Storage tank shut-off valve

An improved control valve for a holding tank is provided for cutting off the flow of fluid into a holding tank device in response to achieving a predetermined fluid level in the holding tank. The assembly includes a housing configured for placement adjacent a spill container. The housing has an upper inlet and a lower outlet and a flow passage therebetween having a diameter of which is substantially constant along its longitudinal length. A valve poppet is situated within the flow passage and is axially rotatable between a substantially vertical, open position, that allows for the flow of fluid through the flow passage, and a closed position substantially blocking fluid flow through the flow passage when the holding tank has reached a predetermined level of fluid.

TECHNICAL FIELD OF THE INVENTION 
The present invention relates generally to shut-off valves for storage 
tanks, and, more particularly, to an improved hydraulically operated 
shut-off valve assembly featuring a substantially unencumbered flow 
passage having minimal pressure change along its length for high flow, and 
a high sensitivity shut-off mechanism for automatically cutting off the 
flow of liquids to a storage tank in response to the fluid level in the 
tank reaching a pre-determined fill level. 
BACKGROUND OF THE INVENTION 
It is very common to use storage tanks for a variety of fluids such as 
gasoline, diesel fuel, and oil and these storage tanks are usually filled 
through openings adjacent to or above the top of the tanks. Such openings 
usually have relatively small diameters that are sized to receive the 
dispensing elbow tube of a dispensing tube from a tank truck or other 
supply source. In most cases, these storage tanks are not equipped with 
gauges, and the operator filling the storage tank has no direct visual 
access to the internal space of the storage tank. Additionally, no other 
additional practical and reliable way of determining whether the storage 
tank is approaching a full level, while being filled, is generally 
available. 
As a consequence of these factors, proper filling of storage tanks is a 
universal concern, as overfilling of storage tanks may result in spillage 
of the tank contents, damage to the tank or filling equipment, 
contamination of land or ground water, or other serious and potentially 
dangerous results. Concerns over spillage of the tank contents is 
particularly acute when the contents being filled into the tank are 
flammable, toxic and/or environmentally hazardous. The problems associated 
with overflow spillage from the filling of storage tanks has become so 
recognized that many local governments now require some liquid storage 
tanks to be filled only with equipment that automatically shuts off the 
flow of the liquid to the storage tank when full. 
There have been a number of prior attempts to provide an overflow valve to 
address these problems, however, most of these valves require extensive 
modification to the existing storage tank set up, such as in Europe where 
the storage tank is remote or have other less than acceptable attributes. 
One such valve to be attached to the top of the storage tank is described 
in U.S. Pat. No. 4,770,317 (Podgers, et al.). In this device, the liquid 
fill passage is narrowed in diameter at a discrete portion between its 
inlet and outlet ends to establish a pressure drop in the valve. A 
pressure responsive latch engages the valve and releasably locks the valve 
in the open position. A vent passage has one open end in the storage tank 
at a pre-determined level and another open end communicating with the 
latch. As liquid flows through the passage, a pressure drop or partial 
vacuum is formed where the diameter of the passage narrows. The vacuum is 
vented through the vacuum passage while liquid in the storage tank is 
below the bottom end of the vent passage. When liquid rises to the level 
of the end of the vent passage, the pressure causes the latch to release 
and the valve to close off the passage. 
There are, however, several drawbacks to devices such as taught by Podgers, 
et al. First, the valve must be reopened/reset manually after it is 
closed. In addition, the housing for this valve is generally not 
retrofittable to existing storage tank arrangements. Such valves must 
generally be installed permanently in the ground and secured to the riser 
pipe extending upwardly from the storage tank. In addition, valves of this 
type require a relatively high flow rate to effectuate closing of the 
valve, and the required narrowing of the flow passage limits operable fill 
rates. 
Other valves heretofore available have also been found to be deficient. 
Some valves require complex installation, where substantial field assembly 
must be undertaken to custom fit the valve to the storage tank. Other 
valves have physical structures which cause obstructions in the liquid 
flow passageway itself, making it difficult or impossible for an operator 
to insert a dip stick through the valve to manually determine how much 
liquid is in the storage tank. In many installations, "sticking" is the 
only way to determine the fluid level of a tank, and the only way to 
prevent overfilling. 
Other prior shut-off valves utilize swing-arm type reciprocating float 
controls to operate the valve closure in response to the rising fluid 
level in the tank. Some storage tanks have a permanent riser tube extended 
upwardly from near the bottom of the storage tank and permanently secured 
thereto, makes it impossible to use a swing float-type valve as an 
automatic shut-off valve. Generally, modifications must be made to the 
riser tube to enable the swing action of the valve within the upper 
portions of the tank. Examples of such shut-off valves and drop tubes are 
illustrated in U.S. Pat. No. 4,986,320 to Kesterman, et al. and U.S. Pat. 
No. 4,667,712 to Draft. 
Many previously available valves utilizing float valve activators must also 
be placed lower in the tank to allow sufficient operating room, thereby 
also increasing the ullage and effectively limiting the useable volume of 
the holding tank itself. Many of these valves must also be manually reset 
once they are triggered closed, in order to prevent further flow of fluid 
and possible overfilling. This manual reset requirement leaves another 
possibility for inadvertent failure which can result in overfilling and 
spills. 
Many of the previously available valves do not provide for any misfit 
between the edge of the valve and the interior wall of the flow passage so 
that liquid can drain after flow is shut off. Instead, those valves have 
secondary passageways which allow for slow drainage, sometimes exceeds one 
minute after the valve is closed. 
In the past, many valve assemblies used as a shut-off valve for storage 
tanks were made to withstand the shock of having flow through the 
passageway abruptly terminated when the valve closes while liquid is still 
flowing into the assembly. This configuration requires more material to 
construct and makes it expensive to manufacture. Also, prior valves 
require a minimum flow rate through the flow passageway of between 150 and 
250 gallons per minute (570 and 950 liters per minute) to be operative. A 
lower flow rate through the passageway make the valve inoperable and this 
becomes problematic, especially when filling a storage tank without a 
pumping mechanism to increase flow of liquid. As a result, it can be seen 
that the shut-off valves heretofore available have a number of 
shortcomings, and an improved valve with substantially unencumbered flow 
characteristics, easily retrofittable onto casting equipment, and 
featuring improved sensitivity and automatic resetting functions was 
needed. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide an improved shut-off 
valve which overcomes the problems and shortcomings of valves known or 
available heretofore. 
It is also an object of the invention to provide a decoupled shut-off valve 
and activator that automatically reset independently of each other after 
the valve closes in response to a predetermined liquid level in the 
holding tank. 
It is another object of the invention to provide a valve assembly that 
allows a dip stick to be inserted thought he flow passage to measure the 
liquid level in the holding tank. 
Another object of the invention is to provide a fully assembled valve 
assembly that can be more easily mounted in pre-existing spill containers 
and used on riser tubes permanently attached to a holding tank. 
It is also an object of the invention to provide for substantially laminar 
and constant pressure flow through the flow passage so the valve is 
affected by flow therethrough until the valve closes in response to a 
predetermined level in the holding tank. 
Another object of the invention is to provide a decoupled valve and 
activator system that features increased sensitivity to respond to a 
minimal change in pressure upon the fill level in the tank being attained. 
Another objective of the invention is to provide a shut-off valve device 
that can be added to an already existing holding tank and spill container. 
It is also an object of the invention to provide a shut-off valve that 
allows quicker drainage of the liquid head once flow is terminated into 
the assembly. 
It is an object of the invention to provide a hydraulically operated valve 
that can be activated with a reduced flow rate through the flow passage 
and activator system. 
Another objective of the invention is to provide an assembly that can 
withstand the shock when the valve substantially closes cutting off the 
flow of liquid through the flow passageway. 
Additional objects, advantages, and other features of the invention will be 
set forth and will become apparent through the description that follows, 
and, in part, will become apparent to those skilled in the art upon 
examination of the following, or may be learned with practice of the 
invention. The objects and variants of the inventions may be realized and 
attained by means of the instrumentalities in combinations particularly 
pointed out in the appended claims. 
To achieve the foregoing and other objects, and in accordance with the 
purpose herein, an improved spill control valve for a holding tank is 
provided for cutting off the flow of fluid in response to achieving a 
predetermined fluid level in the holding tank. The assembly includes a 
housing configured for placement in a spill container. The housing has an 
upper inlet and a lower outlet and a flow passage therebetween having a 
diameter of which is substantially constant along its longitudinal length. 
A valve poppet is situated within the flow passage, and is rotatable 
between a substantially vertical, open position, that allows for the flow 
of fluid through the flow passage, and a closed position substantially 
blocking fluid flow through the flow passage when the holding tank has 
reached a predetermined level of fluid. 
An aspirator located at least partially within the housing creates a slight 
underpressure, and comprises a sensing tube inlet extending downwardly 
into the holding tank with its lower end situated at a predetermined 
maximum fill level within the holding tank. The aspirator is operably 
connected to the valve assembly for urging the control valve from its 
opened position toward its closed position in response to the change in 
pressure in the aspirator when the fluid level within the tank reaches the 
lower end of the sensing tube. 
The assembly also preferably has a deflector in the flow passage secured 
above the valve poppet. The deflector is configured to protect the valve 
from the insertion of a dip stick, and to help isolate the valve in its 
vertical open position from fluid flowing through the flow passage during 
filling procedures. When the predetermined fluid level is reached within 
the tank, an activator assembly responds to the change in the 
underpressure within the aspirator, urging the valve poppet from its open 
position toward its closed position to shut off the flow of fluid through 
the control valve. 
A means is provided for automatically resetting the control valve to its 
open position once fluid flow has ceased. In a preferred embodiment, the 
activator assembly includes a pressure sensitive reciprocable piston which 
automatically resets once fluid flow has stopped independently of the 
automatic reset of the poppet valve. This independent resetting is 
achieved as a result of the decoupled nature of the activator piston and 
the poppet valve. In a most preferred arrangement, the activator piston is 
normally biased to its non-activated or valve-open position, and the valve 
poppet is unevenly weighted to facilitate resetting to a normally open 
position.

Reference will now be made in detail to the present preferred embodiment of 
the invention, an example which is illustrated by the attached drawings. 
DETAILED DESCRIPTION OF THE INVENTION 
Referring now to the drawings in detail, wherein like numerals indicate the 
same elements throughout the views, FIG. 1 shows a schematic view of 
relatively conventional holding tank fill arrangement in which the present 
invention can be advantageously utilized. Particularly, FIG. 1 shows a 
tank truck 10 used for transporting a flammable liquid such as gasoline, 
diesel fuel, oil, kerosene or like fluids. The truck 10 is parked near a 
holding tank 12 shown as an underground installation for illustrative 
purposes. Fluid (e.g. gasoline) within the truck 10 is discharged by 
gravity alone, and flows to the holding tank 12 through a dispensing line 
11. The holding tank 10 has a riser 14 extending upwardly from adjacent 
the top of the tank 12 to a spill container 16. Within the riser 14, in 
many installations, a drop tube 28 lines portions of the riser 14 and 
extends to near the bottom of the tank 12. In some applications, the riser 
and drop tube structures are provided as a substantially continuous, 
permanent, structure. 
The present invention can advantageously be used in service stations where 
the operator must remain in attendance during the filling operation to 
close off the truck outlet when the tank 12 has reached a predetermined 
level of fill. The present invention provides an automatic overflow 
prevention, fluid flow operated control valve device (e.g. 18) which can 
be mounted in a spill container (e.g. 16). The device 18 has a housing 20 
that is preferably provided of a hard coated and/or wear resistant 
material for protection against corrosion and other deterioration which 
can result from exposure to fluids such as gasoline, chemicals and the 
like, as well as hard use and other environmental influences such as water 
or salt. In a preferred embodiment, the housing 20 (as seen in FIG. 3) is 
made from cast aluminum and finished with a hardcoat anodize. As shown in 
FIG. 3, a collar 21 is also provided for securing a fluid dispensing elbow 
on line 11 to the housing 20 via a Kam-Loc or threaded connection. In a 
preferred embodiment, the collar 21 includes an integral adapter ring 37 
for accommodating conventional Kam-Locs and the like. 
The housing 20 has a central, longitudinal flow passage 24 that extends 
between an upper inlet (e.g. 25a) and a lower outlet (e.g. 25b) wherein 
the diameter (D) remains substantial constant throughout its longitudinal 
length. Located adjacent the upper inlet 25a, and at least partially 
within passage 24, is a deflector 30 and aspirator shelf 26, as shown in 
FIG. 4 which are discussed in detail below. As used herein, the term 
"substantially constant" is used to connote that flow passage 24 is not 
significantly changed along its longitudinal length to cause any 
substantial changes in the fluid flow rate or volume as it passes through 
valve assembly 40. This is important, as many previously available valve 
structures have required diameter changes somewhere along their length to 
create pressure differences and/or to otherwise control the flow of fluid 
through the valve. As mentioned above, these physical restrictions and 
diameter changes also tend to result in less efficient valve structures 
and less desirable performance results. As will be appreciated, while 
aspirator shelf 26 will extend outwardly into the flow of fluid somewhat 
within flow passage 24, the presence of this structure does not 
significantly obstruct the fluid flow through valve assemblies made in 
accordance with the present invention. 
As best illustrated in FIGS. 3-7, a valve assembly 40 is preferably located 
within flow passage 24 about mid-way along the longitudinal length of 
housing 20. Valve assembly 40 preferably includes a shut-off valve poppet 
41 which is rotatably mounted within flow passage 24 such that it will 
have a substantially vertical, open position or condition (as best seen in 
FIGS. 4 and 5), and a laterally rotated closed position or condition (as 
best seen in FIG. 7). As will also be appreciated, valve poppet 41 is 
preferably rotatably mounted within housing 20 via a rotational shaft 49, 
which may or may not include bearings at its opposite ends to reduce 
rotational friction. Valve poppet 41 can be provided of any corrosion 
resistant and non-sparking material such as cast aluminum, stainless 
steel, or a combination of materials such as zinc or aluminum alloy. 
Rotational shaft 49 can be mounted in a conventional arrangement within 
the oppositely disposed aft bearings or bores 63, and may be clearance fit 
through valve poppet 41 from the exterior of housing 20, such as via 
opening 99. Such opening is preferably sealed against leakage, such as via 
the threaded pipe plug 100, once the shaft and poppet arrangement have 
been satisfactorily mounted. 
As best seen in FIGS. 3 and 4, it is also preferred that shaft 49 be offset 
slightly from passing through the center of valve poppet 41. This 
eccentric rotational arrangement is preferred in order to assist in the 
closing and reset functions of valve assembly 40. As best seen in FIG. 3, 
the axis of rotation of valve poppet 41 (e.g., R) will preferably be 
offset from the effective center line (C) of poppet 41 such that the upper 
or first portion 45 of poppet valve 41 is slightly oversized with respect 
to the lower or second portion 47 thereof. As will be better understood 
from the details set forth below of the operation of the present 
invention, when actuated for closing procedures, the oversized first 
portion 45 of poppet valve 41 will be thrust outwardly and into the 
incoming fluid stream, and forced downwardly by the flowing fluid into 
closed position with more force than fluid flow will oppose the closing 
procedures by interaction of the fluid flow with the smaller lower portion 
47 of valve 41. This structural arrangement also enables the valve 
assembly to effectuate positive and rapid closing even though the valve 
poppet is physically decoupled from the actuator assembly elements once 
the closing procedure has been initiated. As will be explained, while 
decoupling of the activator structure from the poppet is not imperative 
for a structure made in accordance with the present invention, it is 
advantageous to minimize the complexity of the overall product, and to 
facilitate the automatic resetting features of the device. 
As can be appreciated from a review of FIGS. 3 and 4, when poppet valve 41 
is in open position the valve assembly 40 is preferably substantially 
isolated from the dynamics of fluid flowing through flow passage 24. This 
isolation is preferably provided via a deflector 30 which can be rigidly 
mounted adjacent the upper portions of housing 20 and at least partially 
within flow passage 24. As best illustrated in FIG. 4, deflector 30 
preferably comprises an outwardly and downwardly (i.e., from top to bottom 
of housing 20) flared or tapered surface 31. It has been found that for 
some installations, especially those including a significant bend or elbow 
in the fill line adjacent to housing 20 of the present invention, fluid 
flowing into valve assembly 18 of the present invention may be relatively 
turbulent and otherwise non-laminar in character. Tapered surface 31 has 
been found to facilitate isolation of the poppet valve 41 from turbulent 
fluid flow which might otherwise cause the premature closure of valve 41, 
and to facilitate maintaining substantially laminar flow of fluid through 
the control valve of the present invention. As will be appreciated, 
deflector 30 generally isolates the upper portions of valve poppet 41 from 
axially flowing fluid adjacent the top of housing 20, however, cannot 
prevent turbulent fluid from laterally deflecting the poppet valve from 
its substantially vertical open condition throughout its longitudinal 
journey through the control valve 18. Lateral fluid forces on the poppet 
valve 41 could potentially displace the valve from its substantially 
vertical position, which would subject it to downward and closing forces 
from the inflowing fluid. 
To provide additional isolation for poppet valve 41 in its open condition, 
it is preferred to provide deflector 30 with an extension element 32 which 
extends downwardly within flow passage 24 and laterally across the 
diameter of such flow passage to provide a substantially parallel shield 
adjacent and behind the upper portion 45 of poppet valve 41. This 
deflector extension 32 thereby prevents lateral fluid forces (i.e. 
generally in the direction indicated by arrow F on FIG. 4) from 
inadvertently displacing poppet valve 41 into the fluid flow path during 
filling procedures. 
As best illustrated in FIG. 3, the upper edge (e.g., 34) of deflector 30 is 
preferably downwardly scalloped to accommodate the attachment of a 
conventional adaptor or convex dust cover (not shown) which is often 
utilized to cover the fill inlet of a storage tank. In use, deflector 30 
and its extension 32 prevent the initial burst of fluid flowing into flow 
passage 24 from prematurely closing valve poppet 41, and help establish a 
fluid flow of substantially laminar through the longitudinal length of 
flow passage 24. As will also be understood, the thickness "th" of 
deflector 30 can be maintained sufficiently narrow to allow easy 
longitudinal extension and removal of a dipstick or similar fluid level 
indicating device through flow passage 24, while sufficiently isolating 
the valve assembly 40 from fluid flow and from damage from inserted 
dipsticks and the like. It is contemplated that deflector 30 can be 
attached to housing 20 by a variety of conventional means including a 
slot/press fit arrangement, welding, adhesives, and other fastening means. 
As best illustrated in FIG. 4, an aspirator shelf 26 is preferably provided 
along the lower portion of an outside wall (e.g., 23) of flow passage 24. 
This shelf can be integrally formed with housing 20, or attached as a 
separate piece through conventional methods. Provided through shelf 26 is 
a longitudinal aspirator bore 58 for connection with a downwardly 
depending suction tube 56. The inlet 57 for suction tube 56 is preferably 
flush with the top surface of aspirator shelf 26, while the tube 56 
extends vertically downwardly from below inlet 57 and the lower part of 
shelf 26. As will be understood, aspirator bore 58 is formed with a 
smaller upper diameter (D1), which directly communicates with a lower bore 
diameter (D2) along its longitudinal length. 
The difference between diameters D1 and D2 is important, as it must be 
predetermined to create an underpressure when fluid flows therethrough. It 
has been found that the difference in diameters D1 and D2 must be 
sufficiently large to create a predetermined underpressure (e.g., a vacuum 
pressure of between about 0.5 and 2 psi), yet not so large as to cause the 
flowing fluid to detach from the outer diameter of the tube as it flows 
downwardly. Particularly, diameters D1 and D2 must be sufficiently close 
to one another in relative size such that fluid flowing through the 
smaller diameter will effectively expand such that the meniscus of the 
fluid allows the flowing fluid to reattach to and substantially fill the 
larger diameter tube as it flows downwardly. This reattachment is critical 
to form an underpressure adjacent the diameter change within suction tube 
56. This underpressure will be effected through connecting tube 66 which 
provides fluid communication between suction tube 56, aspirator sensing 
tube 51, and a connected vacuum passage 93 which will be described in 
greater detail below. This underpressure will create an aspirator effect, 
and will effectively withdraw air from the storage tank via sensing tube 
51 during filling operations. 
Aspirator shelf 26 is also provided with a blind bore for sensing tube 51 
having a downwardly extending adjustable length tube (51a) which is placed 
in fluid communication with aspirator bore 58 via connecting tube 66 
extending therebetween. Upon installation, the extension 51a of sensing 
tube 51 is cut to length such that its inlet edge 53 is located at the 
maximum desired fluid level (i.e., the "full" level) of the tank. This can 
be accomplished by cutting the tube extension 51a such that its lower edge 
53 is located at the maximum desired fluid level in the tank. While it may 
be preferred to mount sensing tube 51 and/or suction tube 56 on the 
exterior of a drop tube (e.g. 28), as shown in FIG. 5, in order to 
minimize potential turbulence of fluid flowing within flow passage 24, it 
is not required. A protector 101 having a tubular configurating and 
substantially fitted around the outside of sensing tube 51 is provided to 
prevent inadvertent cutting of the sensing tube 51 when the tube 51 is 
being cut to customize the valve device 12. The protector 101 can also 
hold the sensing tube 51 in place eliminating the need for brackets to 
holding sensing tube 51 in place. 
During filling operations, fluid flowing through longitudinal bore 58 of 
suction tube 56, and into longitudinal bore 59 of larger diameter creates 
a slight underpressure which tends to pull ambient air inwardly through 
sensing tube 51 and connecting tube 66. The varying diameters of suction 
tube 56 (i.e., bores 58 and 59), connecting tube 66, and sensing tube 51 
will vary according to the application, but will be chosen to provide an 
effective aspirator device which will establish a vacuum or underpressure 
of predetermined relative size (e.g., between about 0.5 and 2 psi). The 
longitudinal length of suction tube 56 will generally be as long as 
possible to provide a significant head to establish the desired 
underpressure in the aspirator, and will generally be of substantially 
equal length with the upper drop tube 28 extending downwardly within the 
holding tank. 
Connecting tube 66 will preferably have a diameter determined so that it is 
large enough to prevent fluid flowing through suction tube 56 from easily 
flowing into connecting tube 66 and/or restricting air flow therethrough, 
and such that it is not so small as to prevent drainage of condensation or 
other fluid which might make its way into tube 66 in use. In an exemplary 
embodiment, connecting tube 66 may be a bore having a diameter of 
approximately 1/16" (1.6 mm). The connecting tube 66 might be formed by 
drilling from the exterior of housing 20 (e.g. via access opening 36 and 
access bore 37). Following drilling operations, access opening 36 might be 
sealed by a threaded pipe plug (e.g. 38) or similar sealing arrangement. 
The valve poppet 41 is moved from its open position (FIGS. 4 and 5) toward 
its closed position (FIGS. 6 and 7) by an activator assembly 70 or similar 
means that is responsive to relatively small changes of pressure in the 
aspirator. In a preferred arrangement, activator means 70 includes an 
activator shaft 71 having a first end 71a and a second end 71b. To 
minimize friction and to increase sensitivity, a roller 72 is freely 
rotatable mounted on pin 78 attached to shaft 71. In a preferred 
embodiment, the surface of the roller 72 has a minimal coefficient of 
friction to allow easy movement against a tapered activator ramp 48 
preferably attached to valve poppet 41. Activator shaft 71 may be made of 
any corrosion resistant and non-sparking material, such as stainless 
steel, and is preferably laterally reciprocally situated in flow passage 
24 with its first end 71a received in a support/guide channel 74 formed in 
the housing 20. 
It is preferred that the activator shaft 71 be non-rotatably mounted to 
maintain the alignment of roller 72 with ramp 48, such as by featuring a 
non-cylindrical (e.g., square) cross-section, as illustrated adjacent 
second end 71b. That squared end 71b is shown as being mounted through a 
shaft bore 98 formed through housing 20, and held there within by a 
bushing 76 having a complimentary inner conformation for facilitating 
lateral reciprocation. The activator shaft 71 might have a square 
cross-section only adjacent its first end 71a to facilitate formation of 
support/guide channel 74, as it is much simpler to bore round channels 
into housing 20. The bushing 76 is similarly preferably configured to be 
inserted and secured in a circular cross-section hole 98 in the housing 
22, and is preferably made from a low friction material such as plastic. 
As seen best in FIGS. 4-7, the end of the second portion 47 of poppet 41 
(e.g. at 44) for allowing for the valve 41 to remain substantially 
vertical in its open position without the valve 41 interference from the 
activator shaft 71 and roller 72 on shaft 71. As shown in FIG. 5, attached 
to the valve 41 is a counterweight 42. The weight 42 preferably provides 
sufficient mass so that the valve's center of gravity is in the second 
portion 47. As will be appreciated, this preferentially loading of poppet 
41 is illustrated as a preferred means to facilitate automatic resetting 
of the poppet to its normally open position. In one embodiment, 
counterweight 42 is attached to the valve 41 using screws. In a preferred 
embodiment, the counterweight 42 and valve 41 are provided as an integral 
unit, and can be formed as a single piece. 
The second end 71(b) of shaft 71 is preferably secured to an actuator 
member of piston 86. Particularly, adjacent to housing 20 and aligned with 
shaft 71 is an actuator assembly 70 for closing valve 40 when fluid level 
in a tank has reached a predetermined minimum. A preferred means for 
undertaking this function comprises an actuator piston 86 to initiate 
closure of valve poppet 41. Piston 86 is preferably a simple, cup-shaped 
member mounted for lateral reciprocation between non-actuated and actuated 
positions within a substantially hollow, sealed cylinder or cap 80. As 
seen best in FIG. 3, a screw 75 can be used to secure piston 86 to shaft 
71. The piston 86 has a height "h" which can serve, in conjunction with 
the internal shape of cap 80, as an ultimate stop to determine the stroke 
of piston 86 therewithin. 
A rolling diaphragm seal 82 is preferably disposed around the piston 86 to 
form a flexible static seal of piston 86 and chamber 96. Diaphragm 82 can 
be a Bellow-Frank type (such as available from Bellofram) that is 
resilient and tapered such that it inverts and rolls back to its fully 
extended condition with minimal resistance in response to movement of 
piston 86. The diaphragm 82 has a diameter corresponding to the outer 
diameter of piston 86 and the inner volume of chamber 96, and, in an 
exemplary embodiment might have a stroke length of about 3/4" (19.05 mm). 
In such an exemplary application, 2.31 inches (58.67 mm), and diaphragm 
might have a thickness of about 0.017 inches (0.43 mm). Diaphragm 82 will 
preferably be formed of fluid resistant, flexible materials, such as fuel 
resistant nitrile, fluorocarbon, or similar compounds. 
A biasing means such as stainless steel compression spring 84 shown in FIG. 
3 is preferably situated between the piston 86 and a diaphragm cap 80. 
This biasing means provides a predetermined pressure (e.g., about 0.7 psi) 
against the piston 86 to generally maintain the actuator assembly in 
"open" condition, as seen in FIG. 5. As can be appreciated, when piston 86 
is in "open" or non-actuated position (FIGS. 3 & 5), biasing means 84 will 
be in its fully extended position, tending to hold the piston against 
diaphragm 82 and washer 83. Particularly, washer 83 is shown as comprising 
a shallow cup-like piece corresponding in shape and size to the outer 
portions of piston 86. During assembly, diaphragm 82 is effectively 
sandwiched between piston 86 and the washer 83, whereby diaphragm will be 
effectively held in place and protected from damage by the combination of 
the piston and the washer. 
As can also be seen in FIG. 3, when piston 86 is in its non-actuated or 
open condition, the sidewalls of diaphragm 82 are effectively folded on 
one another (or inverted) in a bellows-like fashion, with the outer 
portions of diaphragm 82 being held in sealed condition via the outer 
diaphragm bead 85. Bead 85 provides an effective O-ring seal between 
diaphragm cap 80 and housing 20, and simultaneously serves to hold 
diaphragm 82 in position within bead groove 88. While other forms of seals 
can be effectuated in ways available to those of ordinary skill in the 
art, the flexible diaphragm/O-ring bead arrangement has been found to be 
quite effective, substantially frictionless, and reliable. The inner 
portions of piston 86 can preferably be formed with a nub or bushing for 
receiving and holding biasing spring 84 in position and a similar 
retaining protuberance 95 can also be formed on the inner portions of cap 
80. 
Enclosing chamber 96 is diaphragm cap 80 which is sealingly mounted to 
housing 20 as described above. Preferably, cap 80 is removable for 
assembly ease, and possibly, maintenance, and attaches to housing 20 via 
screws or the like (not shown). Connecting chamber 96 to the aspirator 
means 50 is a diaphragm vent or vacuum passage 93. Passage 93 provides 
fluid communication between connecting tubes 66 and the internal volume of 
piston chamber 96. The passage 93 is connected to the outer portions of 
diaphragm cap 80 so that as piston 86 reciprocates to its actuated or 
"closed" position (i.e., see FIG. 6), the diaphragm 82 will not block 
vacuum passage 93. In an exemplary embodiment, vacuum passage 93 has a 
diameter of about 3/16" (4.01 mm) and extends within cap 80 to housing 22 
to connect with tube 66 and suction tube 56. At the connection between the 
cap 80 and housing 22, an O-ring seal 91 is preferably provided for the 
connection of passage 93 therethrough. 
In operation, a dispensing or fill line 11 may be connected either directly 
to shut-off valve assembly 18 (e.g., via the locking ring 37), or to an 
inlet tube thereabove. Poppet valve 41 is normally maintained in open 
condition as shown in FIG. 5 as a result of its preferentially weighted 
lower portion 47 and the automatic resetting nature of the present 
invention. As liquid flow is commenced from its source (tank truck 10), 
incoming liquid enters flow passage 24 where it first encounters deflector 
30 which tends to reduce turbulence and create laminar flow within valve 
40. Deflector 30 normally tends to isolate poppet valve 41 from the fluid 
flowing through shut-off valve 18, and deflector extension 32 prevents 
lateral fluid flow forces from prematurely closing valve 41, as described 
above. It should also be noted that ramp 48 situated near the bottom of 
lower portion 47 of poppet valve 41 may preferably be provided in a 
substantially skeletal form to minimize negative flow characteristics 
which might be imparted by a more solid member. Particularly, it has been 
found that if ramp 48 is provided as a solid piece (as opposed to a 
skeletal or perforated member), it can sometimes catch flowing fluid and 
cause unwanted movement of poppet valve 41 prior to closure actuation. The 
resulting laminar fluid flow flows through flow passage 24 and exits into 
drop tube 28 through outlet 25b. 
As the fluid moves longitudinally through flow passage 24, some of the 
liquid is forced into suction tube 56 at its upper inlet 57. As described 
above, as fluid flows through suction 56, an underpressure is formed at 
the change of diameters therewithin, causing an effective vacuum which 
draws air inwardly through sensing tube 51, and then through connecting 
tube 66. 
As fluid continues to fill tank 10, the interior fluid level eventually 
rises to the predetermined "full" level, and reaches the lower edge 53 of 
sensing tube 51. At this point, air flow from the holding tank 12 is cut 
off, and the continuing underpressure within suction tube 56 immediately 
begins to draw air inwardly from chamber 96 behind piston 86. Air is drawn 
from chamber 96 as a result of the fluid communication provided between 
connecting tube 66 and vacuum passage 93. Removal of air from chamber 96 
likewise creates an underpressure behind piston 86, tending to pull it 
outwardly toward its actuated or extended position shown in FIG. 6. As 
best seen by comparison of FIGS. 5 and 6, as piston 86 moves outwardly in 
response to the vacuum within chamber 96, activator shaft 71 is 
reciprocated laterally in an outward direction, moving roller 72 into 
caming interaction with ramp 48 connected to valve poppet 41. The outward 
stroke of piston 86 and the interaction between the actuator elements, 
shown in this example as roller 72 and ramp 48, need only be sufficient to 
move poppet valve 41 from its substantially vertical open position, 
rotating it laterally into the fluid flow moving through flow passage 24 
(as seen in FIG. 6). Once the upper portion 47 of valve 41 is moved into 
the flow stream of incoming fluid, the fluid itself will quickly force 
poppet valve 41 downwardly into its closed position, as seen best in FIG. 
7. 
When poppet valve 41 effectively closes off the diameter of flow passage 
24, further fluid flow will be immediately stopped, and the operator of 
the filling procedures will be alerted to shut off flow at truck. When 
further fluid supply is terminated, valve poppet 41 will remain in a 
closed position due to the head of fluid which will remain in fill line 11 
thereabove. It is preferred that a predetermined amount of misfit, or 
drainage openings, be maintained between poppet valve 41 and the interior 
walls of flow passage 24, or in the poppet valve 41, so that upon 
termination of the filling procedures, the fluid head above the shut-off 
valve can slowly drain into the tank. The preferred predetermined amount 
of misfit or drainage openings allow for a leakage rate between the valve 
41 and the interior walls 24 of less than three gallons per minute. Once 
the head of fluid above the poppet valve 41 is significantly reduced by 
such drainage, the weighted nature of the poppet valve (i.e., 
counterweight 42) will automatically return valve 41 to its substantially 
vertical open condition, thus allowing quick drainage of dispensing line 
11. 
It should be noted that once piston 86 has displaced poppet valve 41 into 
the fluid flow stream (FIG. 6), it is no longer in direct physical 
connection with valve 41 (i.e., it is decoupled), and takes no further 
role in closing poppet valve 41. As mentioned above, while the actuator 
means of the present invention could be designed for direct and full time 
mechanical operation of the valve (i.e., between open and closed 
positions), it is preferred that the actuator means for closing the 
shut-off valve be decoupled for both facilitating closing and resetting 
procedures. 
It should also be noted that as soon as fluid flow through suction tube 56 
is terminated (e.g., upon closure of the shut-off valve), the 
underpressure provided by aspirator 50 will cease, the underpressure 
within chamber 96 will be eliminated, and piston 86 will automatically 
return to its normally "open" position as a result of the biasing spring 
84. Operation of the present control valve is directly determined by the 
fluid flow, and the sensitivity of the system can be maintained by proper 
design of the aspirator and actuator mechanisms to less than 1 p.s.i. 
pressure differentiations. It is also important to note that the resetting 
of piston 86 and the particular actuator roller 72, as described with 
respect to the preferred embodiments shown herein, will often take place 
while poppet valve 41 remains in closed position (i.e. during draining of 
the fill line). As mentioned above, the actuator means and the closure 
valve structure of the present invention can generally remain decoupled 
from one another except when necessary for initiating closure of the 
valve. This arrangement minimizes friction, keeps the valve structure as 
simple as possible, and enables highly sensitive shut-off reactions and 
improved automatic resetting features. Also, this arrangement eliminates 
the force required to overcome any mechanical catching means that would 
connect the poppet and the activator shaft if in a coupled arrangement. 
Having shown and described the preferred embodiments of the present 
invention in detail, it will be apparent that modifications and variations 
by one of ordinary skill in the art are possible without departing from 
the scope of the present invention defined in the appended claims. Several 
potential modifications have been mentioned and others will be apparent to 
those skilled in the art. For example, it should be understood that the 
activator shaft, roller, ramp and piston activator assembly described 
herein could be substituted by an alternate arrangement responsive to the 
underpressure changes caused by the flowing fluid herein. Similarly, 
alternative resetting mechanics could be provided for the biasing spring 
and/or the eccentric, weighted poppet design. Accordingly, the scope of 
the present invention should be considered in terms of the flowing claims 
and is understood not to be limited to the details of structure and 
operation shown and described in the specification and drawings.