Note: Descriptions are shown in the official language in which they were submitted.
WO 9S/12545 2 ~ 7 5 q 0 3 PCT/CA94/0061S
AUTOMATIC S~l'-OFF VALVE ARRANGEMENT
FIELD OF THE INVENTION
This invention relates to an automatic shut-off valve ~ for use in
fluid transfer systems. In particular, the valve Al 1. y~ or assembly may be
S mounted m a fluid tarlk or other type of fluid, zone to ~-lt~ rir:lliy shut
off flow from a source, when the desired volume of fill is reached. The assembly is
for use in automatic or semi . fluid handling systems which include
specialized nozzles and coupling systems which eliminate spillage m the process of
connection and ' of the nozzle and the tank inlet.
10 BACKGROUND OF THE INVENTION
The systems in which the present invention are employed may be generally
.1...,., r.. ;~. J as fluid transfer systems in which fluids are transferred from one zone
of ~.. l-;..,....,~ to another and in which means are required for stopping the flow
lm~ir:llly when the fluid m the du~ uc~ zone reaches some lu.
15 level.
Typically, such systems are used for I . r~ f ~ fuel from a storage vessel to
a vehicle. In the more ,..~ J systems of this type, fuel is pumped from the
storage vessel, through a flexible hose, to a nozzle which can be positively andremovably connected in a leak proof fashion to the inlet of a fuel tarlk on the vehicle.
20 Such systems are intended to prevent leakage of the transferred fuel to the
cllv;lu..l.l.llL by providing a pressure tight connection between the parts during
operation, and by erlsuring that the internal mterface between the nozzle and the tanic
iniet are effectively sealed before the noz~le can be i;~.. ~1 thus providing a
coupling with the purpose of . ' _ spillage of fuel in the process of connectionZ5 and ~' of the two
An ancillary benefit of such systems is the prevention of theft or I
diversion of fuel since flow is prevented unless the nozzle is properly cormected to a
mating vehicle tank inlet.
Automatic shut-off valves have been ill~Ul,UI ' ' in such systems, but
30 typically these are found in the nozzle. The valve is activated either by sensing a
build-up of pressure in the vehicle tank, or by the blockage of air flow under suction
from the vehicle tank back to the nozzle. There are a number of inherent
disadvantages to such I-~-i L..~ as follows.
1. Sensitive . . . - ~ are required to sense the low level changes m
3~ pressure, or suction, in an otherwise rugged ~ ilUIIIII.~IIL.
W095112545 PCT/CA94100615 o
~1 75903
2. Frequent lubrication and other preventive is required to keep
the internal ~ effectively ù~. '
3 . Wear on the nozzle c ~ is a function of the frequency of use.
When large fleets of vehicles and/or frequent refuelling operations are involved,
5 increased -lA;llt~ .. ~ can become both a nuisance and a cost factor.
4. The operator can manually control the rate of flOw which is not an
efficient method of refuelling a vehicle.
The present invention seeks to address these problems m a number of ways.
SUMMARY OF THE INVENTION
In the present invention, an automatic shut-off valve assembly is located insidea vehicle tank or other zone of ...,.l~i,. l..,1 to give the following benefits.1. Since there is a valve on each vehicle or zone of .. ,.l~;.. 1 the
frequency of use of each valve is reduced by some very c~".-: l. .,.1,1~ factor.2. Because the valve is within tne protective vl~vi~u~ L of the tarlk or zone
15 of: - t, it is less liable to suffer damage from rough or careless usage.
3. The ~ v of the assembly makes t~mpering virtually im
4. The vU~ ~Uv~iUII of the shut-off valve is such that lubrication is
U~ aly. This feature, together with a greatly reduced frequency of operation
eliminates the need for routine . ,~ P of the valve.
5. Activation of the shut-off valve to stop or prevent flow is brought about by
level sensor flow control means which preferably is ruggedly .,u..,L.u.,tvd, and most
preferably is a simple float mechanism which is not affected by variations of pressure
within the tank or zone of ~
6. The activation of the valve is a function of fluid pressure and flow rate
25 through the valve, and fluid level in the tank or zone of ~,. No m.-rh mir~l
resetting or triggering is required. The valve is either fully opened or closed.7. Changing the location of the shut-off valve from the nozzle to "tank-side"
means that the nozzle can be cul~;uv~lvly simplified and reduced in weight.
8. To r ' unusual vehicle geometry, a vehicle fuel inlet can be
30 located some distance remotely from the vehicle tank.
9. The proposed structure is casy to ~ ur~-,lul~ and install, the latter
requiring no unusual skills or expertise.
In addition to the above a.lv v . the mountmg of the shut-off valve in the
fuel tank inlet as described, allows the device the capability of handling a potentially
35 wide range of fuel flows and delivery pressure from more than one fuelling station.
For example, delivery pressures could typically range from 20-60 Ibs./sq. m. while
-
~ WO 95112545 2 1 7 5 9 0 3 PCT/CA94~00615
flow rates could typically range from 15-60 gal./mm. While it appears unlikely that
the highest flow rate would coincide with the lowest delivery pressure, it is desrrable
tbat such a condition could be - ' '
The present invention provides an automatic shut-off valve ~ for
S use in fuel transfer operations which comprises an inlet and an outlet. Means are
provided for secmring the assembly within the container such that incoming fluidpasses through it when entering the container. The - .. c,. "~ l inlet is opened and
closed in response to application of external mechanical opening means and/or
incommg fluid pressure, and the outlet is normally closed but is opened in response to
10 fluid flow through the ", . ". .~ The level sensor flow control mearls may
comprise an ancillary float actuated valve or a pilot valve or other valve means which
is actuated in response to fluid in the tank reaching a ~I~A. l..,..;.- ~i level. A bleed
passage is provided with flow restricting means in the valve A.,,.r~" .. l and is
arranged to be in ~.--",. l -';.~.. with the incoming fluid, and with the level sensor
15 flow control means from which fluid back pressure is tr~ mittP~I The bleed passage
is also in ~ .. .. ;~ -l ;. ~l. with a main valve having operating means that is located in
a main valve chamber such that fluid back pressure from the bleed passage acts upon
the operatmg means of the main valve. In this fashion, the main valve is closed as is
the main chamber, such that fluid may no longer be delivered to the tank or zone of
20 C~---'-;-..-.~ l and the valve ~ ....l is shut off.
In a preferred form, the Al~ is a valve assembly, in which there may
be provided an inlet chamber and an associated inlet valve, which controls flow to the
inlet chamber, a main chamber and an associated main valve piston operating means,
wbich controls flow to the outlet chamber from the main chamber, and an outlet
25 chamber and an associated outlet valve. In this case, the bleed passage comprises a
flow restriction section in c. with the inlet chambe}, and being in
......... ~,- ~;~.. with a volume chamber associated with the piston operating means of
the main valve.
Operation of the assembly is such that a portion of the incoming fluid passes
30 into the bleed passage when fluid flows tbrough the assembly into the container, and
out to the level serlsor flow control means, which is open when fluid in the tank or
zone of .. ~l-i.. l~ is low. When the level of fluid in the container reaches a
. .",;nr.1 level, the level sensor flow control means closes the valve and fluidback pressure through the bleed passage forces fluid through to the volume chamber
35 of the piston operating means of the main valve, whereupon the main valve closes as
the piston is displaced and fluid flow to the outlet chamber and the tank or zone of
.. ~-i....,...: is stopped and the valv~ assembly shuts off, preventing fluid flOw into
WO 95112545 PCT/CA94/00615
21 75qU3
the assembly and the container.
It should be noted that when the level sensor flow control means is open,
pressure in the du... end of the bleed passage is cllhCt~ntiAIIy lower than the
valve inlet pressure. When the static pressure in the piston volume chamber is
5 A~UII 'y equal to the valve inlet pressure, the differential area across the piston
causes it to be displaced to close the main valve.
While this description focuses on installation of the Al I A 1~ in a fuel tank
of a vehicle, it should be understood that the Al ~ or assembly may be
installed in a stationary fuel storage tank for a diesel engme, for example. Such
10 II-~ri-nc would be the type used for irrigation pumps and for emergency
generators For hospitals and the like. The vehicles may be Ll~ Ju~ iull vehicles of
all types such as buses, trucks, A.l~l...IA",. and the like, as well as off road vehicles
used in C.U...~lUUIiUII and mining, for example, earth movers and open-pit and
Lllld~ lUUlld mining vehicles. Railway equipment and marine vessels may also
15 employ the A 11 A- 1~,. ' 1'- ' ~ or assembly of this invention. The A I A I IL,~ or assembly
may also be used in any system where fluid is transferred and automatic or
semi-automatic shut off of fluid flow is required.
In a preferred form of this invention, the automatic shut-off valve assembly is
installed in a fuel tank, and the assembly comprises an inlet and an outlet. Means for
20 securing the assembly within the fuel tank are provided, as are means for commecting
the assembly to level sensor flow control means located in the fuel tank which serves
to activate the valve assembly to shut it off; the valve assembly has an inlet chamber
and an associated inlet valve, a main chamber and an associated main valve with
operating means, an outlet chamber and an associated outlet valve, and the valve~5 assembly is accessible from the tank inlet. The inlet valve is opened and closed in
respon~e to the application or removal of external mechanical opening means and/or
pressure of incomrng fluid, and the inlet chamber ~ with a bleed passage
in the valve assembly. The passage is provided with flow restricting means. The
operating means of the main valve is in ~""..,...",. ~i..., with the bleed passage, and
30 the main valve is normally open to permit fluid flow to the main chamber from the
inlet chamber, and moves to its closed position in response to fluid back pressure on
the operating means from the bleed passage. The outlet valve is normally closed, but
opens in response to fluid pressure from the main chamber. The flow path tbroughthe valve is such that during fuelling, the valves are open and permit flow into the
35 ~tank, and some flow occurs through the bleed passage to the level sensor flow control
means, which is open when the fuel level is low, and fuel flows into the fuel tank.
When the level sensor flow control means closes, upon the tank being filled to a
~ WO 9SI12545 2 1 7 5 9 0 3 PCT/CA94/00615
,Ult-'~ i-- d level, back pressure in the bleed passage causes an increase of pressure
in the volume chamber which causes the main valve to close and to stop fluid flow
into the outlet chamber, whereupon pressure on the outlet valve ceases and the outlet
valve closes. As no pressure drop then exists across the inlet valve, in the absence of
any external m-~rh~ ir~l opening mearls, the valve closes.
In the preferred ' ' the level sensor flow control mearls is usually
comnected to the end of the bleed tube by means of a flexible tube, although other
forms of comnection means could be employed. The tube may be made from any
suitable material which is flexible and fuel resistant.
The level sensor flow control means, and hence the preferred the float
actuated valve assembly may be a separate unit from the shut-off valve. It is possible
to illCul~l ' the valve within the automatic shut-off valve assembly and to place the
sensor means or float remotely or separately therefrom. It is preferably mountedclose to the top of a vehicle tank, although other suitable t~ will be
15 apparent to those skilled in the art.
The preferred means level sensor flow control consists of two essential
a valve and a float. The float may be made of cork or any other
suitably buoyant material, and will be at the bottom limit of its travel as the fluid
level in the tank rises, so that in its uppermost position it closes off the port in the
20 valve.
Gravity biases the float m its open position. It is also preferable not to secure
the flexible tubing directly to the float but rather to a lower part of a chamber which
houses the float. This seems to provide for smoother operation of the float assembly.
Usually, the float actuated valve is placed in the tank and preferably a vented
25 fuel or tank cap is secured over it. Such structures are well known in the art and
many are available commercially. Examples are those caps which are sold by GT
Du~.~v~ l."lL Corporation under the trade-mark SAFEGARD. Details of suitable
structures are found in the description of the preferred ~ I-o~
It will be apparent that many types of float actuated valve structures may be
30 used in uullllJi~liull with the shut-off valve assembly of this invention. The
I~ Uil~ i are that the device be simple in design to simplify ..,A. r- ~ ; and to
ensure reliable operation. It will also be apparent to a person skilled in the art that a
variety of means may be used to sense the fluid level including pneumatic,
".. .1,~.,;. ,.1 optical, electrical, electronic, magnetic means or devices and equivalents
35 thereof.
While in the ~Illhvdiul...l6 described it is preferred that all elements of the
valve assembly, namely the inlet and outlet valves, the main valve and the bleed
WO 95/lZ545 PCT/C~94/00615
21 75903 ~
passage with its flow restricting Al 1~ ,,. ' ' '' are all contained within the sarne
structure, it is not essential that this be the case. In its most preferred form, the
assembly does comprise the three valves and the bleed passage with its flow
restricting A- I....L,. ''.` '' Further, it is also preferred to locate the assembly at the
5 inlet of a fuel tank in which it is to be installed.
The location of the shut-off valve assembly in the fuel tank as opposed to itl
the fuel nozzle provides the advantage that the nozzle may be reduced in weight and
simplified irl design. The nozzle may now simply provide a manual shut-off valve for
the ~ " ~ fuel line. Such nozle structures are known in the art. In use, the
10 assembly of this invention is best employed with a dry-break coupling which ensures
that fluid loss is minimized or eliminated. Devices which meet these ~c~uihL~ tb are
available c~,lllll..,lc;~lly. Typical of the type of dry-break device which may be used
in ~ J- II~ 1;-1-l with the shut-off valve of the present invention is that found in U.S.
Patent No. 5,078,170 issued January 17, 199~ to Emco Wheaton, Inc., the disclosure
15 of which is hereby iII~UII)~ ' ' herein by reference. These devices are of particular
importance in the fields of application of this invention given the ~ U~JIIIII.,llkll and
cost concerns relating to fuel spillage.
In a most preferred form of the invention, the inlet valve is a poppet tube withpoppet guide means, the tube being biased in its normally closed position by suitable
20 means, such as a spring. The poppet guide includes ports for perrnitting fluid to pass
from the inlet chamber to the guide interior which is in ~,..."" ~ ,;. -li.,.. with the bleed
passage. The bleed passage is centrally located in the assembly and passes through all
chambers. While it is essential that the bleed passage ^- with the main
chamber, and with incoming fluid, it need not necessarily pass through the outlet
25 charnber and be centrally located in the assembly.
The flow restriction means preferably is in two concentric sections, a first
section which .. ".. ;. ~-t ` with the inlet and comprises a metering tube and a
metering pin which simply slows flow in the passage. The poppet guide is formed so
that it also provides a housing for the piston of the main valve, which in effect, with a
30 hollow piston interior, foTms the volume chamber. This volume chAAmber is in
...,..,.." ^ ;..., with the bleed passage, but with the second section. C.-"".--,..;. Al;(.
occurs through the annular passage which is formed between the exterior of the
metering tube and the cylindrical channel formed in the assembly. The second section
of the passage comprises a bleed tube whose end is aligned coaxially with the
35 do~llbLIcdlll end of the metering tube, but is .l;~ laterally therefrom such that
a space is formed between the two ends when a fluid back pressure situation occurs.
This back pressure forces fluid back rnto the piston volume chamber which then
Wo 95/12545 PCT/CA94/00615
~ 2 ~ 759~)3
displaces the piston amd moves the main valve to its closed position.
Alternatives to the metering pin and metering tube for controlling flow and
pressure drop through the bleed passage will be apparent to the person skilled in the
art. A typical choice would be a form srmilar to the ~ of a ~,u~ iullal
S fluid check valve. Such valves are normally used to prevent flow in one direction
while allowing free flow m the other. The active sealing member may be a ball, or
any other shape such as a conical or flat faced poppet. The flow rate, and
ly the pressure drop, through the device m the free flow direction is a
function of spring pressure. Flow regulation will result by using a spring with a
10 suitable force IIA1~ . Flow in the reverse direction is prevented by seating of
the sealing member. While this may not be necessarily 1~ lf in the present
,., I'f'~,. 1. 11 but it can be overcome by preventing the sealing member from being in
full contact with its seat.
Other methods of controlling flow and pressure drop - such as an adaptation of
15 the common needle valve or even a single very small orifice - are possible. The
present design has been selected, namely the combined metering pin and metering
tube for two principal reasorls:
- resistance to pluggmg. At the entrance to the assembly of pin and
tube, the cross section of the arlnular flow passage is effectively a
narrow but wide slot in hydraulic terms. This .. ,~;,1.. ll.1~ reduces the
potential for obstruction to flow by foreign objects in the fluid being
handled.
- simplicity in design and 1 - --r~ . By making the flow passage
between the metering pin and metering tube of sufficient length, a
larger radial clearance between the two is possible (for any specified
drop). This results in greater ease of ", - ,. .ri.. ~. ,. ;..~ to normal
production tolerances.
In operation, the following sequence occurs, this operation being described
with reference to one of the preferred forms of the invention. When the fuel tank is
30 empty or contains a small amount of fuel, the main valve is in its normally open
position. The inlet poppet valve remains in its normally shut position closing the
interior of the valve and the fuel tank to the outside. Residual fuel may remain in the
valve body but it is at the same pressure as the fuel in the fuel tank. The ou~det
poppet valve is closed precluding fluid flow from the main chamber to the outer
35 chamber. The bleed passage may contain residual fluid, but again at the same
pressure as in the remainder of the valve assembly and the tank. The float valve is
also open in this instance.
WO 95/12545 PCT/CA94/00615 ~
21 759~3
To start refuellrng, the fuel noz~le is connected to the inlet of the fuel tank,usually through a coupler which elirninates spillage in the process of connection and
.1;~. ..11--- . 1;.,., Tbe valve of the noz~le is opened and the hydrostatic head of the
supply line displaces the inlet poppet tube or the valve is manually displaced by the
S tuel no~zle or other means and fluid flows under pressure mto the valve inlet through
a fine mesh screen, if required. Fluid pressure in the inlet chamber forces fluid to
flow into the bleed passage from the inlet chamber and travels through the bleedpassage, with the flow restriction means, into the comnecting tube to tbe float valve
where the fluid flows out into the tank. Regular flow proceeds through the valve10 body with the hydrostatic pressure being sufficient to open the outlet poppet to per[nit
fluid flow from the main chamber to the outlet charnber. The function of this valve is
to mamtain a reasonably constant pressure differential between the interior of the shut-
oflf valve assembly and the discharge to the tank. The valve is not called upon to
block flow in the reverse direction and is not required to have a pressure tight seal.
15 When the fluid level in the tank rises such that the float valve is closed, flow from the
bleed passage is blocked and static pressure in the passage will increase and fluid back
pressure causes a build up of fluid in the bleed passage in the space between the first
and second flow restriction sections, such that fluid flows through the annular
clearances in the second flow restriction section back towards the volume chamber in
20 the piston, displacing the piston and closing the main valve and stopping flow from
the inlet chamber to the main chamber. With flow into the tank then stopped, thepressure on the outlet valve ceases and the valve moves to its normally closed
position. At this time there is also no pressure differential across the inlet valve,
since flow to the tank is stopped by the main valve, and so the mlet valve may return
25 to its normally closed position, unless there is some mechanical opening means
preventing it.
BRIEF DESCRIPIION OF THE DRAWINGS
Figure 1 is a Inn~ihl~in:-l cross-section of an automatic shut-off valve of the
30 present invention shown with its adapter and cap for mounting in a fuel tank inlet, the
upper and lower halves of the Figure show the valve in open and closed positions,
Figure 2 is a cross-section of a float valve shown mounted in a fuel tank;
Figure 3 is a cross-section of an alternative float valve shown mounted in a
35 fuel tank;
Figure 4 is an alternative, .,.1"~,1;"....: to the valve of Figure 1 shown in
Inn~ih-~lin:ll cross-section;
~ WO9S/12545 2 1 7 5 9 0 3 PCT/CA94/00615
Figure 5 is a cross-section through Figure 6 along Ime 5-5, through the piston
area;
Figure 6 is an enlarged I ,, ' I partial section showmg flow passages
through the valve assembly shown in Figure 1;
5 Figure 7 is a 1.,.. ~ cross-section of a piston used in the valve of Figure l;
Figure 8 is a side Yiew of a piston used in the valve of Figure 1;
Figure 9 is a hransverse cross-section of an outlet poppet retainer in the valveof Figure 1;
Figure 10 is a top view of the outlet poppet retainer as shown m Figure 9;
Figure 11 is a l-- ,~ illAI section of an inlet poppet guide in the valve of
Figure 1;
Figure 12 is an end view of the inlet poppet guide of Figure 11;
Figure 13 is a side view of the inlet poppet guide of Figure 12;
Figure 14 is a schematic showing a fluid hransfer assembly which includes a
nozzle, a dry-break coupler, a valve assembly according to the mvention mounted in a
fuel container and a float achlated valve;
Figure 15 is an alternative ~ ...1,o.1;.~.. .l of the valve assembly of the present
invention, shown in ~ - li. -l cross-section;
Figure 16 is a check valve which may be used in place of a metering pin and a
metering hube illustrated in the previous figures.
DESCRlPTION OF TEIE PREFERRED EMBODIMENTS
Referring now to Figure 1 of the drawings, there can be seen a Inn~ihl~ir-~l
cross-section of an automatic shut-off valve assembly designated generally at 1. The
25 flow passages m valve assembly l are further illustrated in Figures 5 and 6 and
reference should be made to these figures as needed throughout this dl~srrirtinn The
upper and lower halves of Figure 1 illustrate the valve assembly 1 in open and closed
positions, Ic~ ly, and Figure 6 shows it in an open position. The valve
assembly 1 comprises a valve body 10, typically made from drawn steel ~hubing, which
30 is provided at its inlet, generally indicated at 11, for mounting the valve m a fuel tank
inlet (not shown) with an inlet adapter 12 and an adapter nut 14, each usually made of
- bronze. The tank inlet is closed with the valve assembly 1 which includes a dust cap
16, generally of steel provided with usual tension means, in this case spring 17, for
ensuring tbat it remains securely shut when closed. Adapter nut 14 is secured to the
35 tank by means of screw threading shown at 18. Valve body 10 includes an inletchamber 20, a main chamber 22 and an outlet chamber 24. Inlet chamber 20 houses
WO 95/12~45 ` PCTICA94/0061~ ~
21 1S903 lo
an inlet poppet tube 26 which is normally biased, by suitable means, such as a spring
29 (usually a helical, , steel spring) as shown herein, in its closed position.
Inlet poppet tube 26 serves to close and seal the inlet 11 of the shut-off valveassembly 1 and the fuel tank (not shown) in which it is located. Inlet poppet tube 26
5 is provided with sealing means 32, which preferably comprises an annular rl: 1, ,..", ;,,
seal of a material which is fuel resistant, around its end to ensure that it seats against
the inlet adapter, which is shaped to receive the seal 32 to seal the inlet as required in
ruch incl~ll .tjnnc
The pressure in the biasing means 29, usually a spring, and in this case a
10 helical CU~ C~;U~ steel spring, is l,.~ l such that upon application of
pressure via a fuelling nozle (not shown) and fuel being delivered under pressure, the
poppet 26 will be displaced along its In ~ axis to permit entry of fluid into the
inlet chamber 20. The fluid flow path through the valve when entering the tank is
marked with arrows which bear the letter A in Figures 1 and 6. Arrows B show fluid
15 flow through bleed passage 46 and back pressure flow is shown by arrows C. When
poppet tube 26 is displaced away from the inlet opening, it is guided along inlet
poppet valve guide 28. The lengths of the poppet tube 26 and valve guide 28 are
selected such that ports 30 located in the inlet poppet valve guide remain exposed and
thus fluid may flow from inlet chamber 20 to the interior of inlet poppet valve guide
20 28, which is hollow and ~(,.. ~ .; ~ ~ with a bleed passage designated generally at
46. The inlet poppet tube 26 and inlet poppet valve guide 28 are sized such that each
slides smoothly, one over the otber and necessarily; the inlet poppet tube is hollow for
this purpose.
An end portion 36 of the inlet poppet valve guide acts as a piston chamber for
25 piston 38 and valve 41. It also provides an entrance for bleed tube 66. The entrance
is provided by virtue of a circular aperture 46a (see Figures 11, 12 and 13) andcylindrical extension 46b thereof, which extends in the direction away from the
poppet guide 28. The size of this aper~ure 46a is such that it receives a metering tube
42 which is sized to receive a metering pin 44 in a wedge-like fashion. Metering tube
30 42, pin 44 and aper~re 46a and bleed tube 66 are selected such that annular
clearances are provided between one and the other in order for fluid to pass between
all surfaces. The metering tube 42 and pin 44 comprise the first section oF the flow
restricting means. It should be noted that a multiple number of ports 30 is provided
in inlet poppet valve guide 28 to provide good and adequate fluid flow
35 into the bleed passage 46 while fluid is entering the fuel tank, as will be described in
detail later. All interior valve parts are usually made of fuel resistant plastic such as
materials sold under the trade-marks DELRIN and CELCON. The metering pin 44 is
~ WO 9S112S45 2 1 7 5 q ~ 3 PCT/CA94/0061S
typically stainless steel and the metering tube is usually drawn stainless steel.
The piston 38 includes a volume chamber 40 for receiving fluid from the bleed
tube 66. As indicated, piston 38 is guided and retained within piston housing orchamber 36 which is formed m the end portion of inlet poppet valve guide 28. The5 piston 38 is secured to the bleed tube 66 at region 56. Main valve 41 is normally
biased by means of a spring 52, which in this instance is a conical, helical
, ~ spring, in an open position which permits flow of fluid from inlet
chamber 20 to main chamber 22. Seals 48 are provided at upper and lower regions of
the piston 38 to permit the piston 38 either to seal off the valve assembly I with
10 respect to flow between chambers 20 and æ or to move freely therein. The piston 38
includes a narrower diameter portion 38a and in this area there is provided an
enlarged annular area 56 for fluid passage to the piston volume chamber 40. It is in
this area or region 56 that the piston 38 is secured to bleed tube extension 64, which
surrounds metering tube 42 creating a channel or annular passage 42a which leads15 into volume chamber 40. The adjacent portion of the bleed tube 66 extends to and
through outlet 13 of valve body 10. Bleed tube 66 is secured to the interior of piston
38, at its left hand end, such that it is displaced therewith. A space 68 is provided
between bleed tube portion 66 and the end of metering tube 42. Poppet 62 is
provided with a central cylindrical bore 62a for receiving metering tube 42 and bleed
20 tube 66. Poppet 62 slides ;~ ly over bleed tube 66. When a fluid back
pressure situation occurs in the bleed passage 46, fluid ~ in space 68 and as
pressure increases, back pressure results in fluid building in volume chamber 40which then displaces piston 38 which closes main valve 41. Normally, outlet poppet
62 is biased, in this case by means of a spring 63, in a closed position. The function
25 of this outlet poppet 62 is to maintain a reasonably constant pressure differential
between the mterior of the shut-off valve assembly and the discharge to the tank. The
poppet 62 is not called upon to block flow m the reverse direction and is not required
to have a pressure tight seal.
It will be noted that general valve seat 49 includes valve seat portion 50 for
30 receiving seal 48 of valve 41. The material of valve seat 49 is selected such that the
inteRace between the head of poppet 62, which in this case is a conical shape forms a
seal with valve seat 54.
Many float actuated valve structures are known and any design may be
employed as long as it will function in the ~ t, usually a fuel tank of a
35 vehicle which must perform in all types of weather. It must be fuel resistant and
must be simple for ease of .I.~.llur~.L.I.c and reliability.
Referring now to Figures 2 and 3, there are shown two alternative designs for
WO 95112545 PCT/CA94/00615 ~
2 1 75903 12
float actuated valves which may be used with the valve assembly. Referring first to
Figure 2, there is shown generally at 100, a float actuated valve. The valve lO0 is
located at a vented outlet 110 in a fuel tank 103. The valve is secured to a capassembly 101 by means of a bolt 105. The cap may also be installed by simply
S bolting it to a top portion of fuel tank 103 without use of this cap assembly 101. The
cap assembly 101 may be selected from any of those available I ~.;ally which
provide high capacity pressure venting, bulk fluid ~.Il,U.,l~Lu-~ sensitive thermal
venting and anti-spill breather venting. It will be apparent that the use of the cap
assembly 101 provides ready access to the float actuated valve 100, for installation
10 amd ,. ~ . Float 102 may be made of cork or other buoyant substance which
is fuel resistant, and is located in valve chamber 108 which is sized to receive the
float 102 to move freely up and down in the chamber 108. Tube 109 which connectsto a bleed passage in a valve assembly as shown in Figure 1, extends through thecentre of float 102 so that when float 102 rises as a result of fuel entering bottom
15 openmg 104 in valve chamber 108, the top 107 of tube 109 contacts base 106 of the
bolt 105 to seal off the bleed passage.
In Figure 3, the float actuated valve, designated generally at 200 has a very
similar structure to that shown in Figure 2. Thus float 202 is housed within float
chamber 208 which has side openings 204 which permit fluid to enter and move the20 float upwardly. Rather than tube 209 being directly connected to the float, a float
extension 210 and float extension chamber 210a are provided, to which tube 209 is
secured. Shoulders 211 of float extension 210 rest against seats 212 in the upper part
of chamber 210a to seal off the bleed passage, when the float 202 rises upwardly.
Referring now to Figure 4 of the drawings, the upper half of the drawing
25 shows a shut-off valve, designated generally at 2, in open position and the lower half
illustrates valve 2 in closed position.
The design of this valve is substantially the same as the shut-off valve as
shown in Figure 1, with the exception that the inlet poppet 326 is of an alternative
uullaLru,liull. In this uul~LIu~_Liul~, inlet poppet 326 is a solid body of cylindrical
30 shape sized to reciprocally slide within inlet poppet guide 328. Spring 329 biases the
inlet poppet 326 m its closed position. The inlet end 327 of the poppet 326 is
enlarged relative to its main body portion 325 to provide a closure for the valve 2 and
the tank inlet (not shown) when mounted therein. The top of spring 329 rests against
a nange 327a on end 327 of poppet 326. The other side of this nange 327a provides
35 a recess 332a for a seal 332. Ports 330 are provided in poppet guide 328 to allow
passage of fluid from inlet channel 320 into a bleed passage designated generally at
346. Piston 338 is also of a slightly different shape at its open end and the
WO95/12~54!i 2 ~ 7 ~ 9 0 3 PCTICA94100615
13
for locating seal 348a which is of a different shape is necessarily altered.
All other parts of the structure are the same as for the assernbly of Figure 1. In this
instarlce, tbe parts have been labelled and the r~nnbers correspond except for th~ digit
3 used for the assembly of Figure 4.
S Figures 7 and 8 illustrate a ' ,, " i cross-section and a side view of piston
38 as found in valve I of Figure 1. Piston 38 is generally cylin~irical in shape and
has an u~ e. d~ cavity 40 which acts as a volume chaunber during operation of the
shut-off valve. Portion 38a is narrower in e~terior diameter and receive and secures
bleed tnbe 66. Upper exterior flariges 48b and 48c proYide a recess for receiving an
10 annular seal 48. Anotber u.~ flange 48a is provided at a point just before the
piston narrows to provide a recess for another annular seal 48 which seats piston 38
upon piston seat 50 providing a seal between chambers 20 and æ. Spring 52 rests at
52a which is the top of what could be called the neck of the piston.
Figures 9 and 10 illustrate a diametrical section through poppet outlet retainer15 70 and a top view thereof, l.,*.~Li~;y. The retainer 70 has a central aperture 72
which is sized to receive bleed tube 66 and is provided with a . ;. ,,. .. F ' ~:_1 flange
73 which provides a stop for outlet poppet 62, retaining it in place within valve body
10. Sprmg 63 rests on either side of flange 73. Apertures 71 are provided in poppet
outlet retamer 70 which in this instance are tbree, and elongate in shape to allow flow
20 out of the shut-off valve assembly l into the tank (not shown). It will be apparent
tbat bleed tube 66 when placed within aperture 72 provides a guide or path of travel
for outlet poppet 62.
Figures 11, 12 and 13 illustrate the inlet poppet valve guide 28 found in valve
1 of Figure 1. Guide 28 is generally an ~ll e~ cylinder. Narrower portion 28a
25 is sized so that poppet inlet tube 26 slides easily back and forth thereover. Its length
is such tbat tube 26 when ful)y open does not cover ports 30 which permit passage of
fluid into bleed passage 46. A flanged central aperture 46a (flange 46b~ provides
entrance to bleed passage 46. It is sized to receive metering tube 42 which receives
metering pin 44 as previously described. Tube 42 is secured in the aperture 46a such
30 that fluid flow may not occur Ih~lel,~ . An end portion 36 of guide 28 forms
piston housing or chamber 36 which is sized to slidingly engage and receive within,
piston 38, which surrounds bleed tube 66. On the exterior of end portion 36 are a
series of, in this case three, rectangular vanes which are sized to allow guide 28 to
rest within valve body 10 so that guide 28 lies adjacent top edge 49a of general valve
35 seat 49. This structure permits flow through valve body 10 and ensures that inlet
poppet guide 28 is maintained in an axially aligned position, within valve body 10.
The ends of lower portion 36 of guide 28 provide a stop for piston when it is in open
WO 9S/12545 PCTICA94/00615
2~ 759a3 14
position.
In Figure 14 of the drawmgs, there is shown in schematic fashion an assembly
for ~ r .; ~ fluids designated generally at 400. A fuel noz~le 401 of known
,. ",~l ... l i- -.. is secured to an inlet 406 of a fuel tank 408, through a dry-break coupler
S 402 of known ~ ,- The dry-break coupler 402 is secured to inlet 406 after
cap 407 is opened. To mlet 406, there is secured an automatic shut-off valve
assembly 403 as already described. Valve assembly 403 is connected via flexible
tubmg 405 to a float actuated valve 404 located at the top of fuel tank 408. In this
instance, valve 404 is secured by means of a bolt 404a rather than with a special
10 venting cap as described earlier.
In Figure lS, there is shown an alternative structure for the automatic shut-offvalve assembly of the present inverltion. In this structure, there is provided a valve
assembly designated generally at 500, having an inlet 501 and an outlet 502.
The inlet 501 leads into inlet chamber 527 which ~ with a bleed
IS passage 503 which includes a metering pin 504 which thus provides flow restriction to
a bleed passage chamber 505 from which leads to a bleed passage outlet 506 to which
is secured a flexible tubing 508. Tubing 508 is secured to the outlet 506 by means of
securing means 507, and leads to a level sensor flow control means or valve or
preferably a float actuated valve as deæribed previously but is not shown here. The
20 inlet chamber 527 leads to a main chamber 528 and flow Lh.,le~ is controlled
by a main valve 530. The main part of valve body 520 has an end piece 525 open to
internal atmosphere of tbe tank and a lower closing space S09. The main valve 530
may be considered as a single functioning entity in which a spool 515 travels axially.
The valve body SZ0 internal diameter is larger at one end than the other, and at the
25 larger end the spool SlS il.~u,l a piston S11 which carries on its outer diameter
a low friction ~ type seal 513. The seal 513, m turn, slides m the bore
520a of the valve body SA~0.
Near the centre of the valve body 520, an inturned flange 540 is shaped to
form a seat 540a for a face seal 514, preferably a quad seal, which is secured to the
3û back of the piston S11, so that when the latter is driven towards the seal seat 540a,
either by spring (S10) pressure or hydrostatic pressure on the piston face SlOa, the
sealing action prevents fluid flow through the body of the valve, i.e. into mainchamber 528.
At the other, smaller diameter, end of the valve body 520, a c(",~ lly
35 available rolling diaphragm 521 is attached to the end of the spool SlS to form a
"zero friction" seal and to centre the spool SlS in the bore 520a. This A.l~l~L" .11. .
effectively contains the fluid within the body of the shut-off valve assembly 500 at
WO95/lZ545 2 1 7 5 9 a 3 PCT/CA94/00615
this end while allowing free movement of the spool 515 in reaction to the pressure
and force vir~l~ ' which may exist in the valve body 520.
An outlet poppet valve 560 receives the fluid flow from vhe outlet port 502 of
the shut-off valve assembly 500 and discharges it into the tank (not shown), either
S directly or through a diffusion conduit of some kind (not shown). The function of
this valve is to maintain a reasonably constant pressure differential between the
interior of the shut-off valve assembly 500 and the discharge to the tank (not shown).
In its ~u.~.lu~Livll, it resembles a ~VII~ iVllal check valve with a spring (518) loaded
poppet 517 and guide 519 which can be displaced by upsvream fluid pressure.
10 However it is not called upon to block flow in the reverse direction and is not
required to have a pressure tight seat.
The shape and dimensions of the flOw path through the outlet poppet valve 560
and vhe spring 518 are chosen so vhat at the lowest expected flow rate, the poppet 517
will be displaced a small amount to provide a narrow armular orifice with a
15 pre-determined pressure drop. Whatever static pressure is developed at vhe poppet
face due to this pressure drop will be balanced by vhe force of the spring 518 to bring
the forces into ~.l.,;l;l"; ~
It will be noted that the internal diameter of the outlet poppet valve body 560
increases in vhe direction of flow so that the further the poppet 517 is displaced, the
20 greater the cross-sectional area of the annular orifice (and c~ l" /ly the lower the
pressure drop at any fixed flow rate). As a result, if the flow rate should be higher,
up to the maximum expected, the initial high pressure drop across the poppet 517 will
cause a greater ~ of the latter until the forces are again in balance. Since
the reactive force of the spring 518 under this condition would obviously be greater
25 than under the low flow condition, a somewhat higher pressure drop would result. By
judicious selection of the spring 518 rate and its 1' , the difference in
pressure drop between high and low flow conditions can be held to a few pounds per
square inch.
Operation of the valve assembly of this c ' ' is in principle very
30 similar to the operation of the earlier described structures. However, this description
will highlight the particular differences.
Starting from a condition in which the vehicle tank fluid level is low, the mainvalve assembly 520 will be empty or will contain residual fluid at the same pressure
as the fuel tank interior (not shown), the shut-off valve 520 will be held by spring
35 (510) pressure in its closed position; the outlet poppet valve (560) will be in its closed
position; and a tank inlet adapter poppet (not shown) will be closed, creating a seal
between the tank interior and the ell~ill An associated float actuated valve will
WO 9~/12545 PCT/CA94/00615 ~
21 75qO3 16
be open at this point.
To start refuelling, a nozzle will be connected to the inlet adapter which
hlCu~ means to eliminate spillage (not shown) and the nozzle manual shut-off
valve (not shown) opened. This will allow the hydrostatic head of the supply line to
5 displace the inlet adapter poppet, and the fluid to flow under pressure into the valve
inlet section or chamber 527 (through a fine mesh screen if necessary).
The pressure in the valve inlet chamber 527 will cause a small flow of tbe
fluid through the bleed passage 503 mto the bleed passage chamber 505 of the
shut-off valve body 520 and thence, by way of the tubing 508, to be discharged
10 through valve openings into the tank. The dimensions and C~ liyl~ of the bleed
passage 503 are such that there will be a high pressure drop between the valve inlet
section and the end cavity of the shut-off valve body. The shape and dimensions of
metering pin 504 is selected d~,uld-l-~;ly to provide .I~)~JIU,U ' ' flow rates.(~.,.. ~.. 1.. lly the fluid pressure in tbe cavity will be of a low order.A differential pressure will appear across the piston S11, of sufficient
maglutude to compress the spring SlO and cause the spool assembly SlS to move toopen the shut-off valve 530 and thus perrnit fluid flow into the du .. ~L~ chamber
528 of the shut-off valve body and thence the outlet poppet valve 560 into the tank.
As e~plained above, the pressure drop across the outlet poppet valve 560 wi
20 create a back pressure in the shut-off valve body 520 and this will serve to hold the
shut-off valve spool 515 in the open position against the spring 510.
When the tank fluid level rises sufFIciently to cause the float to close its
associated valve, flow from the shut-off valve cavity 528 will be blocked and static
preSsure in the cavity will increase due to its commection through the bleed passage
25 with the valve inlet chamber 527. Eventually, the cavity pressure will be of the same
order as that in the main chamber 528 of the shut-off valve 530. Because of the
differential areas of the piston faces and the spring 510 pressure, the forces acting on
the spool 515 will be unbalanced causimg the spool 515 to move to close the shut-off
valve 530.
With no flow through the shut-off valve 530 or the level sensor flow control
means or valve or float valve (not shown), there will be no pressure drop across the
tank inlet adapter and its spring will move the poppet into the closed position.Closing the manual nozzle valve would have the same effect. None of these
structures are shown. With the manual nozzle valve closed, the nozzle can be
35 .1i~.. ,.. ~.1 from the tank inlet adapter with a dry break.
Referring to Figure 16 of the drawmgs there is illustrated a greatly enlarged
view in lon~ihuiin~l cross section of check valve which may be used in place of the
WO 9S/12545 2 1 7 5 9 0 3 PCT/CA9410061S
.
17
metering pin and metering tube described earlier. Valve housing 600 has openrngs604 and 605, which are an outlet and an rnlet, ~ ,ly. The outlet 604 is closed
by means of ball 602 which is held closed normally by spring 601. The valve
housing would be placed in a similar location to the metering tube 42 and metering
S pin 44 as described earlier.
It will be apparent from readrng this description of preferred ,lllbU '' ' tbatmany ...~ - or alterations may be made without departing from the spirit and
scope of the invention as defned irl the following claims, which are meant also to
encompass all equivalent forms of the invention as would be apparent to a person10 skilled in the art.
