Note: Descriptions are shown in the official language in which they were submitted.
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FLUID FLOW VALVE
FIELD OF THE INVENTION
This invention relates to fluid flow valves of the type adapted on the one
hand to
allow discharge of trapped gas at relatively small or large quantities, and on
the other
hand allow inFress of air so as to provide vacuum relief when the line is
drained.
BACKGROUND OF THE INVENTION
Such air purge valves are generally fitted to liquid conduits such as, for
example,
water mains distribution lines or other liquid supply lines, and are designed
to ensure
the release of air or other gases from the conduits, thereby avoiding the
production of
air locks, for example, which would interfere with the flow of the liquid.
For this purpose, two different kinds of air purge valves are known. In both
kinds, a float is located in a housing which is coupled at a lower end thereof
to. the
conduit to be vented and which is provided at its upper end with a venting
aperture. In
the course of normal operation with the flow of liquid through the conduit,
the housing
fills with liquid and the spherical float is forced upwardly against the
outlet aperture
sealing the same. When, however, air accumulates in the conduit, the float is
displaced
downwardly under its own weight thereby opening the outlet aperture with
consequent
venting of the air.
In a first kind of air purge valve, often referred to as the 'automatic valve,
the
outlet aperture is of relatively small dimensions and the float is displaced
downwardly
as soon as any air appears in the housing, thereby allowing for the
continuous,
automatic venting of the conduit. However, in view of the relatively small
dimensions
of the aperture, this automatic type cannot cope with situations wherein large
quantities
of air have to be vented and where such a situation arises, not all the air is
released and
some of it passes into the line, causing a build-up of air pressure and
ultimately the
creation of an air lock.
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In order to cope with the situation wherein sudden large quantities of air
appear
in the line and have to be released, the so-called 'kinetic valve' is used.
This valve has a
relatively large aperture through which large quantities of air can be rapidly
and
effectively vented. However, with such kinetic valves, once the housing
thereof has
filled with liquid and the float has been pressed against the large aperture
so as-to seal it,
the valve will only reopen once the pressure in the housing has dropped to
atmospheric
pressure and, in consequence, the kinetic valve cannot be used for the
continuous
release of small amounts of air.
In view of these limitations on the respective use of the automatic and
kinetic
valves, so called 'combined valves' have been designed which effectively
consist of a
kinetic valve and, superimposed thereon, an automatic valve. With such
combined
valves, continuous release of relatively small amounts of air throughout
operation take
place through the automatic valve, whilst sudden bursts of large quantities of
air are
released through the kinetic valve.
US Patent Serial No. 4,770,201 discloses in its abstract a fluid flow valve
such
as a faucet or air-purge valve comprising a housing having defined therein a
fluid
through-flow aperture with a valve seating formed in the housing and bounding
said
aperture. A flexible closure membrane is secured at one end to the housing and
is
adapted to be biased, under fluid pressure in the housing, against the valve
seating so as
to seal the aperture. Membrane displacing means are secured to an opposite end
of the
membrane so that displacement of the displacing means in a first sense
progessively
detaches successive transverse portions of the membrane from the seating so as
to open
the aperture while displacement of the displacing means in an opposite sense
allows for
the membrane to become sealingly biased against the seating.
US Patent Serial No. 6,145,533 discloses in its abstract an air release valve
comprising a housing having a fluid inlet and a fluid outlet, a valve plate
within the
housing between the inlet and outlet, the valve plate having a pair of
apertures; a valve
seal assembly including a seal engageable with the valve plate overlying the
apertures; a
float located in the housing upstream of the valve plate and connected to the
seal, the
float displaceable between first and second positions in the housing such that
displacement of the float in one direction opens the apertures, the float
having a tapered
end remote from the seal, the tapered end having a truncated substantially
flat bottom
surface and a groove extending across the flat bottom surface.
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US Patent Serial No. 7,011,105 discloses in its abstract a valve with a
housing
connectable to the pipeline or vessel. The housing has a first outlet venting
to
atmosphere and a control chamber which is exposed to internal pressure in the
housing
via a control chamber inlet. A first valve closure can move to open and close
the first
outlet. This valve closure is exposed to control chamber pressure tending to
move it to
close the first outlet and to internal housing pressure tending to move it to
open the first
outlet. When the housing is pressurized the first valve closure is maintained
in a closed
position by virtue of an unbalanced pressure force acting on it that is
attributable to
exposure of the valve closure to atmosphere through the first outlet. There is
also a
control chamber outlet from the control chamber to atmosphere. This outlet is
larger
than the control chamber inlet. The valve also incorporates a float in the
housing which
is arranged to be buoyed up by liquid entering the housing from the pipeline
and a
second valve closure carried by the float which is arranged to open and close
the control
chamber outlet in response to movement of the float caused by variations in
the level of
liquid in the housing. Downward movement of the float in response to a drop in
liquid
level in the housing, attributable to accumulation of air in the housing,
causes the
second valve closure to open the control chamber outlet. This allows the
control
chamber to vent to atmosphere. The pressure in the control chamber drops
relative to
the internal housing pressure and creates an unbalanced pressure force on the
valve
closure which causes it to open the outlet. The housing can then vent to
atmosphere via
the outlet.
It is an object of the present invention to provide an alternate flow-control
valve
of the combined type, with some improved features.
SUMMARY OF THE INVENTION
The present invention offers a cheep yet reliable valve which combines a
kinetic
stage valve for facilitating fluid flow at substantially high rate, and an
automatic stage
valve for substantially low flow rate. The device according to the present
invention has
the advantages of a large devise yet it is more compact in size and cheep in
manufacture.
According to the present invention there is provided a gas purge valve
comprising a housing formed with a fluid inlet and a fluid outlet, said fluid
outlet
bounded by a kinetic valve seating, and a sealing assembly comprising a float
member
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coaxially displaceable within the housing, and a sealing cap coupled to said
float
member; the sealing cap being axially displaceable with respect to the float
member
between a first position in which it conjoins the float, and a second position
in which it
departs from the float; said sealing cap formed at an outside face thereof
with a kinetic
seal fitted for sealing engagement of the kinetic valve seating, and an
automatic valve
aperture formed in the sealing cap and bounded by an automatic valve seating;
and an
automatic sealing member articulated to the float member for sealing
engagement of
the automatic valve seating.
The valve according to the present invention has one or more of the following
featuring characters:
= Alternatively, or in combination, the seal for the sealing cap may be
fitted in the valve body.
= The float member and the sealing cap articulated thereto, at the first
position at least, form together an aerodynamic capsule-like shape;
= The gas purge valve and its components are substantially symmetrical
about a longitudinal axis thereof;
= The sealing cap, at its second position, forms a space extending between
a top surface of the float and a bottom surface of the sealing cap. By a
particular embodiment this space is sealed at the said second position;
= At high flow rates within the valve there is formed a low-pressure zone
resulting in attachment forces acting between the float and the sealing
cap so as to retain them at their articulated position;
= The automatic sealing portion of the sealing assembly is axially
displaceable within the housing and the configuration is such that it is
axially displaceable within the kinetic sealing portion which is axially
displaceable within the housing;
= The automatic sealing member is in the form of a flexible strip
articulated to the float member at least at one end thereof;
= According to a particular design the automatic sealing member is in the
form of a strip of resilient material secured to the top portion of the float
at an inverted U-like shape, wherein at the second position thereof the
resilient strip is axially deformed into sealing engagement with the
automatic valve seating, to thereby seal the automatic valve aperture;
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= By modifications of the invention, the seal is connected at one end to the
float and at the other end to the sealing cap, or the two ends of the seal
are coupled to the float, or only one end is coupled to the float and the
other end is loose;
= There is provided a support member under the inverted U-like shaped
sealing strip to prevent its buckling upon deformation and also to assist
in sealing at low pressure;
= One of the automatic sealing member and the automatic valve aperture
are offset with respect to a longitudinal axis of the housing, thus giving
rise to a non-homogenous pealing pattern of the automatic sealing
member;
= According to some particular features of the valve, the housing is
designed with one or more of the following features:
o The housing is made of a single element integrated with the
kinetic valve seating;
o A coupling for fitting to a fluid line is integrated at the inlet of the
housing. The coupling is for example an internal/external
threading, bayonet coupling, a flange for coupling with a band,
etc.;
o The sealing assembly may be inserted as a whole through the
inlet port of the housing having an aperture corresponding with a
nominal diameter of the devise, though it may be assembled
within the housing too;
o The hosing is devoid of any static components apart for a flow
regulator inserted intermediate the inlet port of the housing and
the float member, said flow regulator supporting the float
member at its lowermost position;
o The housing is a substantially straight body without any major
undercutting, i.e. the interior diameter of the housing is uniform;
= The simple configuration of the housing renders it feasible to be
manufactured of molded plastic material;
= According to some particular designs the following geometrical ratios
exist:
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o DA/D,, > 0.32
where DA is the fluid outlet diameter (the 'kinetic seating' diameter)
and Dõ is the nominal diameter of the threat of a pipe coupled to the
valve;
o Doõt<Dn+28mm
where Dout is the maximal external diameter of the.housing.
According to an embodiment of the invention, an outlet deflector is fitted
over
the fluid outlet of the housing. Typically said deflector is fitted with a
protective screen
against dirt, insects and vandalism. Said deflector may be integrated with the
body.
According to a variation of the invention there a one-way stopper is fitted
within
the deflector, over the fluid outlet, to thereby restrict fluid flow in an
outwards direction
only, i.e. to prevent fluid ingress into the housing via said fluid outlet.
Optionally the
stopper is biased into sealing engagement of the fluid outlet and will
displace into an
open position upon fluid egress through the fluid outlet. Thus, the valve may
serve for
the following functions:
= Allowing air ingress and prohibiting egress;
= Allowing air ingress and only partial air egress;
= Allowing air egress and prohibiting air ingress.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to understand the invention and to see how it may be carried out in
practice, several embodiments will now be described, by way of non-limiting
examples
only, with reference to the accompanying drawings, in which:
Fig. 1 is a perspective general view of a valve according to an embodiment the
present invention;
Fig. 2 is a perspective, longitudinally sectioned view of the valve of the
present
invention;
Figs. 3A and 3B illustrate a sealing cap used in the valve according to the
invention, at a top perspective view and a bottom perspective view,
respectively;
Fig. 4 is a top perspective view of a float closure used in the valve
according to
the invention;
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Figs. 5A to 5C are longitudinal sections illustrating the valve according to
the
invention at a fully opened position, a fully closed position and at an
automatic open
position, respectively;
Fig. 6A is a perspective view of a valve according to an embodiment of the
invention, fitted with a one way stopper;
Fig. 6b is a bottom perspective view of the stopper seen in Fig. 6A; and
Figs. 7A and 7B are representations of modifications of the valve's housing
coupling arrangements.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
Attention is first directed to Figs. 1 and 2 of the drawings illustrating a
gas purge
valve in accordance with the present invention and generally designated 10. It
is noted
that the valve in Fig. 1 is fitted with a threaded coupler 12, absent in Fig.
2, as will be
discussed hereinafter in further detail.
The valve 10 comprises a generally cylindrical housing 14 formed with a
coupling portion 16 which in the present embodiment is internally threaded at
18, and is
formed with a fluid inlet 20 and a fluid outlet 24, the latter formed at a
bottom face
thereof with a kinetic valve seating 26.
Several axial ribs 28, radially extending are provided, two of which are seen
in
Fig. 2, and serve for the purpose of restricting displacement of a sealing
assembly 30 to
axial displacement within the housing and preventing rotation thereof.
The sealing assembly 30 comprises a float member 32 composed of a cylindrical
bottom portion 34 sealed by a float closure member 38, together defining a
sealed float
member. The float is formed with axial recesses slidingly displaceable over
the axial
ribs 28.
The sealing assembly further comprises a sealing cap 40 articulated to the
float
closure 38, as will be explained hereinafter. The sealing cap 40 is formed
with an
automatic valve aperture in the form of slit 44 and a kinetic disk-like seal
48 for sealing
engagement with the kinetic valve seating 26 at the fluid outlet 24 of the
housing 14.
The automatic valve aperture 44 is bounded, at its bottom face with an
automatic
valve seating 50 sealingly engageable by an automatic sealing valve member 54,
in the
form of a strip-like resilient material, secured on the top portion of the
float closure 38.
In the embodiment as illustrated in Fig. 2 and as clearly illustrated in Fig.
4, the top
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closure 38 comprises two receptacle grips 56 for coupling said automatic
sealing valve
member 54 however ret6ainig its flexibility. As can be seen in Fig. 5C, when
the valve
is at the so-called 'automatic open position' the automatic sealing valve
member 54 is
un-deformed and assumes a substantially U-like shape. However, upon sealing
engagement with the automatic valve seating 50 (Figs. 2, 5A and 5B) the
automatic
sealing valve member 54 is deformed to ensure full contact sealing of the
automatic
valve seating 50.
In order to ensure that the automatic sealing valve member 54 does not buckle
at
its deformed position, a support member 58 extends from the sealing cap 40,
under the
U-like shaped sealing strip, such that at the sealing position (Figs. 2, 5A
and 5B) it
biases the resilient automatic sealing valve member 54 into sealing contact
with the
automatic valve seating 50.
It is further noted, that in Fig. 4, that the float closure 38 is formed with
two
lateral projections 61 (one of which is seen) radially projecting therefrom,
for snap
engagement within recessed aperture 62 formed in the sealing cap 40, thereby
providing
for some axial freedom of the sealing cap 40 with respect to the assembled
float unit 32
however, ensuring that downward displacement of the float unit 32 entails
retraction of
the sealing cap 40 to thereby open the kinetic valve sealing as will be
discussed in detail
hereinafter.
The sealing cap 40 is axially displaceable with respect to the float member
assembly 30 between a first position in which it conjoins the float assembly
32 and
together assume an aerodynamic capsule-like shape (Figs. 2, 5A and 5B) and a
second
position, in which the sealing cap 40 departs from the float closure 38,
though remains
articulated thereto as explained hereinafter in connection with lateral
projection 62 and
slidingly articulated within recesses 62.
As can further be noted, for example in Fig. 2, the assembled float and
sealing
assembly are supported within the housing by a flow regulator 68 which in turn
is
retained within the inlet 20 of the housing 14 by an annular shoulder 70
snappingly
received within a corresponding shoulder 72 formed in the inlet of the
housing. The
flow regulator 68 serves also to support the float and to adjust air flow
between the float
bottom and the regulator, so as to give rise to a low pressure zone assist in
marinating
the float at the open stage during kinetic air venting.
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As can further be seen in the drawings, the valve 10 is fitted with an outlet
deflector 80, snappingly mounted over the fluid outlet 24 of the housing. The
deflector
80 is fitted with an outlet spout-like portion 82 to which a pipe extension
may be fitted
(not shown). A protective screen 84 is integrally fitted within the outlet
reflector 80,
against dirt, insects, and vandalism.
The structure of the valve 10 in accordance with the present invention as
illustrated in the drawings, has several unique features. For example, the
housing 14 is
made of a single element integrated with a kinetic valve seating 26 and the
design is
such that the housing is a substantially straight body without any
undercutting i.e. the
interior diameter of the housing is substantially uniform, allowing for its
simple
manufacture e.g. by molding plastic material.
According to the design of the valve 10, the sealing assembly 30 is inserted
into
the housing 14 as a whole, through the inlet port 20 of the housing 14 having
an
aperture corresponding with a nominal diameter of the housing D.
According to some particular designs, the following geometrical ratios exist
in
the housing.
o DA/Dr, > 0.32
where DA is the fluid outlet diameter (the 'kinetic seating' diameter)
and Dn is the nominal diameter of the threat of a pipe coupled to the
valve;
o Dout< Dn+28mm
where Doõt is the maximal external diameter of the housing.
As further noted in the drawings, the gas purge valve 10 and its components
are
substantially symmetrical about a longitudinal axis of the valve being the
result of the
simple structure of the device.
Figs. 5A to 5C illustrate different operative positions of the valve. In Fig.
5A the
valve 10 is in the so-called 'fully opened position', wherein the valve
assembly 30 rests
on the flow regulator 68 and wherein the sealing assembly 30 is at its so-
called first
position namely wherein the sealing cap 40 rests over the float closure 38,
such that the
kinetic valve fluid outlet 24 is entirely open, allowing for the discharge of
substantially
large amounts of gas therethrough. Gas flow is facilitated through a gap
existing
between the float assembly 32 and the inner walls of the housing 14. The
capsule-like
design of the float and sealing assembly are such that at high. flow rates
within the
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valve, there is formed a low pressure zone designated -at 88 and resulting in
attachment
forces acting between the float assembly (namely the float closure 38) and the
sealing
cap 40 so as to retain them at their articulated, adjoining position.
Fig. 5B illustrates a position in which liquid flows into the housing 14
through
the fluid inlet 20, resulting in buoyancy forces acting on the float assembly
32, urging
the float and the articulated sealing assembly into tight sealing engagement
of the
kinetic fluid outlet 24 by means of kinetic seal 48 sealingly engaged with
kinetic valve
seating 26 and by sealing engagement of the automatic sealing valve member 54
with
the automatic valve seating 50 of the automatic valve aperture 44.
The space extending between the sealing cap 40 and the float closure 38 is
substantially closed and by an embodiment of the invention this space may be
tightly
sealed, e.g. by the provision of a sealing ring on either or both of the
mating portions of
the sealing cap and the float closure, respectively.
In Fig. 5C the valve 10 is illustrated in a position in which liquid level
within the
housing 14 decreases, allowing for descending of the float assembly 30 to
thereby
progressively detach the automatic sealing valve member 54 from the automatic
valve
seating 50 of the automatic valve aperture 44 whereby gas may now bleed
through the
automatic valve aperture 44 and facilitate in further detachment of the
automatic sealing
valve member into full disengagement resulting in further descending of the
float
assembly and entailing corresponding descending and disengagement of the
sealing cap
40 so as to open the kinetic fluid outlet as in the position of Fig. 5A.
It is noted that the automatic sealing portion of the sealing assembly is in
fact
axially displaceable within the housing and a configuration is such that it is
axially
displaceable within the kinetic sealing portion which is in turn axially
displaceable
within the housing.
Fig. 6A illustrates a valve in accordance with a modification of the invention
the
difference being in the provision of a one-way stopper 90 formed with a stem
portion 92
slidingly received within a receptacle 94 of the deflector 80 and comprises a
sealing
portion 96 fitted for sealing engagement with the automatic fluid outlet 24.
The arrangement is such that the stopper is a one-way valve normally biased
downwards under its self-weight into sealing engagement of the outlet 24.
However,
owing to its light weight, it will displace upwardly (not shown) to disengage
from the
outlet 24 and facilitate free flow through the kinetic fluid outlet 24.
According to a
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modification, there may be a biasing member the force of which being
controllable so as
to determine the opening force required for displacing the valve into its open
position.
Turning now to Fig. 7A, there is illustrated an embodiment of the invention
wherein the coupling portion 16' of the housing portion 100 is fitted with an
external
threading 102 for coupling within a corresponding threaded pipe portion (not
shown). In
the embodiment of Fig. 7B, the coupling portion 16" comprises a laterally
extending
flange 106 for coupling to a corresponding flanged tube member 108 by means of
a bolt
and knot 112 or by means of a brace member 116.
According to still an embodiment of the invention, one of the automatic
sealing
member and the automatic valve aperture are off-set with respect to a
longitudinal axis
of the housing, thus giving rise to the non-homogeneous pealing pattern of the
sealing
member.
While there has been shown a preferred embodiment of the invention, it is to
be
understood that many changes may be made therein without departing from the
spirit of
the invention.
