Note: Descriptions are shown in the official language in which they were submitted.
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GAS FLOW REGULATION SYSTEM
FIELD OF INVENTION
The present invention relates to gas flow regulation systems for
controlling the flow of gas, and more particularly relates to tank-mounted
modules for controlling the flow of high pressure gaseous fuels such as
compressed or liquified natural gas or hydrogen from a storage tank.
BACKGROUND OF THE INVENTION
It is becoming increasingly common to use so-called alternative fuels,
such as propane or natural gas, in internal combustion engines or hydrogen in
fuel
cells. Often such engines are converted to use one or two or more sources of
fuel,
such as gasoline and natural gas. The operator has the ability to switch
between
sources depending on the availability and price of these fuels.
Many vehicles are manufactured to operate on gasoline only and are
converted to run on two or more fuels. The vehicles are manufactured with
storage tanks for gasoline, pumps for moving the gasoline from the tank to the
engine, and carburetors or fuel injectors for introducing the fuel and the
required
amount of air for combustion into the engine.
Gaseous fuels such as propane, natural gas, and hydrogen must be stored
in pressurized cylinders to compress the gas into a manageable volume.
Increasing the pressure to the highest level that can safely be handled by the
pressurized storage cylinder increases the amount of fuel that can be stored
in that
cylinder and extends the distance that the velucle can be driven to its
maximum.
Typical storage cylinder pressures range from 2000 to 5000 prig.
Internal combustion engines cannot operate at such a high pressure, and
the pressure of the gas must be reduced to a level at which the engine can be
operated safely.
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The pressure must also be regulated as it is reduced to ensure that the
pressure of the fuel entering the engine is nearly constant even as the
pressure in
the storage cylinder is reduced. At the same time, the pressure regulation
must
permit as much gas as possible to be removed from the storage cylinder, and
thus
permit the pressure in the storage cylinder to fall to as close to the
operating
pressure as possible. A high pressure difference across the pressure regulator
means that unused fuel remains in the storage cylinder and is unavailable to
the
engine.
Conventional pressure regulators having one or more stages over which
the pressure is reduced are well-known and have long been used to reduce the
pressure and regulate the flow of compressed gases. Some of these are known as
pressure-balanced regulators and use various arrangements of springs,
diaphragms and machined parts to balance pressures and fluid flow over the
various stages of the regulator.
One major concern is the vulnerability of flow components carrying
alternate fuels, including pressure regulators, to crash damage. If the
vehicle is
involved in an accident, such components must not fail in an unsafe or
catastrophic manner. To this end, internally-mounted pressure regulators have
been designed to mitigate such unsafe or catastrophic conditions. An example
of
such pressure regulators is disclosed in Sirosh et al., U.S. Patent 6,041,762.
Although Sirosh's pressure regulator can be internally mounted within a
single nozzle in a storage cylinder, the space occupied by such regulator
prevents,
as a practical matter, the further internal mounting of a solenoid shut off
valve
within the same nozzle to open and close flow to the pressure regulator or the
further internal mounting of a second regulator stage. The size of the nozzle
could be increased to accommodate the solenoid shut off valve or a second
regulator stage. However, such design changes would reduce the pressure rating
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of the associated storage cylinder, thereby preventing its use in storing high
pressure gases.
SLT.~IARY OF THE INVENTION
In a broad aspect, the present invention provides a gas flow regulation
module comprising a module housing, including a longitudinal axis, and
including a first port and a second port, a first fluid passage extending from
the
first port, and a second fluid passage extending from the second port; and a
regulator, mounted to the body and disposed in communication with the first
and
second fluid passages, including a moveable pressure boundary member
characterized by a transverse axis which is transverse to the longitudinal
axis of
the module housing.
In a further aspect, the present invention provides a gas flow regulation
module comprising a module housing, including a longitudinal axis, a first
port
and a second port, a first fluid passage extending from the first port, and a
second
fluid passage extending from the second port and a regulator, mounted to the
body and disposed in communication with the first and second fluid passages,
including a moveable pressure boundary member substantially disposed in a
plane
which is substantially parallel to the longitudinal axis of the module
housing.
In yet a further aspect, the present invention provides a gas flow
regulation module, adapted for mounting within a pressure vessel and through a
nozzle provided in the pressure vessel, the pressure vessel including an
interior,
the nozzle including a longitudinal axis, comprising a module housing,
including
a first port and a second port, a first fluid passage extending from the first
port
and a second fluid passage extending from the second port and a regulator
mounted to the body and disposed in the interior of the pressure vessel and in
communication with the first and second fluid passages, including a moveable
pressure boundary member characterized by a transverse axis which is
perpendicular to the longitudinal axis of the nozzle.
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In yet another aspect, the present invention provides a gas flow regulator
module, configured for mounting within a pressure vessel, and through a nozzle
provided in the pressure vessel, the pressure vessel including an interior,
the
nozzle including a longitudinal axis, comprising a module housing, including a
first and a second port, a first fluid passage extending from the first port,
and a
second fluid passage extending from the second port and a regulator mounted to
the body and disposed in the interior of the pressure vessel and in
communication
with the first and second fluid passages, the regulator including a moveable
pressure boundary member substantially disposed in a plane which is
substantially parallel to the longitudinal axis of the nozzle.
In yet another aspect, the present invention provides a gas flow regulation
module comprising an elongated body including a longitudinal axis, a fluid
passage disposed within the body, a valve seat disposed within the fluid
passage,
IS an orifice disposed within the valve seat, a valve, configured to seal the
orifice,
and a moveable pressure boundary member, coupled to the valve, and
characterized by a transverse axis which is transverse to the longitudinal
axis of
the body.
In yet a further aspect, the present invention provides a gas flow
regulation module, configured for mounting within apressure vessel, and
through
a nozzle provided in the pressure vessel, the nozzle including a longitudinal
axis,
comprising an elongated body, a fluid passage disposed within the body a valve
seat disposed within the fluid passage, an orifice formed within the valve
seat, a
valve, configured to seal the orifice, and a moveable pressure boundary
member,
coupled to the valve, and characterized by a transverse axis which is
transverse
to the longitudinal axis of the nozzle.
In yet a further aspect, the present invention provides a gas flow
regulationmodule,configuredformountingwithinapressurevessel,andthrough
a nozzle provided in the pressure vessel, the nozzle including a f rst
diameter,
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comprising a fluid passage, a valve seat disposed within the fluid passage, an
orifice formed in the valve seat, a valve configured to seal the orifice, and
a
moveable pressure boundary member, coupled to the valve, including a second
diameter which is greater than the first diameter.
In yet a further aspect, the present invention provides a gas flow
regulation module, configured for mounting within a pressure vessel, and
through
a nozzle provided in the pressure vessel, the nozzle including a longitudinal
axis,
comprising a fluid passage, a valve seat disposed within the fluid passage, an
orifice formed in the valve seat, a valve configured to seal the orifice, and
a
moveable pressure boundary member, coupled to the valve, and substantially
disposed in a plane which is substantially parallel to the longitudinal axis
of the
nozzle, wherein the moveable pressure boundary member is configured for
insertion through the nozzle.
By orienting the moveable pressure boundary of the regulator in this
manner, the module can further include a solenoid shut-off valve or a second
regulator stage without requiring large nozzles to fit such an assembly in the
interior of a pressure vessel.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set
forth above will become apparent when consideration is given to the following
detailed description thereof. Such description makes reference to the annexed
drawings wherein:
Figure 1 is a side elevation view of an embodiment of the present
invention;
30_ Figure 2 is a top plan view of the embodiment of the present invention
illustrated in Figure 1;
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Figure 3 is a sectional elevation view of a regulator of the embodiment
of the present invention illustrated in Figure l;
Figure 4 is a cut-away sectional elevation view of the pressure regulator
in Figure 3, showing components in the vicinity of the convolution of the
diaphragm;
Figure 5 is a sectional elevation view of the embodiment of the present
invention illustrated in Figure 1;
Figure 6 is a cut-away sectional elevation view of the regulator in Figure
5, showing each of the individual stages of the regulator;
Figure 7 is a second sectional elevation view of the embodiment of the
present invention illustrated in Figure 1;
Figure 8 is a sectional elevation view of the solenoid shut-off valve of an
embodiment of the present invention, showing the solenoid shut-off valve in a
closed position;
Figure 9 is a sectional elevation view of the solenoid shut-off valve of an
embodiment of the present invention, showing the shut-off valve in a
transition
position;
Figure 10 is a sectional elevation view of the solenoid shut-off valve of
an embodiment of the present invention, showing the shut-off valve in an open
position;
Figure 11 is a schematic showing the flow path taken through a shut-off
valve of an embodiment of the present invention during filling of a pressure
vessel with a gaseous mixture;
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Figure 12 is a schematic drawing showingmanual shut-offvalveblocking
floor between a solenoid shut-off valve and a regulator of an embodiment of
the
present invention;
Figure 13 is a sectional plan view of the embodiment of the present
invention illustrated in Figure 1; and
Figure 14 is a schematic illustration of the process flow paths provided
in an embodiment of the present invention.
DETAILED DESCRIPTION
Figure 1 illustrates an embodiment of a gas flow regulation module (2)
of the present invention. Module (2) comprises a body (3) including a head (4)
and an elongated neck (6) extending therefrom. Pressure regulators (10) and
(110), and solenoid shut off valve (210) are formed within neck (6) to control
flow of gas from a pressure vessel (216). In this respect, module (2)
functions as
ahousing forpressure regulators (10) and (110) and solenoid shut offvalve
(210).
Referring to Figures 3 and 4, pressure regulator (10) includes spring
housing (12) mounted to base (14) to form regulator housing (16). Housing (16)
includes an inlet port (18) communicating with a pintle chamber (20). Pintle
chamber (20) communicates with output chamber (22) and includes a valve seat
(23) with orifice (24). Valve pintle (26) is disposed within pintle chamber
(20)
and includes sealing surface (28) to press against valve seat (23) and thereby
close orifice (24). Output chamber (22) communicates with outlet port (25)
formed within housing (16) (see Figure 5).
Valve pintle (26) is movable to open and close orifice (24) in response to
the combined action of spring (30) and moveable pressure boundary member
(31). Spring (30) is provided within housing (16) to exert a force which tends
to
move the valve pintle (26) towards an open position wherein sealing surface
(28)
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is unseated from valve seat (23), thereby opening orifice (24) into
communication
with output chamber (22). Gas pressure in pintle chamber (20) and output
chamber (22) acts against moveable pressure boundary member (31) and valve
pintle (26) thereby opposing forces exerted by spring (30) and tending to move
valve pintle (26) towards a closed position, wherein sealing surface (28) is
pressed against valve seat (23), thereby closing orifice (24). Pintle stem
(34)
extends from valve pintle (26), terminating in pintle nut (36). Pintle nut
(36) is
mounted within central boss (38). Central boss (38) extends through the centre
of moveable pressure boundary (31). A locking ring (44) fits over central boss
(38) and bears down upon moveable pressure boundary member (31).
Spring (30) is fitted over locking ring (44), and is supported on moveable
pressure boundarymember (42). Spring (30) is retained within a spring chamber
(46) formed within housing (16). Spring (30) can include coil springs, spring
washers, or elastomeric-type springs.
In one embodiment, moveable pressure boundary member is a diaphragm
assembly comprising a diaphragm (32), first diaphragm plate (40) and diaphragm
support plate (42). Diaphragm (32) is mounted on a first diaphragm plate (40)
disposed on one side of diaphragm (32) and extending from central boss (38).
The diaphragm (32) is retained on the first diaphragm plate (40) by means of a
diaphragm support plate (42) and a locking ring (44). As such, diaphragm (32)
is interposed and pinched between first diaphragm plate (40) and diaphragm
support plate (42). Groove (48) is formed within housing (16) to receive
diaphragm (32), thereby securing diaphragm (32) to housing (16). In this
respect,
diaphragm (32) seals output chamber (22) from spring chamber (46), thereby
isolating output chamber (22) from spring chamber (46). Diaphragm (32) is
generally characterized by a flat profile. Diaphragm (32) includes a first
side
surface (56) and second side surface (58) (see Figure 4). First side surface
(56)
is exposed to gas within output chamber (22). Diaphragm (32) further includes
a throughbore (60) which receives central boss (38). In one embodiment,
_g_
CA 02414233 2002-12-24
diaphragm (32) includes a rolling convolution (50) extending from a section
(52)
characterized by a flat profile, to provide a modification in the behaviour of
,
diaphragm (32). Specifically, this design attempts to ensure that diaphragm
(32)
is always in tension i.e. never in shear or compression). =Thus, as the
convolution rolls, diaphragm (32) is never stretched or buckled i.e., largely
eliminating hysteresis).
Pressure regulator (10) is characterized by an orientation wherein the
transverse axis (61) bf moveable pressure boundary member (31) is transverse
to the longitudinal axis (62) of neck (6) (see Figure 1). In one embodiment,
the
transverse axis (61) is perpendicular to the longitudinal axis (62) of neck
(6). As
a further incident, moveable pressure boundary member (31) lies or is disposed
substantiallyin a plane which is substantiallyparallel to the longitudinal
axis (62}
of neck (6). Such orientation permits the insertion of module (2) , including
a
regulator, with a relatively larger diameter moveable pressure boundary member
(31), into a small diameter nozzle (217) of a pressure vessel (216) (see
Figures
1, 5 and 7). , . . ... . ' _
.In another embodiment, moveable pressure boundary (31 ) is characterized ' ~
'
by a diameter which is larger than the diameter of nozzle (217). Furkher, in
yet
another embodiment, moveable pressure boundary (31) is characterized by a
maximum diameter which is larger than the diameter of nozzle (217). In either
'case, byvirtue of the orientation of the moveable pressure boundary (31)
relative .
. to nozzle '(217}, module (2} is configured for insertion -into' nozzle-
(217): '- Inr'
particular, moveable pressure boundary (31 ), by virtue of its orientation, is
configured for insertion through the nozzle by virtue of its orientation, and
notwithstanding its dimensions relative to the nozzle {217).
Use of larger diameter moveable pressure boundary members (31} in
pressure regulators is desirable so that the pressure boundary member is more
sensitive to pressure changes in the output chamber (22), thereby providing a
. .1~ ~ ~-~ ~1~ ,':w~~ _ y. ~ ' ~ y . 08 1 D-20C
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more accurate response to these pressure changes and mitigating droop. Because
moveable pressure boundary member (31) is oriented in this fashion, more space
is available within module (2) for the formation of various flow passages
necessary for permitting internal mounting of a solenoid shut-off valve (210)
in
conjunction with a regulator.
Output port (25) can be adapted to communicate with an inlet port (118)
of a second stage pressure regulator (110), as illustrated in Figures 5 and 6.
In
one embodiment, pressure regulator (110) is a balanced pressure regulator.
Pressure regulator (110) includes spring housing (112) mounted to base (114)
to
form regulator housing (116). Housing (116) includes an inlet port (118)
communicatingwith apintle chamber (120). Pintle chamber (120) communicates
with output chamber (122) and includes a valve seat (123) with orifice (124).
Valve pintle (126) is disposed within pintle chamber (120) and includes a
sealing
member (127) with a sealing surface (128) to press against valve seat (123)
and
thereby close orifice (124). Output chamber (122) communicates with output
port (123) formed within housing (116).
Valve pintle (126) is movable to open and close orifice (124) in response
to the combined action of spring (130) and diaphragm (132). Spring (130) is
provided within housing (116) to exert a force which tends to move the valve
pintle (126) towards an open position wherein sealing surface (128) is
unseated
from valve seat (123), thereby opening orifice (124) into communication with
output chamber (122). Gas pressure inpintle chamber (120) and output chamber
(122) acts against moveable pressure boundary member (131) and valve pintle
(126) thereby opposing forces exerted by spring (130) and tending to move
valve
pintle (126) towards a closed position, wherein sealing surface (128) is
pressed .
against valve seat (123), thereby closing orifice (124). Pintle stem (134)
extends
from valve pintle (126), terminating in pintle nut (136). Pintle nut (I36) is
mountedwithincentralboss(138). Centralboss(138)extendsthroughthecentre
of moveable pressure boundary member (131). A locking ring (144) fits over
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central boss (138) and bears down upon moveable pressure boundary member
(131).
Pressure regulator ( 110) is a balanced regulator with features provided to
mitigate pxessure imbalances which are attributable to unsteady state
conditions,
such as source pressure variability in pintle chamber (120). In this respect,
regulator (110) is furtherprovided with a balancing chamber (170) extending
and
sealed from pintle chamber (120). Valve pintle (126) includes balancing stem
(172) extending from sealing member (127) and disposed within balancing
chamber (170). Valve pintle (126) further includes a throughbore (174)
extending between ports (176) and (178) provided in the surface of valve
pintle
(126). Port (I76) opens into communication with output chamber (122). Port
(178) opens into communication with balancing chamber (170). Balancing
chamber (170) is sealed from pintle chamber (120) by sealing member (180),
I S such as an o-ring, which is carried within a groove (182) provided within
internal
surface (184) of balancing chamber (170). By virtue of this arrangement,
balancing chamber (170) is in direct communication with output chamber (122).
To mitigate the effects of pressure variability within pintle chamber (120) on
the
regulation of pressure by the combined action of diaphragm assembly (131) and
valve pintle (126), the cross-sectional area of balancing stem is made
substantially the same as the seating area of sealing surface (128). This
substantially reduces the significance of pressure in pintle chamber (120) on
the
regulatory function of diaphragm assembly (131) and valve pintle (126).
Spring (130) is fitted over locking ring (144), and is supported on
diaphragm support plate (142). Spring (130) is retained within a spring
chamber
(146) formed within housing (116). Spring (130) can include coil springs,
spring
washers, or elastomeric-type springs.
In one embodiment, moveable pressure boundary member (131) is a
diaphragm assembly comprising diaphragm (132), first diaphragm plate (140),
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~. AUGUST 2ap1 ~~ ~ ~ . , .. . ... .....,.
and diaphragm support plate (142). Diaphragm (132) is mounted on a first
diaphragm plate (40) disposed on one side of diaphragm (132) and extending
from central boss (138). The diaphragm (132) is retained on the first
diaphragm
plate (140) by means of a diaphragm support plate ( 142) and a locking ring
(14Q.).
As such, diaphragm (132) is interposed and pinched between first diaphragm
plate (140) and diaphragm support plate (142). Groove (148) is formed within
housing (116) to receive diaphragm (132), thereby securing diaphragm (132) to
.
housing (116). In this respect, diaphragm (132) seals output chamber (122)
from _
spring chamber (146), thereby isolating output chamber (122) from spring,
chamber (146). Diaphragm (132) is generally characterized by a flat profile.
Diaphragm (132) includes a first side surface (156) and second side surface
(158). .
First side surface (156) is exposed to gas within output chamber (122).
Diaphragm (132) further includes a throughbore (160) which receives central
boss (138). In one embodiment, diaphragm (132) includes'a mlling convolution
(150) extending from a section (152) characterized by a flat profile, to
provide a
modification in the behaviour of diaphragm (132). Specifically, this design
attempts to ensure that diaphragm (132) is always in tension i.e. never in
shear _ _ . _ . _
.. . ~ or compression). Thus, as the convolution rolls, diaphragm (132) .is
neve~,:~:.,:.4 ... :.",._;...._...., -....
stretched or buckled i.e. ~ largely eliminating hysteresis) ~ , ~ . . ' . ; .
~ : _ , -' :~ . . . , . . .
Like pressure regulator (10), pressure regulator (110) is characterized by
an orientation wherein transverse axis (161) of moveable pressure boundary
- - member (131) is transverse to longitudinal axis (62) of neck (6). As a
fiuther . _- : - . -
' ' '- ~ incident,' moveable pressure boundary' member (i31) Lies ~'or is
~dispbsed'~'~' .. .: ~ ' ~ ~ - ~ ' -
substantially in a plane which is parallel to the longitudinal axis (62) of
neck (6). ..
Such orientation permits the use of a relatively larger moveable pressure
boundary member (132) within module (2) .where it is desired to miniirtize the
diameter or width of neck (6). Use of larger diameter moveable pressure ..
boundary members (131) in pressure regulators is desirable so that the
pressure
. boundary member is more sensitive to pressure changes in the output chamber
(122), thereby providing a more accurate response to these pressure changes
and
-12-
rte, ~
2°~ - ~°~ ~~~~~. a '~~° ~ ~~~ ~~ ~ '. - ; .. . ~ .. .' .-
~; ~8,-10 2001
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changes and mitigating droop. Because moveable pressure boundary member
(131) is oriented in this fashion, more space is available within module (2)
for the
formation of various flow passages necessary for permitting internal mounting
of
a solenoid shut-off valve in conjunction with a regulator.
In one embodiment an adjustable member, such as a screw (164), is
provided and extends through housing (116) to regulate compression of
associated spring (130), thereby varying flow control characteristics of valve
pintle (126).
A vent passage (84) is also formed within housing (16) to communicate
with spring chamber (46). Any gas leaking across diaphragm (3) from output
chamber (22) and into spring chamber (46) is thereby vented to pxevent
accumulation of gas within spring chamber (46). Where pressure regulation is
accomplished by first and second stage regulators (10) and (100) in series,
spring
chamber (46) of first stage regulator ( 10) vents to output chamber (122) of
second
stage regulator (110), while spring chamber (I46) of second stage regulator
(110)
vents via passage (184) to atmosphere via port (316) formed within head (4).
In one embodiment, gas within vessel (216) is characterized by a pressure
of about 5000 psig. As gas flows across first stage regulator (10), pressure
is
dropped to about 300 to 500 psig. Pressure is further reduced through second
stage regulator (110) such that pressure in output chamber (122) is about 115
psig.
Referring to Figures 5, 13 and 14, gas flowing from a second stage
regulator (I10) through outlet port (125) is connected to outlet passage (300)
which communicates with outlet port (310) formed within head (4). Optionally
connected to outlet passage (300) is a pressure relief device (312) installed
in port
(314) in head (4). ~'ressure relieve device (312) vents to a relief outlet
connection
(313).
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Sensor ports (318) and (320) can also be formed within head (4) fox
receiving installation of high pressure and low pressure sensors (322) and
(324)
respectively. High pressure sensor (322) senses pressure within fluid passage
(64), which connects inlet port (18) of regulator (10) with outlet port (218)
of
solenoid shut off valve (210) (see Figures 13 and 14). High pressure sensor
(322), therefore, measures gas pressure entering regulator (10). In this
respect,
throughbore (326) connects sensor (318) to throughbore (329). On the other
hand, low pressure sensor (324) senses pressure within outlet passage (300)
and,
therefore, measures gas pressure leaving the regulator assembly (10) and
(110).
In this respect, throughbore (328) connects sensor port (320) to outlet
passage
(300).
As illustrated in Figure 5, inlet port (18) communicates with high
pressure gas stored in pressure vessel (216) through solenoid shut off valve
(210).
Solenoid shut off valve (210) controls gaseous flow out of pressure vessel
(216).
Solenoid shut off valve (210) includes an inlet port (220) and an outlet port
(218).
Outlet port (218) communicates with inlet port (18) of regulator (10) via a
fluid
passage (64). A manual shut-off valve (330) (see Figures 5 and 7) is provided
to interrupt flow between solenoid shut off valve (210) and inlet port (18).
In one embodiment, solenoid shut-off valve (210) is an instant-on type
valve. Refernng to Figure 8, instant-on valve (210) includes a valve body
(212)
configured for mounting within a nozzle (217) of a pressure vessel (216). The
pressure vessel (216) includes a storage volume (216). Valve body (212)
includes
an outlet port (218) and an inlet port (220). A flow passage (224) extends
from
the outlet port (218) and through the valve body (212) and is in communication
with inlet port (220). A valve seat (226) is provided in flow passage (224).
Valve seat (226) defines an orifice (228). Bore (229) extends between outlet
port
(218) and orifice (228) and forms part of flow passage (224).
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Valve body (210) includes a conduit (211). Conduit (211) includes a first
conduit orifice (254), a second conduit orifice (221), and a third conduit
orifice
(228). Second conduit orifice (221) functions as inlet port (220).
Conduit (2I1) includes a sleeve (222). Primary piston (232) and
secondary piston (231) are disposed and slidably carried within sleeve (222)
of
conduit (211), and are moveable therein. Secondary piston (231) is interposed
between primary piston (232) and first conduit orifice (254). Sleeve (222)
includes a first end (248) and a second end (250). First end (248) is open for
communication with flow passage (224). Second end (250) includes a valve seat
(252) with orifice (254) foamed therein. Sidewalk (251) extend from valve seat
(252) and terminate at a distal end (253) whereby second end (250) is defined.
Sleeve (222) communicates with pressure vessel (216) via orifice (254).
Primary piston (232) includes a body (233) comprising a first end (234)
and a second end (236). Primary piston (232) is comprised of non-magnetic
material. A bore, functioning as a bleed passage (244), is disposed within
body
(233) and extends therethrough between a first aperture (246) at first end
(234)
and a second aperture (242) at second end (236). Second aperture (242) defines
orifice (243). Aperture (246) opens into flow passage (224), and particularly
bore (229). Aperture (242), as well as orifice (243), communicates with flow
passage (224) via bleed passage (244). A sealing member (256), such as an o-
ring, is carried at the periphery of body (233) between body (233) and sleeve
(222) of conduit (211), thereby creating a seal to prevent gas from flowing
between orifice (254) and frst end (248) of sleeve (222). In this respect,
secondary piston (232) is sealingly engaged to conduit (211).
The first end (234) of primary piston (232) includes a valve comprising
a sealing surface (238) for closing the orifice (228). The first end (234) is
further
characterized by a surface (235) exposed to gaseous pressure within pressure
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vessel (216). The second end (236) includes a valve seat (240). Orifice (243)
is
disposed in valve seat (240).
As is illustrated in Figure 1, each of orifice (243) and orifice (254) is
characterized by a cross-sectional area smaller than that of orifice (228).
This
facilitates faster unseating of primary piston (231) from valve seat (226) and
unsealing of third conduit orifice (228), as will be described below.
In one embodiment, orifice (243) is characterized by a smaller cross-
sectional area than orifice (254). This facilitates bleeding of gas from
sleeve
(222) through bleed passage (244), as will be hereinafter described.
Secondarypiston (231) is disposedbetweenprimarypiston (232) and first
conduit orifice (254). Secondary piston (231) includes a first end (258) and a
second end (260). Secondary piston (231) is comprised of magnetic material.
First end (258) includes a valve comprising a sealing surface (262) for
closing
orifice (243). Second end (262) includes a valve comprising a second sealing
surface (264) for engaging valve seat (252), thereby closing orifice (254).
Resilient member or spring (266) bears against secondary piston (231) to bias
secondary piston (231) towards primary piston (232) for pressing first sealing
surface (262) against valve seat (240) and thereby close orifice (243). In one
embodiment, spring (266) is housed at second end (250) of sleeve (222) and
presses against second end (260) of secondary piston (231).
Surrounding sleeve (222) is a solenoid coil (268). Solenoid coil (268) is
provided to apply electromagnetic forces on secondary piston (231) by external
actuation, thereby causing movement of the secondary piston (231) against the
force of spring (266) and fluid pressure forces within sleeve (222).
Figures 8,9, and 10 illustrate an embodiment of an instant-on valve (210)
of the present invention in various conditions of operation. Figure 8
illustrates
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instant-on valve (210) in a closed position. In this condition, solenoid coil
(268)
is not energized. Under these circumstances, spring (266) biases
secondarypiston
(231 ) towards primary piston (232). In this respect, second sealing surface
(264)
is spaced from orifice (254) of valve seat (252) in sleeve (222), thereby
opening
orifice (254) to fluid pressure in the pressure vessel (216).
Contemporaneously,
first sealing surface (262) on secondary piston (231 ) is pressed against
valve seat
(240) on primary piston (232), thereby closing orifice (243). Because orifice
(254) in sleeve (222) is open to fluid pressure in pressure vessel (216), the
spaces
between sealing member (256) and orifice (254) are also exposed to fluid
pressure ofpressure vessel (216). Turning to primarypiston (232), first end
(234)
of primary piston (232) is exposed to fluid pressure within pressure vessel
(216)
via inlet port (220). These fluid forces, acting upon primary piston (232) are
overcome by the combined action of spring (266) and fluid pressure within
sleeve
(222), the latter forces being translated to primary piston (232) by secondary
piston (231). As such, sealing surface (238) on primary piston (232) is
pressed
against valve seat (226), thereby closing orifice (228).
Figure 9 illustrates instant-on valve (210) in a transition position. Tnstant-
on valve (210) is in a transition position moments after solenoid coil (268)
is
energized. Moments after solenoid coil (268) is energized, electromagnetic
forces produced thereby act upon secondarypiston (231) and overcome the forces
exerted by spring (266) and gas pressure within sleeve (222), thereby causing
second sealing surface (264) in secondary piston (231) to seat against valve
seat
(252) provided on sleeve (222), thereby closing orifice (254). Simultaneously,
first sealing surface (262) on secondarypiston (231 ) retracts from valve seat
(240)
of primary piston (32), thereby opening orifice (43). By opening orifice (243)
in
primarypiston (232), gas contained within sleeve (222) begins to escape
through
bleed passage (244) within primarypiston (232) via orifice (243) and flow out
of
instant-on valve (210) through outlet port (218). As this happens, gas
pressure
within sleeve (222) begins to drop. However, under these conditions, fluid
pressure in this region has not dropped sufficiently to unseat primary piston
(232)
from valve seat (226). This is because the fluid forces acting on the surface
of
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first end (234) of primary piston (232), including fluid forces within bore
(229),
are still insufficient to overcome fluid forces within sleeve (222) acting
upon the
surface of second end (236) of primary piston (232).
Figure 10 illustrates instant-on valve (210) in an open position. In this
condition, fluid within sleeve (222) between sealing member (256) and orifice
(254) has further escaped through bleed passage (244) in primary piston (232).
At this point, gaseous forces acting behind the surface of second end (236)
have
sufficiently subsided to have become overcome by the fluid forces acting upon
the surface of first end (234) ofprimarypiston (232). Inresponse, sealing
surface
(238) ofprimarypiston (232) has become unseated from valve seat (226), thereby
creating an uninterrupted flow path between the interior of pressure vessel
(216)
and outlet port (218) via fluid passage (224).
Referring to Figures 5, 7,11 and 13 pressure vessel (216) is filled with
a gaseous mixture using module (2) through flow passages extending through
instant-on valve (210). Gas enters module (2) via inlet port (331), passing
through filter (334) (flow direction denoted by arrows (333) in Figure 13),
and
travelling through passage (329) for communication with the interior of
pressure
vessel (216) via orifice (228). Gas flowing through orifice (228) presses upon
secondary piston (232), causing unseating of secondary piston (232) from valve
seat (226) of flow passage (224). As a result, an uninterrupted flowpath is
created
between inlet port (331) and the interior of pressure vessel (216). When the
filling operation is complete, spring (266) exerts sufficient force on primary
piston (231), which is thereby transmitted to secondary piston (232), to cause
secondary piston (232)-to close orifice (228).
Figures 5, 7 and I2 illustrates the disposition of manual shut-off valve
(330) within passage (329) between outlet port (218) and orifice (228),
thereby
permitting manual shut-off of fluidpassage (224). In this respect, apassage
(329)
is provided within neck (6), extending from port (342) provided in head (4).
Passage (329) includes a second valve seat (334) with an orifice (336)
interposed
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between inlet port (18) of regulator (10) and orifice (228). Manual shut-off
valve
(330) includes a sealing surface (338) for seating against valve seat (334),
thereby
closing orifice (336) and blocking flow passage (224) such that communication
between regulator ( 10) and instant-on valve (210) is interrupted. As such,
manual
shut-off valve (330) is co-axial with the fluid passage used to fill pressure
vessel
(216). Stem (340) extends from sealing suxface (338) and through port (342)
via
passage (329). Manual actuator (344) is provided at distal end (346) of stem
(340) to facilitate closing of flow passage (224) by manual intervention.
Other ports are provided in head (4) to facilitate operation of the above-
described components of module (2) (see Figure 13). Thermally actuated relief
device (348) can be provided within throughbore (352) to vent tank gases in
the
case of a fire to prevent explosions. Throughbore (352) vents to outlet
connection
(313) (see Figures 13 and 14). Port (354) is also provided with passage (356)
extending therefrom, thereby functioning as a wire pass through and permitting
electrical connection of instant-on valve (210) exterior to the pressure
vessel
(216).
As illustrated in Figures 1, 5 and 7, module (2) is adapted for mounting
within nozzle (217) of pressure vessel (216). Nozzle (217) includes an
aperture
(227), and is characterized by a longitudinal axis (221). Head (4) extends
outside
nozzle (217) and, therefore, functions as a cap. Neck (6) depends from head
(4)
and extends into the interior (219) of pressure vessel (216). In this respect,
when
module (2) is mounted within nozzle (217) in this manner, each of the
regulators
(10) and (110) and solenoid shut-off valve (210) are disposed within the
interior
of (219) of pressure vessel (216). Also, each of moveable pressure boundary
members (31) and (131) are oriented such that each of their respective
transverse
axes (61) and (161) is transverse to longitudinal axis (62) of neck (6) or
longitudinal axis (221) of nozzle (217). In one embodiment, the transverse
axis
(61) or (161) is perpendicular to the longitudinal axis (62) of neck (61). As
a
further incident, each of moveable pressure boundary memb ers (31 ) and ( 131
) lies
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or is disposed substantially in a plane which is parallel to the longitudinal
axis
(62) of neck (6) or the longitudinal axis (221) of nozzle (217).
Although the disclosure describes and illustrates preferred embodiments
of the invention, it is to be understood that the invention is not limited to
these
particular embodiments. Many variations and modifications will now occur to
those skilled in the art. For definition of the invention, reference is to be
made
to the appended claims.
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