WO2017031584A1

WO2017031584A1 - Demountable coupler valve for one-way kegs

Info

Publication number: WO2017031584A1
Application number: PCT/CA2016/050994
Authority: WO
Inventors: Chris RANDALL; Melanie KOBELKA; Chris HURLBURT; Levi KUTA; Chris Riemer
Original assignee: First Element Packaging Inc
Current assignee: Standard H2 Inc
Priority date: 2015-08-24
Filing date: 2016-08-24
Publication date: 2017-03-02
Anticipated expiration: 2018-02-24

Abstract

A two-stage stage coupling valve assembly for demountable engagement with a neck portion extending from a pressurizable fluid container. The coupling valve assembly comprises: (i) an outer twist-lock casing for receiving therein a valve housing, wherein the twist-lock casing and a lower portion of the valve housing define a channel for receiving therein the neck portion; (ii) an assembly forming a chamber for receiving and biasing therein a valve stem against a main seal interposed the valve housing and the assembly, (iii) a lower retainer having a plurality of engagement devices for engaging a lower portion of the valve housing, wherein the lower retainer houses a spring for biasing the assembly against the main seal. The outer twist-lock casing is provided with a plurality of lock slot orifices for receiving and engaging therein a plurality of locking ribs provided therefor on the neck portion of the pressurizable fluid container.

Description

TITLE: DEMOUNTABLE COUPLER VALVE FOR ONE-WAY KEGS

TECHNICAL FIELD

This disclosure relates to containers for storing and transporting fluids. More specifically, this disclosure pertains to valve components for demountable engagement with pressurized beverage containers.

BACKGROUND

Containers for receiving, storing, transporting, and dispensing carbonated beverages are designed to safely contain fluids at internal pressures which greatly exceed ambient external atmospheric pressures. It is common practice for beverage container designs to exploit the higher internal pressure to provide structural stiffening of the containers, whereby the internal pressure aids in the resistance to dents, buckling or collapse of the container during handling and transport. For manufacturing reasons, sharp corners may be inappropriate for a pressurized beverage container, as the internal pressure will tend to deform the container corners. Adding extra material to stiffen the corners to prevent excessive deformation under pressure may not be desirable due to manufacturing cost and container weight. Therefore, an ideal beverage container which is able to contain an internal pressure and is lightweight may be a largely curved container such as a sphere, or an elongate cylinder with domed ends.

Such beverage containers are exemplified by beer kegs manufactured from stainless steel or aluminum. Beer kegs have been standardized in most countries to contain 50 L of beer when full (equivalent to 13.2 US gal). However, US kegs may be sized to contain 15.5 US gal. (equivalent to 59 L). Beer kegs typically include a single opening on one end, commonly referred to as a "bung" and another opening at the other end of the keg from which, or into which, extends a tube or "spear". A self-closing valve is opened by a coupling fitting which is attached to the spear when the keg is tapped. The coupling fitting has one or two valves which control the flow of beer out of and gas into the keg. The keg must be kept upright, with the opening on top for the beer to be dispensed. Restaurants and bars often use a pressurized gas system to deliver a beverage from the keg to a dispensing tap. Common pressurization gases are food-grade carbon dioxide, nitrogen, or combinations thereof. The gas is delivered into the headspace at the top of the keg above the beverage. This pressure forces the beverage in turn through the spear, the valve, and the delivery line to the dispensing tap.

Fluids contained in a filled keg are accessed by demountably engaging a coupler device with the spear component of the keg. The upper end of the spear component typically comprises a ball valve and a reinforced rib extending axially outward around the periphery of the spear component. The reinforced rib may have different configurations selected for demountable engagement of a specific coupler device. For example, a D-style coupler, a S-style coupler, a U-style coupler, an A-style coupler, a G- style couple, a M-style coupler, and the like. Such couplers are designed to engage the upper end of the spear by a twisting-on motion so that the coupler engages the reinforced rib, and then to disengage the spear by a twisting-off motion. Most couplers for kegs additionally comprise a valve component, for example, as described in US Pat. No. 3,939,860.

Beer kegs formed from plastics materials exemplified by polyethylene terephthalate were recently developed to reduce their empty weight thereby reducing transportation costs and increasing ease-of-handling. Such kegs are commonly referred to as "one-way" kegs or "one-use" kegs and are discarded after use by a consumer such as a bar or a restaurant. One-way kegs enable a brewery to distribute their products over greater distances and areas. Existing, standard delivery modes can also be used for distribution of one-way kegs. One-way kegs are typically formed by injection molding and consequently are much less expensive than metal kegs. Other cost reductions for breweries include the doing away of the need for capital equipment and facilities to wash and sanitize used beer kegs.

Most one-way kegs formed from plastics also comprise spears that are concurrently molded from the plastics materials. It is often difficult to securely engage couplers designed for use with metal kegs, with one-way plastics kegs. The metal components of the couplers can gouge or score the outer and inner edges of the spear ends thereby resulting in leakage of the pressurized fluids during pumping. SUMMARY

The embodiments of the present disclosure relate to coupling valves for demountable engagement with the ends of spears extending out from one-way kegs or alternatively, one-use kegs. The coupling valves disclosed herein are useful for demountable sealingly engagement with one-way kegs and/or one-use kegs, whereby pressurized fluids contained within the kegs are easily recovered therefrom. The present coupling valves are sealingly engageable with a variety of tapping couplers, pumps and tubing for delivery of pressurizing gases for example C0₂, to facilitate recovery of fluids from the kegs. Additionally, the present coupling valves are also useful for depressurizing emptied kegs thereby facilitating safe decoupling and demounting of the coupling valves from emptied kegs.

The coupling valves disclosed herein comprise one or more pressure relief assemblies for releasing pressure from within the kegs. According to one aspect, a suitable pressure relief assembly comprises a burst disk such as those commercially available in a variety of sizes, shapes, and with various pressure values. Burst discs are typically pre-weakened by scoring, cutting, or via other standard methods, and rupture when the pressure in the container exceeds the maximum allowable working pressure. According to another aspect, the pressure relief assembly comprises a manually-operated pressure release means useful for venting any residual pressure remaining when all fluid has been recovered from a keg. For example, the manually-operated pressure release means may comprise a vent opening which is sealed by a tear-away tab. For example, the tear-away tab may be a color-coded, pressure-sensitive label which indicates, through a color change, when the pressure within the keg exceeds a maximum allowable working pressure. The tear-away tab can be readily removed by manually grasping the tab and tearing or removing the tab to uncover the vent opening, thereby allowing residual pressure to be released at a safe, controlled rate. For safety reasons, it may be preferable to require two manual steps to depressurize the container. For example, the first step may be the tearing away of a tab to uncover the vent, followed by a second step of depressing of a vent-opening button. Once removed, the tear-away tab cannot be reattached, thereby preventing the keg from re-pressurized and reused. BRIEF DESCRIPTION OF THE FIGURES:

The present disclosure will be described in conjunction with reference to the following drawings in which:

Fig. 1 is a perspective view of an assembled two-stage locking valve according to one embodiment of the present disclosure;

Fig. 2 is an exploded perspective side view of the two-stage locking valve shown in Fig. 1 ;

Fig. 3 is a perspective view of the twist-lock casing component of the two-stage locking valve shown in Fig. 2; Fig. 4 is an exploded perspective view of the valve housing and the couple seal components of the two-stage locking valve shown in Fig. 2;

Figs. 5(A), 5(B), 5(C) are exploded perspective views of the main seal (5(A)), the upper retainer (5(B)), and the mid retainer (5(C)) components of the two-stage locking valve shown in Fig. 2; Figs. 6(A), 6(B) are exploded perspective views of the valve stem component

(6(A)) and the inner valve spring (6(B)) of the two-stage locking valve shown in Fig. 2;

Figs. 7(A), 7(B) are exploded perspective views of the support body component (7(A)) and the outer valve spring (7(B)) of the two-stage locking valve shown in Fig. 2;

Fig. 8 is a perspective view of the lower retainer component of the two-stage locking valve shown in Fig. 2;

Fig. 9 is a partial cross-sectional perspective view of the two-stage locking valve shown in Fig. 2;

Fig. 10 is a cross-sectional side view of the two-stage locking valve shown in Figs. 2, 9; Fig. 11 is a perspective view of a collapsible one-way keg; Fig. 12(a) is a perspective view of the upper neck portion of the collapsible oneway keg shown in Fig. 11, while Fig. 12(B) is a perspective view of the two-stage locking valve demountably engaged with the upper neck portion of the keg and an standard coupler; Fig. 13 is a partial cross-sectional perspective view of the exemplary two-stage locking valve demountably engaged with the collapsible one-way keg shown in Fig. 11 ;

Fig. 14 is a partial cross-sectional perspective view of the exemplary two-stage locking valve demountably engaged with a bladder mounted within the collapsible oneway keg shown in Fig. 11 ; Fig. 15 is an exploded perspective view of a two-stage locking valve according to another embodiment of the present disclosure;

Fig. 16 is an exploded side view showing the twist-lock casing, the upper housing, the valve housing and the bottle seal components of the two-stage locking valve shown in Fig. 15; Fig. 17 is an exploded side view showing the main seal, the valve stem, and the inner valve spring components of the two-stage locking valve shown in Fig. 15;

Fig. 18 is an exploded side view showing the valve support body and the outer valve spring components of the two-stage locking valve shown in Fig. 15; and

Fig. 19 is an exploded side view showing the upper retainer, the mid retainer, the lower retainer, and the bladder coupler components of the two-stage locking valve shown in Fig. 15.

DETAILED DESCRIPTION

The embodiments of the present disclosure relate to valve components for demountable engagement with the end spears extending from elongate cylindrical one- way beverage containers or one-use beverage containers.

According to one embodiment, disclosed herein is a coupling valve for demountably engaging the spear extending outward from a one-way keg. One example of a coupling valve comprises a twist-lock casing wherein is housed a valve assembly defining an inner through channel and an outer through channel, wherein both channels have a valve resting in a closed position by way of a biasing spring. According to one aspect, the twist-lock casing is provided with at least two slots, wherein each slot is configured for receiving and releasably engaging therein a corresponding rib element extending axially outward from the rim of a spear integrally formed on the upper surface of a one-way keg.

One example of a coupling valve 10 according to the present disclosure is shown in Figs. 1-10, and generally comprises a twist-lock casing 15, a valve housing 20, a main seal 25 for sealably engaging the valve housing 20, a valve 40 abutting the main seal 25, an upper retainer 30 and mid retainer 35 for housing the valve 40, an inner biasing spring 41 for cooperating with a valve support body 45 to controllably bias the valve 40 into a resting closed position. The valve 40 comprises a valve stem 43 sxtending upward into a valve head 42 onto which is afixed a valve gasket 44. A coupler seal 21 is sealing interposed the valve housing 20 and the valve support body 45. The valve support body 45 extends through a lower retainer 50 which is engaged with a lower portion of the valve housing 20. The valve support body 45 is biased into a closed resting position against the main seal 25 by an outer valve spring 49 in cooperation with the lower retainer 50. Various components comprising coupling valve 15 may be formed from resilient plastics material and may be provided with slots, rims, openings and fingers with retainers at their distal tips to enable the components to be assembled by "snapping together", for example by engagement of a retainer on a finger tip extending upward from one component with a slot provided therefor on an upper component. For example, the inner surface of the twist-lock housing 15 may have a rim 15a with two or more slots 17 spaced around the circumference of the twist-lock housing 15 to engage and retain a rib 22 extending axially outward from the from the valve housing 20. The main seal 25 may have a foot 26 with a retainer at its distal end for engaging a foot retainer slot 31 integrally provided therefor on the upper retainer 30. The upper retainer 30 may have a foot 32 with a retainer at its distal end for engaging a foot retainer slot 36 integrally provided therefor on the mid retainer 35. The mid retainer 35 may have a foot 36 with a retainer at its distal end for engaging a foot retainer slot 46 integrally provided therefor on the valve support body 45. The valve support body 45 may have a downward extending foot 47 with a retainer at its distal end for engaging a foot retainer slot 51 integrally provided therefor on the lower retainer 50. The lower retainer 50 may have an upward extending foot 53 with a retainer at its distal end for engaging a foot retainer slot integrally provided therefor on the valve support body 45. The lower end of the lower retainer 50 may have a plurality of inward extending projections 52 for engaging a retaining channel 48 provided therefor near the lower end of the valve support body 45. The coupling valve 10 may be assembled by engaging, i.e., snap-fitting together the above-mentioned components as illustrated in Fig. 2. The present coupling valve 10 can be demountably engaged with a one-way keg by hand without the need for any additional tools. An example of a one-way keg 60 is shown in Fig. 11 and comprises a neck portion 62 communicating with the spear (not shown). The neck portion 62 generally comprises a neck having a pair of ribs 66 extending axially outward from the neck 64 (Fig. 12A). The twist-lock casing 15 component of the coupling valve 10 is provided with a pair of threaded lock slot 16 orifices configured for receiving therein and releasably engaging the ribs 66 on the neck portion 62 of the one-way keg 60. Fig. 12B shows a coupling valve 10 inserted into the neck portion of the one-way keg 60, wherein the coupling valve 10 is demountably engaged with a standard coupler 80. The neck 64 of the bottle 60 is inserted into the coupling valve 10 into the space between the twist-lock casing 15 and valve housing 20 until the pair of ribs 66 on the neck 64 engage the threads (not shown) provided on the inner surface of the twist-lock casing 15. The coupling valve 15 is then twisted in a clockwise direction to rotate about the pair of locking ribs 66 in the threads toward the lock slot 16 orifices; this step is referred to herein as the "first stage" of demountable engagement. The threads provided on the inner surface of the twist-lock casing spiral downward to produce a friction seal between the coupling valve 10 and the neck portion 62 of the bottle 60. The threads terminate at the lock slot 16 orifices. The twisting force on the coupling valve 10 is maintained until the lock slot 16 orifices pass over the pair of locking ribs 66 which then snap into and are mountedly engaged in the lock slot 16 orifices. This step is referred to herein as the "second stage" of demountable engagement. It is to be noted that when the coupling valve 10 is engaged with the neck portion 62 of the keg 60 in the second stage locked position, the threads channels disposed in the inner surface of the twist-lock casing 15 are not aligned with the locking ribs 66 on the neck 64 of the keg 60. Specifically, the coupling valve 10 is axially displaced away from the keg 60 thereby preventing rotation of the coupling valve 10 about the neck portion 62 and therefore, prevents inadvertent unscrewing and disconnection of the coupling valve 10 from the keg 60. This is useful, when filled one-way kegs are placed into a restaurant or bar for dispensing fluids contained therein, a standard coupling device 80 (Fig. 12B) will be demountably engaged with the top end of the coupling valve 10 for dispensing of the fluids. Typically, mounting and demounting of a standard coupling device to keg valves exemplified by the coupling valves disclosed herein, is generally done by engaging a thread on the keg valve and then rotating the standard coupling device about the keg valve until the two components are sealingly engaged. It is to be noted that engagement of the locking ribs on the neck portion of the keg with the lock slots provided on the twist-lock housing of the present coupling valve will not allow rotation or disconnection of the coupling valve from the keg as a result of the rotational forces exerted on the coupling valve during the mounting and demounting of a standard coupling device. When the keg is pressurized, the internal pressure biases the coupling valve into the second stage seating position and the force necessary to press down on the valve and align the valve thread slot with the locking blocks on the bottle neck is larger than typical forces exerted on the coupling valve during handling. This safety feature provides significant resistance to removal of the valve to prevent accidental removal when the keg is full or pressurized which would otherwise cause a dangerous release of pressure and/or a spill of the keg contents. It is within the scope of the present disclosure for the coupling valves disclosed herein to be demountably engaged with empty one-way kegs or one-use kegs before the kegs are filled with a fluid. According to one embodiment, this disclosure also relates to a one-way keg system or a one-use keg system comprising a disposable keg that has been provided with a coupling valve disclosed herein, sealably engaged with the keg. Such keg systems are deliverable to a brewery, for example a microbrewery, a craft brewery, and the like, for filling thereby simplifying the operations logistics for the brewery. A suitable one-way keg 70 fitted with an upper end cap 74 and a lower end cap 76 is shown in Fig. 13 with a coupling valve demountably engaged with the neck portion 72 of the one-way keg 70. It is also within the scope of the present disclosure for a bladder 85 to be sealingly mounted onto the lower portion of the valve support body 45 of an exemplary coupling valve 10 as shown in Fig. 14, after which, the bladder 85 may be inserted through the neck portion 84 of a one-way keg 82, after which, the coupling valve 10 is demountably and sealingly engaged with the neck portion 84. The bladder 85 may be attached to the lower portion of the valve housing 45 of the coupling valve 10 by, for example, one of ultrasonic welding or with a bonding agent or with by physical crimping or by combinations thereof. It is to be noted that the upper end caps 74, 76 extend upward from the one-way kegs sufficiently so that the upper peripheries of the end caps extend beyond the upper surfaces of the coupling valves thereby providing physical protection to the exemplary coupling valves demountably engaged with oneway kegs before they are handled or filled or shipped or dispensed from.

Another example of a coupling valve 100 according to the present disclosure is shown in Figs. 15-19, and generally comprises a twist-lock casing 105, a valve housing 115, a main seal 120 for sealably engaging the valve housing 115, a valve 130 abutting the main seal 125, an upper retainer 150 and mid retainer 155 for housing the valve 130, an inner biasing spring 135 for cooperating with a valve support body 140 to controllably bias the valve 130 into a resting closed position. The valve 130 comprises a valve stem 133 extending upward into a valve head 132 onto which is afixed a valve gasket 134. A coupler seal 120 is sealing interposed the valve housing 115 and the valve support body 140. The valve support body 140 extends through a lower retainer 160 which is engaged with a lower portion of the valve housing 20. The valve support body 140 is biased into a closed resting position against the main seal 125 by an outer valve spring 145 in cooperation with the lower retainer 160. Various components comprising coupling valve 100 may be formed from resilient plastics material and may be provided with slots, rims, openings and fingers with retainers at their distal tips to enable the components to be assembled by "snapping together", for example by engagement of a retainer on a finger tip extending upward from one component with a slot provided therefor on an upper component. For example, the inner surface of the twist-lock housing 105 may have a rim 106 with two or more slots 107 spaced around the circumference of the twist-lock housing 105 to engage and retain a rib 112 extending axially outward from the from the valve housing 115. The main seal 125 may have a foot 126 with a retainer at its distal end for engaging a foot retainer slot (not shown) integrally provided therefor on the upper retainer 150. The upper retainer 150 may have a foot 152 with a retainer at its distal end for engaging a foot retainer slot (not shown) integrally provided therefor on the mid retainer 155. The mid retainer 155 may have a foot 156 with a retainer at its distal end for engaging a foot retainer slot (not shown) integrally provided therefor on the valve support body 140. The valve support body 140 may have a downward extending foot 142 with a retainer at its distal end for engaging a foot retainer slot (not shown) integrally provided therefor on the lower retainer 160. The lower retainer 160 may have an upward extending foot 163 with a retainer at its distal end for engaging a foot retainer slot integrally provided therefor on the valve support body 140. The lower end of the lower retainer 160 may have a plurality of inward extending projections 162 for engaging a retaining channel 143 provided therefor near the lower end of the valve support body 140.

It is to be noted that the coupling valves disclosed herein greatly simplify the depressurization of one-way kegs that have been emptied of their fluid contents. For example, a downward pressure may be applied to the top of a coupling valve while turning it counter-clockwise causes the locking ribs 66 to disengage from the lock slots 16 and to enter the threads channels disposed in the inner surface of the twist-lock casing 15. As a result, the pressure within the keg is released from the neck opening as the coupling valve is further rotated counter-clockwise within the threaded channels to their termination points until the coupling valve enters a flat horizontal area disposed between within the threaded channels, i.e., the first stage seating position. This area is placed at a specific point whereby the valve becomes unsealed from the bottle and vents the pressure contained within the vessel outward around the circumference of the neck opening. This flat horizontal area disposed between within the threaded channels also prevents the coupling valve from pressurized ejection from the keg. Once the internal pressure has been released from within the keg, continued counter-clockwise rotation of the coupling valve will bring the locking ribs to the surface entrance of the threaded channels adfter which, the coupling valve can be safely separated from the keg for disposal. It should be noted that the extent of downward force required to release the valve from the secondary stage locking cavity and depressurization is the combination of internal keg pressure (60- 90 psig), the compression rating, and thickness of the seal. Both the downward force on the valve and the counter clockwise turning motion prevent the accident depressurization and removal of the valve from the bottle. Optionally, the bottle or the valve include secondary pressure release mechanisms such as burst disks which prevent over-pressure damage of the keg, or tear-away tabs or puncture points which allow the keg to be vented. Optionally, the removed valve can be further disassembled or broken apart to separate the different valve components for recycling of the component materials.

It is within the scope of the present disclosure for the coupling valves to be compatible with standard couplers used in the industry, for example the D-Valve coupler. The exemplary coupling valves may comprise polymer components and stainless steel components. For example, the twist-lock casing, valve housing, valve stem, upper retainer, mid retainer, lower retainer, valve support body can be injection molded with a plastics material exemplified by polyethylene, polypropylene, and the like. The inner valve springs and outer valve springs may comprise stainless steel. The seals may comprise a resiliently compressible material for example a fluorocarbon such as VITON^® (VITON is a registered trademark of Lautsprecher Teufel GmbH Corp., Berlin, Fed. Rep. Ger.), FLUOREL^® (FLOUREL is a registered trademark of Minnesota Mining & Manufacturing Co., St. Paul. MN, USA), and the like.

Claims

1. A two-stage coupling valve assembly for demountable engagement with a neck portion extending from a pressurizable fluid container, the coupling valve assembly comprising:

an outer twist-lock casing having an an inward-extending annular rim at an upper end of the casing;

a valve housing rotationally and sealingly engageable within the twist-lock casing; a valve chamber assembly housed within the valve housing;

a main seal for sealing engagment of the valve housing with the valve chamber;

a valve assembly housed within the valve chamber assembly;

a lower retainer demountably engageable with the valve housing; and

a bladder mount.

2. The two-stage coupling valve assembly of claim 1, wherein the outer twist-lock casing has two sets of opposing orifices, wherein a first set of orifices is positioned above a second set of orifices, and said second set of orifices configured for demountable engagement with a plurality of locking ribs provided therefor on a neck portion of the valve housing.

3. The two-stage coupling valve assembly of claim 1, wherein the valve housing has an upper portion and a lower portion with the upper portion having a wider diameter than the lower portion, said upper portion of the valve housing sealingly engageable with the inward- extending annular rim at the upper end of the twist-lock casing, said valve housing having (i) an inward-extending annular rim at about the juncture of the upper portion and the lower portion, and (ii) an outward-extending seal seat about the lower portion of the valve housing for receiving there in coupler seal, and wherein the outer twist-lock casing and the lower portion of the valve housing define a channel for receiving therein the neck portion of the pressurizable fluid container, said lower portion of the valve housing having a plurality of orifices therearound for demountable receiving engagement devices.

4. The two-stage coupling valve assembly of any of claims 1 to 3, wherein the valve chamber assembly comprises an upper retainer, a mid retainer and a valve support body having an inward-extending annular rim disposed in a lower portion of said valve support body, wherein the upper retainer abuts the main seal.

5. The two-stage coupling valve assembly of any of claims 1 to 4, wherein the valve chamber assembly has an inner valve spring disposed between valve stem and the inward- extending annular rim disposed in a lower portion of said valve support body thereby biasing the valve stem against the main seal.

6. The two-stage coupling valve assembly of any of claims 1 to 5, additionally comprising a pressure relief assembly.

7. The two-stage coupling valve assembly of claim 6, wherein the pressure relief assembly comprises a burst disc.

8. The two-stage coupling valve assembly of claim 6, wherein the pressure relief assembly comprises a manually operated pressure relief means.

9. The two-stage coupling valve assembly of claim 8, wherein the manually operated pressure relief means is a tear-away tab.

10. A two-stage coupling valve assembly for demountable engagement with a neck portion extending from a pressurizable fluid container, the coupling valve assembly comprising:

an outer twist-lock casing having an inward-extending annular rim at the upper end of the casing, and having two sets of opposing orifices, wherein a first set of orifices is positioned above a second set of orifices, and said second set of orifices are configured for demountable engagement with a plurality of locking ribs provided therefor on the neck portion, said second set of orifices communicating with a spiral thread extending downward; a valve housing having an upper portion and a lower portion with the upper portion having a wider diameter than the lower portion, said upper portion of the valve housing sealingly engageable with the inward-extending annular rim at the upper end of the twist-lock casing, said valve housing having (i) an inward-extending annular rim at about the juncture of the upper portion and the lower portion, and (ii) an outward-extending seal seat about the lower portion of the valve housing for receiving there in coupler seal, and wherein the outer twist-lock casing and the lower portion of the valve housing define a channel for receiving therein the neck portion of the pressurizable fluid container, said lower portion of the valve housing having a plurality of orifices therearound for demountable receiving engagement devices;

a main seal having a top surface abutting the inward-extending annular rim in the valve housing;

an assembly forming a chamber for receiving therein a valve stem, said assembly comprising an upper retainer, a mid retainer and a valve support body having an inward- extending annular rim disposed in a lower portion of said valve support body, wherein the upper retainer abuts the main seal, said assembly having an inner valve spring disposed between valve stem and the inward-extending annular rim disposed in a lower portion of said valve support body thereby biasing the valve stem against the main seal; and

a lower retainer having an inward-extending annular rim at the lower end of the retainer, and having a plurality of engagement devices for demountably engaging the plurality of orifices provided the lower portion of the valve housing, said lower retainer having an outer valve spring for receiving therethrough the valve support body thereby biasing the assembly against the main seal.