughou~ the country. Tanks
sized fo~the~storage of yasoline in service stations
3~0~ usually have a capacity of lO~000~gallons or more. The
tanks~;~are~t~pically made by applying glass strands~ or
choppe~ glass~ibers~along with liquid resin to a rotating
mandrel. ~f~er~the resin curés, the~mandrel i~ removed,
resulting~in~a generally cylindrical tank. Ribs are added
or~structural strength~
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23199A
Underground storage tanks have one or more
openings along the top of the tanks to allow fuel to be
pumped into and out of the tank. Openings are also
provided for monitoring the level of liquid within the
tank. In order to provide access to the tank, and to
house piping, pumps and level monitoring equipment for the
~low of liquids into and out of the tank, a chamber or
enclosure is positioned directly above the tank. This
equipment enclosure chamber is frequently referred to as a
turbine, or a turbine enclosure. T~e turbine is generally
a cylindrically-shaped fiberglass reinforced plastic piece
which is positionad over an opening in the top wall of the
tank. Typically, the tank is fitted with a collar which
surrounds the openingj and which is attached with a water-
tight joint to the top wall of the tank.
The turbine enclosure serves several purposes.
First, it provides a sump to collect any small amounts o~
~uel which may leak ~rom the pumps or piping system
dire~tly above the t~nk, or other secondary containment
s~stems such as double wall pip which is con`nected so
that it drains into the sumpO Second, it shields the
pumps and piping system from dirt or other back~ill
materials. Also, it keeps~ground water~from reaching the
pumps and piping system O
In order to provide a water-tight joint between
3~0~ the cylindrically shaped turbine and the cylindrically
shaped collar, the turbine is typically provided with an
outwardly-flared bottom edge or beIl, which is larger in
diameter~than`the collar, in order to make a bell and
spigot joint connection. The~bell and spigot joint does
~not provide a positive seat for the turbine, and
misali~nment o~thé~turbine is a possibility. During
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23199A
installation of the tank and the turbine enclosure, the
turbine is placed over the collar and a field application
of a sealing material or adhesive must be made to the
connection between the turbine and the collar. The bell
and spigot joint is oriented so that the crack or joint
formed between the turbine and the collar points
downwardly, thereby preventing ground water from running
directly down into the joint. The downwardly oriented
cracX is difficult to fill with adhesive in the field.
Also, after the turbine is applied to the collar, the
backfill operation must be delayed until the joint is
sealed. Further, the seal is not visible during the
useful operation of the tank since the joint is buried by
the backfill.
An additional problem with the ~ield joint which
is pointing downwardly outside o~ the turbine enclosure is
that being on the outside surface, it is difficult to
apply heat to the adhesive material in cold weather in
order to accelerate the hardening or curing o~ the
adhesive. Finally, the joint, being on the outside of the
turbine, is exposed to the elements during the curing
process, rather than being something readily covered up to
prevent its being affected by weather elements.
There is a need for a turbine enclosure joint
; which provides a watertight ~eal and can be readily
30~ applied. Further, the joint should be positioned so that
; ~it ca~ be readily inspected for possible failure during
the liPe of the tank. Also, the joint should be one that
establishes~a positive seat ~or the turbine wall on the
collar, to avoid the situation of misalignment of the
turbine wall on the collar.
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23199A
DISCLOSURE OF THE INVENTION
A11 of the above outlined problems in providing
a turbine enclosure on top of an underground storage tank
can be overcome by using a joint in which the collar has
; an upwardly and radially inwardly flaring flange so that
the joint is made on the inside of the turbine enclosure,
rather than on the outside of the turbine enclosure. The
upwardly and radially inwardly flaring flange and the
turbine wall define an annular crack or space having a v-
shaped cross-section. This crack can be filled with
adhesive material to provide the seal, thereby preventing
liquids from traveling into or out of the turbine
enclosure. The ssal also provides structural rigidity to
the turbine wall.
Since the crack is facing upward and inward, the
joint can be readily inspected during the life of the
tank. Also, since the join~ is applied within the turbine
' enclosure, the installation process and the sealing of the
joint is greatly facilitated for the following rea~ons:
the joint can be sealed after the backfill operation has
been concluded; the joint faces upward, thereby making it
easy to apply the adhesive into the crack;~the joint is
completed in an e~closed spac~, thereby making it easy to
apply heat to~the joint when ambient temperatures are
below~the recommended temperature range for the adhesive;
30~ and, the turhina can be readily covered during curing of
the adhesive to limit the effects of weather
characteristLcs~ The joint for the turbine enclosure of
the invention~also includes a flat, upwardly facing
surface adapted to receive the bottom edge of the turbine
3$~ ~in~order to~provide~a positive seating of the turbine wall
on the collar.
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23199A
According to this invention, there is provided a
storage tank suitable for underground containment of
liquids comprising a tank wall having a bore therethrough,
an upwardly prot~uding collar mounted on the tank and
circumscribing the bore, the collar having at its upward
end a flange which turns inwardly toward the interior of
the collar, the flange being at an angle to the vertical
within the range of ~rom about 5 degrees to about 75
degrees, the collar and flange being suitable for mating
with a turbine to form a turbine enclosure.
In a specific embodiment of the invention, the
collar has an upwardly facing surface adapted to receive
the bottom edge of a turbine. Preferably, the upwardly
facing surface is positioned where the flange is attached
to the collar.
According to this invention, there is provided,
in combination, a turbine and a storage tank suitable for
underground containment of liquids, the tank comprising a
tank wall having a bore therethrough, an upwardly
prokruding collar mounted on the tank and circumscribing
25~ the bore, the collar having at its upward end a flange
; ~ which turns inwardly toward the interior o~ the collar,
the flange~being at an angle to the vertical within the
range of~from about 5~degrees to a~out 75 degrees, the
collar and flange being suitable ~or mating with a turbine
30~ to f~orm a turbine enclosure, the turbine being positioned
on the~collar so that the flange is positioned within the
turbine, and~a sealing material placed~within the space
between the flange and the turbine.
In a preferred~embodiment of the invention, the
35~ ooIlar and the turbine are circular, and the flange and
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23199A
turbine define an annular space having a v-shaped cross-
section.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic view in cross-section of
a storage tank and turbine enclosure according to the
1 principles of the invention~
Figure 2 is a schematic cross-section of the
- ~ turbine enclosure of Figure 1.
Figure 3 is a schematic view in cross-section of
the joint between the collar and the turbine sidewall,
with the joint space being filIed by adhesive, according
to the principles of the invention.
BE.~T MODE FOR CARRYING OUT THE INVENTION
As shown in Fig~re 1, the storage tank is
comprised of tank wall 10, having bore or tank opening 12
positioned in the top portion of the tank wall. The tank
can be o~ any suitable design, such as a fiberglass
reinforced tank, preferably with ribs 14 for
rein~orcement. The tank can be a double wall tank or a
single wall tank. Cir~umscribing ~the tank opèning is
collar 16. Preferably, the tank opening and the collar
are circular. The~collar protrudes upwardly from the top
of the~tan~.~ As shown more clearly in Figure 2, the
collar has~ flange 18 a~its~upward end which turns
radially-inwardly toward the interior of the collar.
30~ ~Positioned on~the~collar is~turbine 20, comprised of
cy1indrica`1 turbine sidewall 22. Turbine top 24 can ~lso
be positioned~on~top o~ the turbine sidewall. The
~ circular or annuIar turbine sidewall defines the turbine
s~ enclosure 26. ~Preferably, the turbine is made of
S~ fiberglass rein~orced plastic mate~ial. Such turbines are
well known in~the art.
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23199A
As shown in Figures 2 and 3, the collar has an
upwardly facing surface, such as alignment step 28,
adapted to receive the bottom edge 30 of the turbine.
This assures that the turbine sidewall is positively
seated on the collar. Preferably, this surface is flat to
evenly mate with the turbine bottom edge. Also, the
alignment step is of the same diameter as the bottom edge
of the turbine.
The collar is adapted with vertical alignment
surface 36 which mates with turbine lower inner surface 38
of the turbine to form a snug fit. Thase mated vertical
seGtions -- the alignment surface and the bottom inner
surface -- prevent the turbine from rocking upwards on one
i side when downward pressure is applied to the other side,
such as when someone is climbing out of the tank opening
i 20 during or after installation.
As can be~seen, the inner flange and the turbine
sidewall define annular joint space 32, which has a v-
shaped cross-section. The joint space can also be viewed
às an annular crack running all the way around the turbine
~;25~ sidewall. To complete the installation of the joint,
; adhesive 34 is appIied into the joint space, as shown in
Fiyure 3. The preferred adhesive is CL-200 by Fibercast
Company, Sand Spring, OK, modified by a 50% addition of a
vin~l ester resin for greater flowability.
30~ The inner flange is oriented at an angle to the
vertical or to the turbine sidewall. This angle is within
the ~angé of~from about 5 degrees to about 75 degrees, and
preferably within the range of from about 10 degrees to
about 4;5 degrees. Most preferably, the inner flange is at
35~ an angle of about 20 degrees to tha vertical. Also, the
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23199A
alignment step is preferably positioned where the flange
is attached to the collarO
Various modifications may be made in the
structure shown and described without departing from the
scope of the invention.as set.forth in the following
claims.
INDUSTRIAL APPLICABILITY
This invention will be found to be useful in the
manufacture and installation of fiberglass reinforced
plastic underground storage tanks for the storage of
liquids.
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