Gas purge valve

A gas purge valve comprising a housing fitted with an inlet port being in flow communication with a liquid outlet port, and at least one gas outlet member, a gas flow barrier associated with the liquid outlet port, a float member displaceable within the housing between a first position adjacent the inlet port and a second position adjacent the gas outlet The at least one gas outlet is fitted with an inlet prohibiting valve, and is sealingly engageable by a flexible sealing member articulated to the float member. Buoyant displacement of the float member into the second position entails sealing of the at least one gas outlet by the flexible sealing member.

FIELD OF THE INVENTION

The present invention generally relates to gas purge valves and more particularly it is concerned with air release valves suitable for discharging gas at a wide range of pressure and flow rate, including substantially low gas pressure and low flow rate.

BACKGROUND OF THE INVENTION

Air purge valves are generally fitted to liquid conduits such as, for example, mains distribution lines or sewage distribution conduits 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. Air flowing through a liquid supply line may, apart from causing mechanical damage to equipment fitted on the conduit, also cause malfunctioning of different devices such as flow meters, valves and the like.

Two different kinds of gas puree 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 outlet aperture. In the course of normal operation with the flow of liquid through the conduit, the housing falls with liquid and the spherical float is forced upwardly against the outlet aperture sealing the same. However, when 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. Then, the housing again fills with liquid and the aperture is sealed by the float.

In a first kind of air purge valve, known as the automatic kind, the outlet aperture is of relatively small dimensions and the float is displaced downwardly responsive to air presence 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 kind cannot cope with situations wherein large quantities of air have to be vented and when such a situation arises, not all the air is released and some of it passes into the line, potentially giving rise to an air lock.

The second kind of air purge valve is used in order to cope with the situation wherein sudden large quantities of air appear in the line (e.g. upon filling, an empty conduit system) and have to be discharged (released from the conduit, for example to the atmosphere). This type of valve is the so-called kinetic valve. This valve has a relatively large aperture through which large quantities of air can be rapidly and effectively vented. However, with such a kinetic valve, 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 particular when flowing at high pressure.

Gas purge valves combining the features of the automatic and the kinetic types have been designed, which effectively consist of a kinetic valve and, superimposed thereon, an automatic valve. With such combination-type 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. Such combined valves are nevertheless of relatively bulky and expensive construction.

U.S. Pat. No. 4,770,201 to Zakai, discloses a combined type of gas purge valve comprising a housing having 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 progressively 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.

U.S. Pat. No. 4,082,106 to Butcher discloses a valve for automatically collecting and venting gases included in flowing liquid. The valve has a chamber in which air collects, a float in the chamber and a vent valve at the top operated by the float to vent the chamber when the liquid level falls. The vent valve has a convex or concave seat with apertures therein and is sealed by a flexible diaphragm which is peeled progressively from the seat to open the valve. The diaphragm may be annular and fixed at its outer periphery, being flexed by a coupling at its center, or may be fixed at the center and flexed by a coupling at its periphery.

It is an object of the present invention to provide a new and improved gas purge valve having a compact and inexpensive structure. In particular, the gas purge valve according to the present invention is suitable for discharging of significantly low amounts of gas, i.e. gas flowing through a conduit at significantly low pressure and at a low flow rate. However, the device will also discharge of gas flowing at high flow rate and at higher pressure. Still a further object of the present invention is to provide a gas purge valve of the specified type, suitable for mounting to liquid conduits with varied configurations such as a through-flow device or an appendix type.

SUMMARY OF THE INVENTION

The present invention calls for a gas purge valve which is particularly but not exclusively adapted for fitting on a liquid supply conduit, upstream of a liquid flow device, e.g. a flow meter (water meter). According to one application, the gas purge valve according to the invention is fitted for mounting as a through-flow device, i.e. on a vertical conduit segment, where liquid flows through the valve housing. According to an alternative application the gas purge valve is fitted on a non-vertical conduit segment, e.g. a generally horizontal conduit, where liquid does not flow through the valve housing.

According to the present invention there is provided a gas purge valve comprising, a housing fitted with an inlet port being in flow communication with a liquid outlet port and at least one gas outlet; a gas flow barrier associated with the liquid outlet port; a float member displaceable within the housing between a first position adjacent the inlet port and a second position adjacent the gas outlet; said at least one gas outlet fitted with an inlet prohibiting valve, and being sealingly so engageable by a flexible sealing member articulated to the float member, whereby buoyant displacement of the float member into the second position entails sealing of the at least one gas outlet by the flexible sealing member.

According to a particular embodiment of the present invention, the gas flow barrier is a normally closed one-way valve, which responsive to a pressure exceeding a predetermined magnitude admits liquid flow in direction from the inlet port towards the outlet.

According to a first application of the invention, the valve is fitted on a non-vertical conduit segment (appendix-type mounting), wherein a liquid flow path extends between the inlet port and the outlet port, and where the housing is formed with an inlet duct extending intermediate the inlet port and a float receiving space of the housing.

According to a second application of the invention, referred to as a so-called through-flow gas purge valve, the liquid flow path extends through the housing. Accordingly, the outlet port and the housing coaxially extend-along a vertical axis of the housing. In accordance with a particular embodiment of this application, the outlet port accommodates the gas flow barrier.

Occasionally, the valve may malfunction, e.g. as a result of sand, dirt, etc. entering the valve. By a further aspect of the invention, the valve is thus provided with a user-interruptible inactivating arrangement.

According to one inactivating arrangement of the present invention, the housing is formed with an inlet duct extending intermediate the inlet port and a float receiving space of the housing, where flow through said inlet duct is user-interruptible to thereby inactivate the valve. In a valve of the first application, inactivating the valve does not interrupt fluid flow between the inlet port and the outlet port. In a valve of the second application, inactivating the valve permanently stops liquid flow between the inlet port and the outlet port. According to one embodiment, interruption is obtained by forcefully introducing a tool through a breakable wall of the inlet duct, said tool serving also for blocking flow through the inset duct.

According to a different inactivating arrangement the gas outlets open into an outlet chamber formed under a top cap formed with one or more discharge openings. The chamber is fitted with one or more sealing members corresponding with the discharge openings of the top cap, where inactivating the valve is achieved by aligning the one or more discharge openings with the one or more sealing members so as to seal the discharge openings.

According to this arrangement, either the top cap is rotatable over the housing or the sealing members may be fitted over an accessible rotary member.

An advantage of this arrangement is that the valve may be inactivated and easily reactivated on demand.

The housing comprises at least one and preferably at least a pair of gas outlet ports, each bounded by a sealing seat sealingly engageable by a corresponding sealing portion of the sealing member. Furthermore, at least one of the gas outlet ports comprises a first outlet aperture and a second outlet aperture bounded by first and second valve seatings, respectively; and where displacement of the float member from the second to the first position, progressively detaches the sealing member initially from the first valve seating so as to open initially said first outlet aperture and subsequently from said second valve seating so as to open subsequently said second outlet aperture, whilst buoyant displacement of said float member from said first position to said second position allows for said float member to become sealingly biased against said seatings.

According to the second application of the invention, a liquid flow path extends through the housing essentially vertically between the inlet port and the outlet port.

It is desirable for a valve according to either of the applications of the present invention., to be tamper-proof, so that it is not possible to override it and “steal” water. Accordingly, a cap is fitted over the valve housing, to thereby prohibit tampering with the valve through the gas outlets.

According to an embodiment of the first application of the invention., the inlet port and the liquid outlet port are integrally formed with the housing, where a liquid flow path extends between the inlet port and the outlet port. According to one particular embodiment, the housing is made of plastic material and the flow path extends through a uniform metallic coupling member.

Preferably, a first portion of the sealing member, adapted to bear against the first valve seating, is of lesser rigidity than a second portion, adapted to bear against the second valve seating. To increase sealing engagement of the sealing member with the respective seatings of the gas outlets, the second portion of the sealing member comprises a cushioned sealing portion engageable by a corresponding biasing portion of the float member biasing it into sealing engagement with the outlet valve seatings.

The cushioned sealing portion of the sealing member and the biasing portion of the float member are equally inclined with respect to an axis of displacement of the float member. According to one particular design, the cushioned sealing portion of the sealing member is formed with a bulge engageable by the corresponding biasing portion of the float member, to thereby give rise to reactionary forces acting along a line normal to a sealing surface of the first portion of the sealing member.

To increase the sealing force acting on the sealing member when it is engaged with the seatings of the gas outlets, one of the first portion of the sealing member and the corresponding second valve seating is indented with respect to the other one of said first portion of the sealing member and the corresponding second valve seating, to thereby increase the effective sealing area.

According to a particular embodiment of the invention, the valve is an inexpensive, disposable device, fitted on a water supply line, adjacent before a water flow meter.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

Attention is first directed toFIGS. 1 and 2illustrating a first embodiment of a gas purge valve in accordance with the present invention generally designated20, illustrated in.FIG. 1Ain a so-called open position, namely an air releasing position and inFIG. 2Aillustrated in a so-called closed position, as will become apparent hereinafter.

The embodiment ofFIGS. 1 and 2illustrates a structure suitable for mounting on a non-vertical conduit segment, e.g. a generally horizontal conduit. The valve20comprises a housing22which is a cylindrical structure extending essentially vertical from a liquid coupling member24, formed with an inlet port28and an outlet port30with a flow path32(FIG. 2A) extending therebetween. In the present example, housing22is integrally formed with the liquid coupling member24, manufactured of molded plastic material, with suitable reinforcement structural ribs. It is however appreciated that this is a mere example and the housing22and liquid coupling member24may be separate units coupled together. The valve of the specified type is typically suitable for mounting in front of a water flow meter (not shown), but not necessarily restricted to this positioning.

Received within the liquid coupling member24, intermediate the inlet port28and the outlet port30there is fitted a gas flow barrier generally designated40in the form of a normally closed one-way spring biased valve, as will be explained hereinafter in more detail with reference toFIGS. 1B and 2B.

Housing22is formed with an essentially vertical float receiving space46being in flow communication with the flow path32via inlet duct48extending through a neck portion52. Axially displaceable within lie float receiving space46there is disposed a generally cylindrical float member50comprising two or more axial grooves53slidably engageable with corresponding axial ribs56(seen clearly inFIG. 8C) so as to ensure that the float member50performs only axial displacement and does not rotate within housing22. A gas outlet member62(best seen inFIGS. 3A and 3B) is fixedly fitted at an upper end of the housing22in a sealed snap-type connection. The gas outlet member62is formed with a plurality of gas outlets64and66as will be explained hereinafter in more detail with references toFIGS. 3A and 3B. The gas outlets64and66are sealingly engageable by a flexible sealing member generally designated70which is seen in more detail inFIGS. 4A and 4B.

Sealing member70is in the form of a strip of material comprising at its two remote ends a bulging portion72securely arrested within a suitable receptacle of the housing22and clamped by the gas outlet member62, as illustrated inFIGS. 1A and 2A. An aperture76is formed at a center portion of the sealing member72for engagement over a coupling bulge80of the float member50whereby axial displacement of the float member50entails displacement of the sealing member70between an open position as inFIG. 1Aand a closed, sealing position, wherein the gas outlets64and66are sealed by the scaling member, as inFIG. 2Band as will be explained hereinafter in more detail.

An inlet prohibiting valve member82, comprises two leaf-type sealing members84(FIGS. 1A,2A) adapted for sealing engagement over the gas outlets64and66thereby prohibiting ingress into the housing of gas, liquid, dirt, etc. InFIG. 1A, the inlet prohibiting valve member82is in its open position, i.e. allowing gas to escape through gas outlets64and66whilst inFIG. 2A, the inlet prohibiting valve member82is in the so-called closed position, thus prohibiting ingress into the float receiving space46. It is appreciated that the leaf-type sealing members84are normally in their closed position as inFIG. 2Aand are easily displaceable into the open position as inFIG. 1A, by the mere flow of gas through the outlets64and66. This effect is increased by imparting the leaf-type closures84with a pre-stressed deformation by projections88formed in a top cover92of the valve pressing against respective portions of the inlet prohibiting valve member82.

Top cover92is snapingly mounted over the housing22leaving an interstice96therebetween constituting a gas outlet flow which is tamper-proof, i.e. does not allow access to manipulate the float member and to override the valve so as to allow liquid flow through the interstice96(merely for the purpose of stealing water).

Turning now also toFIGS. 1B and 2B, detailed reference will be made to the gas flow barrier40which is coaxially fitted within the liquid coupling member24between the inlet port28and the outlet port30. As already mentioned hereinbefore, the gas flow barrier40is in the form of a normally closed one-way valve, comprising a sealing member100fitted with a sealing ring102and being coaxially displaceable within the liquid coupling member between a closed position (FIG. 1B) in which the sealing ring102sealingly bears against a sealing seat106, and an open position (FIG. 2B) in which liquid flow between the inlet port28and the outlet port30is admitted. Sealing member100is fitted with a stem110fitted at an inlet end thereof with a guiding member112slidingly displaceable within the inlet port28. A biasing spring member116bears at one end against said guiding member112and at an opposed end thereof against an annular rib121of the liquid coupling member24, thereby biasing the sealing member100into the normally closed position as inFIG. 1B.

The arrangement is such that liquid entering the liquid coupling member24through inlet port28applies sufficient force on the sealing member100so as to displace it into the open position (FIG. 2B) to facilitate liquid flow through the flow path32, i.e. in the direction between the inlet port28and the outlet port30along a flow path represented by arrows111. However, gas flowing through the inlet port will not displace the gas-flow barrier40into the open position and wig thus continue flow through the duct48and into the float receiving space46within housing22along a flow path represented by arrows113(FIG. 1B). It is appreciated that in this position the gas outlets64and66and the inlet prohibiting valve member82open even under mild flow pressure of the flowing gas.

As long as only gas flows through the float receiving space46, the float member50remains in its bottom position, as inFIG. 1A, retaining the sealing member100in the open position whereby gas can easily escape through gas outlet outlets64and66and then to the atmosphere through interstice96extending between the housing22and the top cap92.

The flow path of gas through the valve in its so-called open position is represented inFIG. 1Aby solid arrows.

In the event of liquid flowing through the inlet port28, the gas flow barrier40displaces into the open position (FIGS. 2A and 2B), allowing liquid flow to pass through the flow path32between the inlet port28and the outlet port30, as illustrated by dashed arrows (FIG. 2A). Some of the liquid, however, enters the float receiving space46applying buoyancy forces on the float member50, resulting in its immediate displacement into its uppermost position as in.FIG. 2A, resulting in turn in sealing displacement of the flexible sealing member70against the gas outlets64and66, sealing the valve and preventing liquid egress through the gas outlets64and66. It is noted that in this position the inlet prohibiting valve member82is in its normally closed position with flaps84sealingly bearing against the openings of the gas outlets64and66.

Presuming that some gas is entrapped within the piping it will eventually accumulate within the float receiving space46, eventually causing the float member50to descend, entailing initially pealing of the valve member from the gas outlets to allow escape of small amounts of gas (as will be explained in more detail hereinafter), or completely descending to the downward position of the float member50(FIG. 1A) where significant amounts of gas can escape through the gas outlets64and66until the float member50is again displaced into its uppermost position under buoyancy forces applied thereto by liquid entering the float receiving space46.

Turning now to some particular matters, further attention is now directed toFIGS. 4A and 4Billustrating the sealing member generally designated70. Sealing member70comprises two cushioned sealing portions120, each formed at a bottom face thereof with a projecting bulge124and at a top face thereof with a rectangular indention128. The cushioned sealing portions120are relatively rigid, i.e., non-flexible. Contrary thereto, intermediate the sealing portions120there are two resilient sealing zones130imparting the sealing member70flexibility.

Turning toFIG. 31, which is a bottom view of the gas outlet member62, it is noticed that the gas outlet64(referred to in the claims as a first outlet aperture) differs from the gas outlets66(referred to in the claims as a second outlet aperture) in that it comprises an extension or extended slit portion67bounded by a first valve seating180where the outlets66are bounded by a second valve seating182, said first and said seatings being in the form of an essentially flat surface. The extended slit portion67of the first gas outlet64is noticeable also inFIGS. 3A,5and6. It is appreciated that an extended slit portion may be formed at one or both sides of the gas outlet member62and that more then one gas outlet may be formed with an extended slit portion.

With further reference toFIGS. 5 and 6, it is noticeable that the extended slit portion67(extending from of gas outlet66) is engageable by the corresponding resilient portion130of the sealing member70whilst the larger gas outlets64are sealingly engageable by the rigid sealing portion120of the sealing member70. It is further noticed inFIG. 5that the second valve seatings182, represented inFIG. 5by a dashed line, is engageable by the rigid sealing portion120of the sealing member70and in particular it is noted that the indented portion128corresponds with the second valve seatings182though it does not cover the first outlet aperture's extended slit portion67of outlet66.

The above arrangement has several advantages. First, the resilient sealing portion130of the sealing member70is peelable from the extended slit portion67, thus constituting a so-called automatic gas purge valve where insignificant amounts of gas, i.e. bubbles, may be easily discharged from the valve housing on the one hand, and on the other hand, the progressive detachment of the sealing member, initially from the first valve seating180first to initially open the extended slit portion67renders it easier to subsequentially detach the rigid sealing portion120from the second valve seating182. This renders a valve in accordance with the present invention the qualities of a so-called combined gas discharge valve, namely a kinetic valve suitable for discharging large amounts of gas and an automatic valve for discharging small amounts of gas also when flowing at low pressure and at low flow rate.

A second advantage of the above structure is that the effective sealing area between the rigid sealing portion120and the second valve seating182(bordering the gas outlet64) is significantly increased. In practice, effective sealing area is the sectional area of the indented portion128of the sealing member70. In the absence of the indented portion, the effective sealing area would be the sectional area of the gas outlets64and66which is significantly less than, that of the indented portion128. However, it is appreciated that rather than forming the indented portion128in the sealing member70, the indentation may be formed around the valve seatings formed at the gas outlet member62.

With finder reference toFIG. 6, it is noticeable that sealing of the gas outlets64and66is obtained upon displacement of the float member50into its upper position whereby the sealing member70is pulled into its sealing position. However, in order to ensure tight sealing of the gas outlets64and66, the float member50is formed at an upper end thereof with two tapering surfaces196inclined in correspondence with the geometry of the valve seatings182of the gas outlet member62. The arrangement is such that upon descending of the float member50, the inclined surfaces196encounter the bulges124of sealing portions120of sealing member70, thereby tightening the sealing effect of the sealing portions120against the second valve seatings182. This arrangement ensures that the rigid sealing portions120are displaced into sealing engagement with the second valve seatings182at parallel relation albeit encountering surfaces196of float member50not at right angles.

InFIGS. 1 and 2, the liquid coupling member24is made integrally with the housing22, molded of plastic material.FIGS. 7A and 7Billustrate an alternative design wherein a liquid flow path130extends between an inlet132and an outlet134of a metallic insert tube segment138securely fixed within the liquid coupling member24′ by a fastening nut142. In this embodiment, the liquid coupling member24′ is integrally molded with the housing (not shown). The tube segment138has a hexagonal portion146snugly received within a corresponding hexagonal inlet opening148of the liquid coupling member24′ to thereby ensure that a liquid duct152of the metal tube segment138coincides with the inlet duct48′ of the liquid coupling member24′ (FIG. 7B). However, other arrangements are possible as well for ensuring correct assembly of the metallic tube segment within the coupling member. A gas flow barrier40′ is received within the flow path130, similar to the arrangement disclosed in the previous embodiments, with reference toFIGS. 1 and 2. Suitable sealing rings156and158render the assembly leak-proof.

The inlet port is formed with a coupling by means of internal threading162and the outlet port134is formed with a coupling by means of external threading164. The metallic tube segment138is of increased durability as compared with plastic components.

Further attention is now directed toFIGS. 8A–8Cillustrating a valve casing generally designated200and integrally comprising a valve housing202and a liquid coupling member204. The valve200may be of the type disclosed in connection withFIGS. 1 and 2or of the type disclosed in.FIGS. 7A and 7B, namely fitted with a metallic coupling insert. At times, it may be necessary to stop the action of the valve, e.g. in case of malfunction thereof upon entering of dirt into the region of the valve seatings etc. It may also be required to inactivate the valve200in case the inlet prohibiting valve member82fails to operate when gas enters the piping system or in case the valve200becomes immersed in mud (e.g. in the case of a flood or some other environmental disaster) where dirt may then enter the public water supply system.

Accordingly, the casing200is fitted at the neck portion208with a slot212extending at two sides of the inlet duct48′ such that a thin wall portion216remains. Preferably, the wall216is formed with a V-like notch220serving for concentrating mechanical stress, as will be apparent hereinafter. A chisel-like tool224is snugly received within the groove212at a fit tolerance, so that it does not spontaneously displaced from or within the groove212. A front tip226of the chisel tool224is pointed, such that in the assembled position (FIG. 8C) the pointed tip226faces the notch220of wall216.

The arrangement is such that when it becomes necessary to inactivate the flow through the valve200, the tool224is forcefully pushed, e.g. by the aid of a hammer, etc. against the wall216, breaking the wall and extending through the inlet duct48′ to discontinue flow through the inlet duct. It is appreciated that the tight tolerance within the groove212ensures a leak-proof and sealing engagement of the flat surfaces of the chisel tool224with a peripheral rim228(FIG. 813) of the inlet duct48′. Typically, the user interruptible process is irreversible, namely, it is not possible to mend the broken wall portion216and it is required to replace the entire valve200.

Further attention is now directed toFIGS. 9A and 9Bof the drawings illustrating a different embodiment of the invention suitable for vertical installation such that liquid flow through the housing is enabled whilst functioning as a gas purge valve.

For the sake of clarity, those components which are of similar design and function as in the previous embodiment ofFIGS. 1 and 2are given same reference numbers shifted by300.

The principle components and function of the valve300are principally similar to those disclosed inFIGS. 1 and 2with the main difference that liquid ingresses the valve through inlet port302and egresses through outlet port304such that the flow path extends within the housing, between the inlet port302and the outlet port304. In accordance with this particular design, the inlet port302and the outlet port304are coaxial with the flow path extending through the float receiving space346. Furthermore, in the present embodiment a gas flow barrier340, is similar to gas flow barrier40disclosed inFIGS. 1 and 2, though it is fitted at the outlet304which constitutes an integral part of the top cover392.

The valve300is useful in particular, but not necessarily restricted thereto, for mounting on a vertical piping segment, upstream a flow metering device. The valve300will allow liquid flow between the inlet and outlet ports302and304and will discharge gas entering through the inlet port302via the interstice396, even significantly small amounts of trapped gas (bubbles) at essentially low flow rate and at low pressure (0.3 atmospheres or less).

The valve300operates in a similar manner as the valve20of the previous embodiment, disclosed with reference toFIGS. 1 to 6. In the case of gas entering the float receiving space346, the float member350remains at its lowermost position (FIG. 9A) such that the gas outlets364and366remain open, allowing the gas to flow out of the housing322and to the atmosphere through interstice396between the top cap392and the housing322. The flow path of gas discharged through the valve300is illustrated inFIG. 9Aby solid arrows.

It is appreciated that the gas flow barrier340is of similar design as that illustrated inFIGS. 1 and 2, and in the position ofFIG. 9Ais closed by the biasing effect of a coiled spring316, thus preventing gas flow through the outlet port304.

In the event of liquid entering through inlet port302, the float member350ascends to its upper position as inFIG. 9B, entailing corresponding displacement of the sealing member370into sealing engagement thereof with the gas outlets364and366. However, the liquid pressure displaces the gas flow barrier340into its open position (FIG. 9) against the biasing effect of coiled spring316to thereby allow liquid flow through the outlet port304. Liquid flow path through the valve300is illustrated inFIG. 9Bby dashed arrows.

It is to be appreciated that the valve disclosed inFIGS. 9A and 9Bhas the same characteristics as of the valve disclosed in,FIGS. 1 and 2as far as sealing and un-sealing (detaching from the valve seatings). Namely, the valve is a combined valve, having the properties of a kinetic valve and of an automatic valve, rendering it suitable for discharging gas flowing at low flow rates and low pressure, as well as at high flow rates.

It is appreciated that the housing322may be formed at a lower end thereof, intermediate the inlet port302and the float receiving space346with an inactivating arrangement similar to that disclosed in connection withFIGS. 8A–8C.

To ensure correct mounting of a valve according to the invention, it is desired that the housing be formed with some indication indicating the flow direction, e.g. arrow199inFIG. 7A.

It is also to be noted that while the embodiments disclosed hereinabove illustrate a symmetric arrangement comprising a pair of gas outlets and a corresponding arrangement of the sealing member, it is also possible to design the valve in accordance with an embodiment of the invention (not shown), with a non-symmetric arrangement, i.e. comprising a single array of gas outlets and a sealing member formed with one resilient sealing portion and one rigid (non-pliable) sealing portion, however, retaining the combined function of the valve (integrated kinetic and automatic).

The pipe segment may be fitted with a one-way outlet valve, in replacement of the inlet prohibiting valve member82disclosed in the previous embodiments.

Further attention is now directed toFIGS. 10 to 12illustrating some modifications of the valve in accordance with the present invention. Turning first toFIGS. 10A and 10Bthere is illustrated a through-flow type valve generally designated400which operates in a similar manner as the valve in accordance with the embodiments ofFIGS. 1 to 7though with some modifications. For example, in the embodiment ofFIGS. 10A and 10Bthere is provided a metallic insert tube segment designated404which is snap-fitted within the liquid coupling member406, thus obviating fastening nut142as in.FIGS. 7A and 7B.

Furthermore, the gas discharge flow path is different and is now governed by a top cap410snap-fitted over the housing412though being rotatable thereabout. The top cap410clampingly arrests a gas outlet member416with a sealing O-ring418provided therebetween.

An outlet chamber420is formed between the top cap410and the gas outlet member416, said chamber420has a discharge opening422fitted with a screen426(best seen inFIG. 10A).

As can further be seen (FIGS. 10B,11A and11D) gas outlet member416is fitted with a resilient sealing member430mounted on a pair of stems432and sized for sealing engagement with the discharge opening422to thereby seal the outlet chamber420.

The valve400operates similarly as the valve disclosed hereinabove in connection withFIGS. 1 to 7, however, inactivation of the valve is now controlled by rotation of the top cap410between an operative, open position (FIG. 11A) and a closed, inactivated position. (FIG. 11B) where the sealing member430sealingly engages the discharge opening422formed in the top cap410. This arrangement is reversible such that the valve may be activated and deactivated as may be required. It is further desired that the top cap410be provided with suitable indicia, e.g. arrows436(FIG. 10A) and suitable wording if desired.

It is further appreciated that more than one discharge opening may be provided and accordingly a corresponding arrangement of sealing members is required first to sealingly engage the discharge openings.

FIG. 12shows another modification of the valve illustrated by a valve450fitted with a threading452for screw coupling to a liquid coupling member (not shown) and further fitted with a discharge nozzle456which in the case of an appendix-type valve may be coupled downstream. However, the inactivating mechanism in the embodiment ofFIG. 12is similar to the embodiment disclosed in connection with the embodiment disclosed in connection withFIGS. 10 and 11, i.e. by rotation of the top cap410.