FAULT-TOLERANT BLEED VALVE ASSEMBLY
Background
The versatility and flexibility of hydraulic systems give it many
advantages over other methods of transmitting power. However, like many power
systems, proper care of the hydraulic system must be taken in order to prevent
problems.
A typical problem that can occur in hydraulic systems is aeration.
Aeration in hydraulic systems is commonly caused by air entering the hydraulic system
through a leak in an inlet line or as a result of a low fluid level in the reservoir. If the
air in the fluid of the hydraulic system is not released, the air will implode against
components of the pump. This implosion of air releases large amounts of energy that
can result in damage to the pump, which over time can result in premature failure of the
pump.
While prior art air-vent valves have been used to release air in the
hydraulic system, such valves do not protect against hydraulic leakage from the valve as
a result of a valve component failure. Leakage in hydraulic systems can be problematic
since it drains the hydraulic system of hydraulic fluid. As the hydraulic fluid of the
hydraulic system decreases, the fluid level in the reservoir decreases. As previously
stated, the risk of aeration in the hydraulic system increases as the amount of hydraulic
fluid in the hydraulic system decreases, which potentially decreases the life of the
components of the hydraulic system.
Summary
An aspect of the present disclosure relates to a bleed valve assembly.
The bleed valve assembly includes a control assembly having a fluid inlet, a fluid outlet
and a fluid passageway in fluid communication with the fluid inlet and the fluid outlet.
An electromechanical valve is disposed is the control assembly. The electromechanical
valve provides selective fluid communication between the passageway and the fluid
outlet. A fluid sensor is in fluid communication with the passageway. The fluid sensor
includes a sensing tip and is in electrical communication with the electromechanical
valve. A valve assembly is disposed in the passageway of the control assembly. The
valve prevents fluid communication of non-gaseous fluid between the fluid inlet and the
fluid outlet.
Another aspect of the present disclosure relates to a bleed valve
assembly for a hydraulic system. The bleed valve assembly includes a control assembly
that has a fluid inlet and a fluid outlet. The control assembly includes a first housing
and a second housing. The first and second housings cooperatively define a
passageway that is in fluid communication with the fluid inlet and the fluid outlet. The
first housing defines a first portion of the passageway while the second housing defines
a second portion of the passageway. A fluid sensor is disposed in the first housing. The
fluid sensor includes a sensing tip that is at least partially disposed in the first portion of
the passageway. A solenoid valve is disposed in the second housing. The solenoid
valve includes an armature that is selectively disposed in the second portion of the
passageway. The armature provides selective fluid communication between the
passageway and the fluid outlet. A valve assembly is disposed between the first
housing and the second housing. The valve assembly includes a float member and a
valve seat having a fluid passage through the valve seat. The float member is adapted
to prevent non-gaseous fluid from contacting the solenoid valve by blocking the flow of
non-gaseous fluid through the fluid passage of the valve seat.
Another aspect of the present disclosure relates to a hydraulic system.
The hydraulic system includes a fluid reservoir. The hydraulic system further includes
a passageway. The passageway is in fluid communication with the upper portion of the
fluid reservoir. A fluid sensor includes a sensing tip that is in fluid communication with
the passageway. The fluid sensor is disposed downstream of the fluid reservoir. An
electromechanical valve is disposed downstream of the fluid sensor. The
electromechanical valve includes an armature that is selectively disposed in the
passageway. The armature is adapted to selectively vent gaseous fluid in the
passageway in response to an electrical signal from the fluid sensor. A back-up valve
assembly is disposed in the passageway between the fluid sensor and the
electromechanical valve. The back-up valve assembly includes a valve seat and a float
member. The valve seat and the float member are adapted to prevent non-gaseous fluid
from flowing downstream of the back-up valve assembly,
A variety of additional aspects will be set form in the description that
follows. These aspects can relate to individual features and to combinations of features.
It is to be understood that both the foregoing general description and the following
detailed description are exemplary and explanatory only and are not restrictive of the
broad concepts upon which the embodiments disclosed herein are based.
Description of the Drawings
FIG. 1 is a schematic of a hydraulic system having features that are
examples of aspects in accordance with the principles of the present disclosure.
FIG. 2 is a perspective view of a bleed valve assembly suitable for use in
the hydraulic system of FIG. 1.
FIG. 3 is a front view of the bleed valve assembly of FIG. 2.
FIG. 4 is a left side view of the bleed valve assembly of FIG. 2.
FIG, 5 is a cross-sectional view of the bleed valve assembly taken on line
5-5 of FIG. 4.
FIG. 6 is a schematic representation of a first light path in an electro-
optic sensor suitable for use in the hydraulic system of FIG. 1.
FIG. 7 is a schematic representation of a second light path in the electro-
optic sensor.
FIG. 8 is a perspective view of a float seat suitable for use in the
hydraulic system of FIG. 1.
FIG. 9 is a front view of the float seat of FIG. 8.
FIG. 10 is a cross-sectional view of the float seat taken on line 10-10 of
FIG. 9.
Detailed Description
Reference will now be made in detail to the exemplary aspects of the
present disclosure that are illustrated in the accompanying drawings. Wherever
possible, the same reference numbers will be used throughout the drawings to refer to
the same or like structure.
Referring now to FIG. 1, a schematic representation of a simplified
hydraulic system, generally designated 10, is shown. The hydraulic system 10 includes
a reservoir 12, a pump 14, an actuator 16, which is shown herein as a motor, and a bleed
valve assembly, generally designated 20. In one embodiment, the hydraulic system 10
is disposed on an aerospace application such as an aircraft
In the subject embodiment, the reservoir 12 provides a receptacle for
holding fluid for the hydraulic system 10. A fluid inlet of the pump 14 and a fluid
outlet of the actuator 16 are in fluid communication with the reservoir 12.
As previously stated, a typical problem in hydraulic systems is the
presence of air in the hydraulic fluid of the hydraulic system. If this air in the hydraulic
fluid of the hydraulic system 10 is not released, the air may implode against
components of the pump 14, thereby resulting in potentially damage to the pump 14.
In the subject embodiment, the bleed valve assembly 20 is adapted to
detect and relieve air in the hydraulic system 10. In the depicted embodiment of FIG. 1,
the bleed valve assembly 20 is in fluid communication with a top portion of the
reservoir 12.
Referring now to FIGS. 1 and 2, an embodiment of the bleed valve
assembly 20 is shown. The bleed valve assembly 20 includes a control assembly,
generally designated 22. The control assembly 22 includes a fluid sensor 24, a valve
assembly, generally designated 26, and an electromechanical valve 28, each of which
will be described in greater detail subsequently.
Referring now to FIGS. 2-5, the control assembly 22 includes a first
housing 30 and a second housing 32. In the subject embodiment, the first and second
housings 30, 32 arc held together in tight sealing engagement by a plurality of fasteners
34 (e.g., bolts, screws, etc.). It will be understood, however, that the scope of the
present disclosure is not limited to the first and second housings 30, 32 being in tight
sealing engagement as the first and second housings 30, 32 could be separately disposed
in the control assembly 22.
Each of the first and second housings 30, 32 defines a fluid port 36 for
receiving or discharging fluid. In the subject embodiment, the first housing 30 defines a
fluid inlet port 36a for receiving fluid while the second housing 32 defines a fluid outlet
port 36b for discharging fluid. The first and second housings 30, 32 of the control
assembly 22 further define a fluid passageway 38 that provides fluid communication
between the fluid inlet and outlet ports 36a, 36b.
In the subject embodiment, the first housing 30 defines a first portion 40
of the fluid passageway 38. The first portion 40 of the fluid passageway 38 extends
from the fluid inlet port 36a to a first cavity 42 in an end surface 44 of the first housing
30. In the subject embodiment, the first cavity 42 has a larger diameter than the first
portion 40 of the fluid passageway 38.
The first housing 30 includes a sensor port 46. The sensor port 46 is in
fluid communication with the first portion 40 of the fluid passageway 38 between the
fluid inlet port 36a and the first cavity 42. The sensor port 46 is adapted to receive the
fluid sensor 24. In one embodiment, the sensor port 46 includes a plurality of internal
threads that are adapted to receive a plurality of external threads on the fluid sensor 24.
The first housing 30 further includes a mount 48. The mount 48 is
adapted for mounting the bleed valve assembly 20 to the reservoir 12. In the subject
embodiment, the mount 48 extends outwardly from a side 50 of the first housing 30.
The mount 48 defines a plurality of holes 52 that extends through the mount 48 and is
adapted for receiving a plurality of mounting fasteners 54. In the subject embodiment,
and by way of example only, the mount 48 includes four holes 52.
The mount 48 of the first housing 30 further includes a connector 56 that
is engaged with the fluid inlet port 36a. In the subject embodiment, the engagement
between the connector 56 and the fluid inlet port 36a is a threaded engagement. The
connector 56 defines a passage 58 (shown with dashed lines in FIG. 4) through the
center of the connector 56 that is in fluid communication with the fluid inlet port 36 a.
The connector 56 includes an exterior surface 60 that is adapted for receipt in a port on
the reservoir 12.
The second housing 32 defines a second portion 62 of the fluid
passageway 38. The second portion 62 of the fluid passageway 38 extends from the
fluid outlet port 36b to a second cavity 64 in an end surface 66 of the second housing
32. In the subject embodiment, the second cavity 64 has an inner diameter that is about
equal to the inner diameter of the first cavity 42 in the first housing 30 and that is
generally larger than the inner diameter of the second portion 62 of the fluid
passageway 38.
The second housing 32 includes a valve port 68. The valve port 68 is in
fluid communication with the second portion 62 of the fluid passageway 38 between the
fluid outlet port 36b and the second cavity 64. The valve port 68 is adapted to receive
the electromechanical valve 28.
Referring now to FIGS. 5-7, the fluid sensor 24 will be described. The
fluid sensor 24 is an electro-optic sensor. Fluid sensors 24 suitable for use with the
bleed valve assembly 20 are sold commercially by Eaton-Tedeco as Intellisense
LevelPro Series Liquid Level Sensors.
The fluid sensor 24 includes a body 70 having a sensing tip 72. The
sensing tip 72 is made of a transparent material (e.g., glass, plastic, etc.) and is shaped
generally as a prism. In the subject embodiment, the sensing tip 72 of the fluid sensor
24 is at least partially disposed in the first portion 40 of the fluid passageway 38.
A light source (e.g., light emitting diode, etc.) 74, a light receiver 76 and
a microprocessor 78 are disposed in an inner cavity of the body 70 of the fluid sensor
24. The light source 74 transmits light to the sensing tip 72. If the sensing tip 72 is
disposed in non-gaseous fluid, the light emitted from the light source 74 follows a first
light path in which the light is reflected back to the light receiver 76 in the inner cavity
of the fluid sensor 24 as shown in FIG. 6. If the sensing tip 72 is disposed in gaseous
fluid, such as air, the light emitted from the light source 74 follows a second light path
in which the light refracts through the sensing tip 72 as shown in FIG. 7.
Referring now to FIG. 5, the electromechanical valve 28 will be
described. In the subject embodiment, the electromechanical valve 28 is a solenoid
valve having a coil 80 and an armature 82.
At least a portion of the armature 82 is disposed in a bore of the coil 80.
The armature 82 includes an end portion 84 that extends outwardly from the bore of the
coil 80 and is disposed in second portion 62 of the fluid passageway 38. The end
portion 84 of the armature 82 selectively blocks fluid communication between the fluid
inlet port 36a and the fluid outlet port 36b of the bleed valve assembly 20. In the
subject embodiment, the armature 82 is biased to a closed position in which the fluid
communication between the fluid inlet port 36a and the fluid outlet port 36b is blocked.
In one embodiment, a spring 86 biases the armature 82 to the closed position.
Referring now to FIGS. 5-7, the operation of the fluid sensor 24 and the
electromechanical valve 28 will be described. In the subject embodiment, the coil 80 is
in selective electrical communication with the microprocessor 78 of the fluid sensor 24.
In response to a signal received from the light receiver 76 of the fluid sensor 24, the
microprocessor 78 actuates the coil 80 of the electromechanical valve 28 accordingly.
For example, if the sensor tip 72 is disposed in gaseous fluid (e.g., air, etc.), the light
receiver 76 does not receive light emitted from the light source 74 since the emitted
light is refracted out the sensor tip 72. In this situation, the microprocessor 78 of the
fluid sensor 24 receives a signal from the light receiver 76 and actuates the coil 80 of
the electromechanical valve 28. When the coil 80 is actuated, the armature 82 retracts
into the bore of the coil 80 to an open position. With the armature 82 in the open
position, the fluid outlet port 36b is in open fluid communication with the fluid inlet
port 36a, thereby allowing fluid in the fluid passageway 38 to flow out the fluid outlet
port 36b.
If, however, the sensing tip 72 of the fluid sensor 24 is disposed in non-
gaseous fluid (e.g., hydraulic fluid, etc.), the light receiver 76 of the fluid sensor 24
receives light emitted from the light source 74 which is reflected off the sensing tip 72
as shown in FIG. 6. In this situation, the microprocessor 78 of the fluid sensor 24 does
not actuate the coil 80 of the electromechanical valve 28. As the electromechanical
valve 28 is biased to the closed position in which fluid communication between the
fluid inlet port 36a and the fluid outlet port 36b is blocked, the non-gaseous fluid is
prevented from being discharged from the fluid outlet port 36b.
In the subject embodiment, the microprocessor 78 of the fluid sensor 24
is adapted to interpret signals received from the light receiver 76. For example, the
microprocessor 78 can be programmed to identify droplets of fluid on the sensing tip
72, ambient light, and splashing of non-gaseous fluid on the sensing tip 72. This
identification reduces or eliminates false operation of the fluid sensor 24 and false
operation of the bleed valve assembly 20.
Referring now to FIGS. 5 and 8-10, the valve assembly 26 is shown. In
the subject embodiment, the valve assembly 26 provides a back-up or fault tolerant
feature to the bleed valve assembly 20. For example, if the armature 82 of the
electromechanical valve 28 fails to fully extend from the coil 80 and, therefore, fails to
fully block the fluid passageway 38 or if the fluid sensor 24 falsely actuates the coil 80
of the electromechanical valve 28, the valve assembly 26 is adapted to prevent non-
gaseous fluid from the reservoir 12 from being discharged through the fluid outlet port
36b. This feature is advantageous as it allows the reservoir 12 to retain its volume of
fluid in the event of a fluid sensor 24 or electromechanical valve 28 failure. The valve
assembly 26 includes a float member 90 and a float seat 92.
In the subject embodiment, the float member 90 is generally spherical in
shape and hollow bodied. In the depicted embodiment of FIG. 5, the float member 90 is
disposed in the first cavity 42 of the first portion 40 of the fluid passageway 38. In
order to retain the float member 90 in the first cavity 42, the outer diameter of the float
member 90 is larger than the inner diameter of the first portion 40 of the fluid
passageway 38.
Referring now to FIGS. 8-10, the float seat 92 is shown. The float seat
92 includes a valve scat 94 and a flange 96.
The valve seat 94 is generally cylindrical in shape and includes a first
axial end portion 98a and an oppositely disposed second axial end portion 98b. The
valve seat 94 defines a fluid passage 100 that extends through the first and second axial
end portions 98a, 98b along a longitudinal axis 102 of the valve seat 94. An inner
diameter of the fluid passage 100 is smaller than the outer diameter of the float member
90.
The first axial end portion 98a of the valve seat 94 defines a first opening
104 to the fluid passage 100. In the subject embodiment, an inner diameter of the first
opening 104 tapers from a first axial end surface 106 of the first axial end portion 98a to
the fluid passage 100. The inner diameter of the first opening 104 at the first axial end
surface 106 is larger than the outer diameter of the float member 90 such that the float
member 90 can be received within the first opening 104.
A first exterior surface 108 of the first axial end portion 98a is sized for
receipt in the first cavity 42 of the first housing 30. The first exterior surface 108 of the
first axial end portion 98a defines a first groove 110. In the subject embodiment, the
first groove 110 is adapted to receive a first sealing member 112, such as an o-ring
(shown in FIG. 5), which is adapted to provide a fluid seal between the first axial end
portion 98a and the first cavity 42 of the first housing 30.
The second axial end portion 98b of the valve seat 94 defines a second
opening 114 to the fluid passage 100. In the subject embodiment, an inner diameter of
the second opening 114 tapers from a second axial end surface 116 of the second axial.
end portion 98b to the fluid passage 100.
A second exterior surface 118 of the second axial end portion 98b is
sized for loose fitting engagement with the second cavity 64 of the second housing 32.
The second exterior surface 118 of the second axial end portion 98b defines a second
groove 120. In the subject embodiment, the second groove 120 is adapted to receive a
second sealing member 122, which is adapted to provide a fluid seal between the
second axial end portion 98b and the second cavity 64 of the second housing 32.
The flange 96 of the float seat 92 extends outwardly from the valve seat
94 in a direction that is generally perpendicular to the longitudinal axis 102. In the
subject embodiment, the flange 96 is disposed longitudinally along the valve seat 94
such that the first axial end portion 98a and the second axial end portion 98b are
generally symmetrical. This symmetrical arrangement of the first and second axial end
portions 98a, 98b provides for ease of assembly of the bleed valve assembly 20 as the
first and second axial end portions 98a, 98b will fit in both the first and second cavities
42, 64 of the first and second housings 30, 32.
In the subject embodiment, the flange 96 is adapted for disposition
between the end surface 44 of the first housing 30 and the end surface 66 of the second
housing 32. The flange 96 defines a plurality of thru-holes 124 that is adapted to
receive the plurality of fasteners 34. In the subject embodiment, the outer perimeter of
the flange 96 is shaped similarly to the outer perimeter of the first and second housings
30, 32.
Referring now to FIGS. 1 and 5, the operation of the fault tolerant
feature of the bleed valve assembly 20 will now be described. Fluid from the reservoir
12 enters the bleed valve assembly 20 through the fluid inlet port 36a. The fluid enters
the first portion 40 of the fluid passageway 38 and comes into contact with the sensing
tip 72 of the fluid sensor 24. If the fluid is gaseous, light from the light source 74 of the
fluid sensor 24 is refracted through the sensing tip 72. When the light is refracted
through the sensing tip 72, the light receiver 76 sends a signal to the microprocessor 78.
In response to the signal from the light receiver 76, the microprocessor actuates the coil
80 of the electromechanical valve 28.
The gaseous fluid in the first portion 40 of the fluid passageway 38 flows
around the float member 90 and into the fluid passage 100 of the valve assembly 26. As
the float member 90 is a hollowed body member, the pressure of the gaseous fluid is
able to raise the float member 90 such that the gaseous fluid can flow around the float
member 90 and into the fluid passage 100.
The gaseous fluid then flows into the second portion 62 of the fluid
passageway 38. With the coil 80 of the electromechanical valve 28 actuated, the
gaseous fluid flows through the second portion 62 and out the fluid outlet port 36b.
If the electromechanical valve 28 remains in the open position rather
than returning to the closed position when non-gaseous fluid is disposed in the first
portion 40 of the fluid passageway 38, the valve assembly 26 prevents the non-gaseous
fluid from entering the second portion 62 of the fluid passageway 38. As the non-
gaseous fluid passes into the first cavity 42 of the first housing 30, the float member 90
raises and enters the first opening 104 of the first axial end portion 98a of the valve seat
94. The float member 90 rises until it blocks the non-gaseous fluid from entering the
fluid passage 100 of the valve seat 94. With the float member 90 blocking the fluid
from entering the fluid passage 100 of the valve seat 94, the non-gaseous fluid is
prevented from flowing through the fluid outlet port 36b even though the
electromechanical valve 28 is in the open position.
The valve assembly 26 of the bleed valve assembly 20 is potentially
advantageous as it prevents the reservoir 12 from emptying as a result of erroneous
actuation of the electromechanical valve 28 or the electromechanical valve 28 being
held in the open position. While in a preferred embodiment the valve assembly 26 is
positioned between the fluid sensor 24 and the electromechanical valve 28, the scope of
the present disclosure is not limited to me valve assembly 26 being between the fluid
sensor 24 and the electromechanical valve 28. In an alternate embodiment, the valve
assembly 26 could be positioned between the electromechanical valve 28 and the fluid
outlet port 36b. However, with the valve assembly 26 disposed between the fluid
sensor 24 and the electromechanical valve 28, the valve assembly 26 keeps the
electromechanical valve 28 free from contact with non-gaseous fluid which could
potentially improve the life of the electromechanical valve 28.
While the bleed valve assembly 20 has been described with regard to air
in the hydraulic system 10, it will be understood that the scope of the present disclosure
is not limited to using the bleed valve assembly 20 in a hydraulic system as the bleed
valve assembly 20 could be adapted for relieving any gaseous fluid from a non-gaseous
fluid system.
Various modifications and alterations of this disclosure will become
apparent to those skilled in the art without departing from the scope and spirit of this
disclosure, and it should be understood that the scope of this disclosure is not to be
unduly limited to the illustrative embodiments set forth herein.
WE CLAIM
1. A bleed valve assembly (20) comprising:
a control assembly (22) having a fluid inlet (36a), a fluid outlet (36b) and a
passageway (38) in fluid communication with tbe fluid inlet and the fluid outlet;
an electromechanical valve (28) disposed in the control assembly, wherein the
electromechanical valve provides selective fluid communication between the
passageway and the fluid outlet;
a fluid sensor (24) having a sensing tip (72) in fluid communication with the
passageway, the fluid sensor being in electrical communication with the
electromechanical valve; and
a valve assembly (26) disposed in the passageway of the control assembly,
wherein the valve assembly prevents fluid communication of non-gaseous fluid between
the fluid inlet and the fluid outlet.
2. A bleed valve assembly as claimed in claim 1, wherein the control assembly
includes a first housing (30) and a second housing (32).
3. A bleed valve assembly as claimed in claim 2, wherein the first housing defines
a first portion (40) of the passageway and the second housing defines a second portion
(62) of the passageway.
4. A bleed valve assembly as claimed in claim 3, wherein the first housing defines
a first cavity (42) in fluid communication with the first portion of the passageway.
5. A bleed valve assembly as claimed in claim 4, wherein the first cavity has an
inner diameter that is greater than an inner diameter of the first portion of the
passageway.
6. A bleed valve assembly as claimed in claim 4, wherein the second housing
defines a second cavity (64) in fluid communication with the second portion of the
passageway.
7. A bleed valve assembly as claimed in claim 6, wherein the second cavity has an
inner diameter that is greater than an inner diameter of the second portion of the
passageway.
8. A bleed valve assembly as claimed in claim 1, wherein the valve assembly
includes a float member (90) and a float seat (92).
9. A bleed valve assembly as claimed in claim 8, wherein the float seat includes a
valve seat (94) and a flange (96) that extends outwardly from the valve seat, the flange
being disposed between the first housing and the second housing.
10. A bleed valve assembly as claimed in claim 1, wherein the sensing tip of the
fluid sensor is an optical prism.
11. A bleed valve assembly as claimed in claim 1, wherein the sensing tip is at least
partially disposed in the passageway.
12. A hydraulic system (10) comprising:
a fluid reservoir (12);
a passageway (38) in fluid communication with an upper portion of the fluid
reservoir;
a fluid sensor (24) having a sensing tip (72) in fluid communication with the
passageway, the fluid sensor being disposed downstream of the fluid reservoir;
an electromechanical valve (28) disposed downstream of the fluid sensor, the
electromechanical valve having an armature (82) selectively disposed in the
passageway, the armature being adapted to selectively vent gaseous fluid in the
passageway in response to an electrical signal from the fluid sensor; and
a back-up valve assembly (26) disposed in the passageway between the fluid
sensor and the electromechanical valve, the back-up valve assembly including a valve
seat (94) and a float member (90), wherein the valve seat and float member are adapted
to prevent non-gaseous fluid from flowing downstream of the back-up valve assembly.
13. A hydraulic system as claimed in claim 12, wherein the fluid sensor is an
electro-optic sensor including a body (70) defining an inner cavity, the electro-optic
sensor having a light source (74), a light receiver (76) and a microprocessor (78)
disposed in the inner cavity.
14. A hydraulic system as claimed in claim 12, further comprising a first housing
(30) in engagement with the fluid sensor and a second housing (32) in engagement with
the electromechanical valve,
15. A hydraulic system as claimed in claim 14, wherein the back-up valve assembly
includes a flange (96) that extends outwardly from the valve seat, the flange being
disposed between the first housing and the second housing.

A bleed valve assembly (20) includes a control assembly (22) having a fluid
inlet (36a) and a fluid outlet (36b). The control assembly defines a fluid
passageway (38) in fluid communication with the fluid inlet and the fluid
outlet. An electromechanical valve (28) is engaged with the control
assembly. The electromechanical valve provides selective fluid
communication between the passageway and the fluid outlet. A fluid sensor
(24) is in fluid communication with the passageway. The fluid sensor
includes a sensing tip and is in electrical communication with the
electromechanical valve. A valve (26) is disposed in the passageway of the
control assembly. The valve prevents fluid communication of non-gaseous
fluid between the fluid inlet and the fluid outlet.