AU2004201182B2 - An improved valve - Google Patents

Description

AN IMPROVED VALVE This invention relates to an improved valve. This invention has particular but not exclusive application to an improved valve for domestic use as a tap or faucet for water, and for illustrative purpose reference will be made to such application. However, it is to be understood that this invention could OO be used in other applications such as valves for commercial or industrial use in chemical plant or such like.

(The use of valves is widespread in the distribution of municipal water supplies. Taps or faucets for domestic use may be of a rotary design which includes a valve body, a closure element such as a tap washer assembly and means for positioning the closure element to seal against a seat in the tap body, such as a valve stem or spindle assembly. The valve body withstands the internal pressure of the fluid to be controlled by the valve, provides a flow path for fluid to pass through the valve, and supports the other valve elements. The closure element is movable from an open attitude allowing fluid flow through the valve to a closed attitude where fluid flow is not permitted through the valve. Valve maintenance requires occasional reseating. The reseating operation requires the valve to be isolated from the fluid supply and the bonnet and valve stem removed. The seat is then usually machined or ground until substantially flat, and then the valve stem and bonnet are replaced.

In some situations, the location of the valve body makes it difficult to perform the reseating operation. Additionally, reseating limits the life of the valve, and replacement of the valve is costly and time consuming. Moreover, should the reseating operation damage the valve body, then the valve body has to be removed from the connecting plumbing and replaced. In domestic situations, to replace the valve body, the surrounding decor quite often needs restoration, adding to the cost of replacement.

Valves having a separate seat ring have been provided in some industrial applications. The seat ring in such valves is usually located in a recess formed in the tap body and is retained between the valve body and the bonnet. This arrangement is prone to leakage around the seat ring.

This invention aims to alleviate one or more of the above 0 disadvantages and to provide an improved valve assembly which will be reliable and efficient in use.

With the foregoing in view, this invention in one aspect resides broadly in a valve including: 00 a valve body; a bonnet assembly mounted in said body and having a removable seat (element at an inlet thereto and an outlet, said inlet and outlet forming a flow passage through said valve body; and a spindle assembly mounted in said bonnet assembly and adapted to selectively advance a closure to sealably engage said seat and close said passage.

In one embodiment, the movable closure element may include a spindle assembly and the positioning means may include a bonnet assembly which is threadably engaged with the spindle assembly. Furthermore, the removable seat element may be retained in the bonnet assembly. For example the removable seat element may be threadedly engageable with the bonnet assembly.

The removable seat element may also include an extension portion into which an internal thread is provided for the threaded engagement of the removable seat element therein. Suitably, the extension portion includes a fluid flow path therethrough since the extension portion is operatively interposable between the fluid inlet and the fluid outlet.

The bonnet assembly may include an axial bore defining the inlet. The removable seat element may comprise an annular seat or seat ring engaged with the bore. For example, the seat ring may be supported in the bonnet assembly by threaded engagement therewith, to define the beginning of a fluid flow path therethrough.

Preferably, the valve body includes a standard design domestic tap valve body having a valve seat and the positioning means and movable closure element include a bonnet assembly, a spindle assembly, washer assembly and washer. In order to accommodate the fluid path through the valve bonnet, it is preferred that the bonnet assembly be in the form of a a conventional bonnet with a bonnet extension portion being provided and the C removable seat ring being engaged with the bonnet extension. Suitably, the bonnet extension includes apertures whereby the outlet includes a passage extending through the wall of the bonnet to a space formed between the bonnet and the tap body.

_The bonnet extension may be integrally formed with, or fixedly attachable to, the bonnet. The apertures provide part of the flow path through the bonnet assembly.

Preferably, the sealing engagement of the bonnet assembly with the valve body for sealing fluid flow between the inlet and the outlet is achieved with the removable seat ring having a surface adapted to engage the corresponding conventional seat surface provided in the tap body.. The spindle assembly is preferably sealingly engaged in the bonnet assembly in the normal manner.

Accordingly, the spindle assembly may be sealed against leakage by an annular seal between the bore and the spindle.

It is also preferred that the spindle assembly includes washer locating means for locating a washer in the spindle for sealable engagement with the seat ring.

The engagement of the removable seat and bore may be a threaded engagement. The seat may be provided with key engagement means to facilitate installation and removal of the seat from the bore by use of a key.

When the valve is in the closed position, the bonnet assembly is positioned in the valve body so that the seat ring sealingly engages with the valve body and the spindle is positioned in the bonnet assembly so that the washer is in sealing engagement with the seat ring. In the open position, the spindle is moved so that the washer is not in sealing engagement with the seat ring. The seat ring remains in sealing engagement with the valve body, but fluid is permitted to flow through the flow path provided in the bonnet assembly.

Since the washer engages and disengages with the seat ring to close and open the valve, there is little if any wear on the seat in the valve body.

For reseating the valve, the seat ring is the only part that needs replacement, reducing the downtime for valve maintenance.

_In order that this invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawing which illustrates a preferred embodiment of the invention and wherein 00 Fig. 1 is an exploded, part section, side view of a valve assembly.

Referring to Fig. 1, a valve assembly 10 includes a bonnet assembly in

O

the form of bonnet 11, a spindle 12, a washer assembly 13, a removable seat Selement in the form of seat ring 14, and a locking nut 15 and a valve body 16.

S 10 The bonnet assembly 11 includes a threaded portion 21, an extension portion 22, and an upper portion 24. The extension portion 22 includes six flow path apertures shown typically at 23 (four of which are visible). The upper portion 24 includes two flats 25 on the outside and a spindle aperture 26 in the end. Respective spindle engagement threads 27 are provided about the internal surface of the upper portion 24.

The threaded portion 21 has an inner bearing surface 29 of substantially constant cross-section and relatively smooth finish. The extension portion includes seat ring engagement threads 28 extending about the internal surface.

The spindle 12 includes an o-ring 31 engaged in an o-ring channel 36.

Respective bonnet engagement threads 32 engage with the spindle engagement threads 27 on the bonnet 11 for axial movement of the spindle 12 with respect to the bonnet 11 thereby providing a positioning means.

A handle attachment portion 33 includes respective handle attachment threads 34 for attaching a handle (not shown) and further includes two spindle flats 37. A washer aperture 35 is also provided axially into the bore of the spindle 12 as shown. The washer assembly 13 includes a washer support 41 and a washer spindle 42 extending axially therefrom. A washer 43 is supported on the washer support 41 and fixed thereto by a washer fastener 44. The washer assembly and washer act with spindle 12 as a movable closure element. Seat ring 14 includes respective circumferential threads 51 which engage with the seat ring engagement threads 28 on the bonnet 11.

The seat ring 14 also includes an inner passage 53, an upper bearing surface 54, and a lower bearing surface 55. The seat ring 14 also includes two lug e( d apertures 52 (one of which is visible) by which a lug spanner (not shown) may be used to turn the seat ring 14 about its axis. Thus, the seat ring may be turned into and out of the seat ring engagement threads 28 in the bonnet 11 for installation and removal respectively. Additionally, the seat ring position oO may be adjusted. It will be appreciated that the seat ring is suitably positioned to leave at least some of it protruding a distance sufficient to permit sealing Sengagement with the seat.

The valve body 16 includes an inlet portion 62 having an inlet 65 and an outlet portion 61 having an outlet 64 through which fluid may flow in the direction of an arrow 66. The outlet portion 61 includes an internal threaded portion 63 for receiving the bonnet 11 by engagement of the threaded portion 21. A seat surface 67 is provided between the inlet 65 and the outlet 64 against which the seat ring 14 is operatively sealingly engaged.

The locking nut 15 includes locking threads 49 about the inner surface of the ring and a body engaging surface 48.

When assembled, the spindle 12 is engaged with the bonnet 11 by way of the bonnet engaging thread 32 being threadedly engaged with the spindle engagement threads 27. The handle attachment portion 33 extends upwardly through the spindle aperture 26 and may then receive a handle (not shown) which is generally held in place by engagement of a nut onto the handle attachment threads 34.

The o-ring 31 bears sealingly against the inner bearing surface 29 to prevent fluid from leaking through the spindle aperture 26.

The washer assembly 13 is inserted by its washer spindle 42 into the washer aperture 35 in the spindle 12. The spindle 12 is inserted into the bonnet 11 a distance sufficient for the washer 43 to be axially inward from the end of the extension portion a distance sufficient to permit the seat ring 14 to be engaged into the extension portion 22 by threaded engagement of the circumferential threads 51 with the seat ring engagement threads 28.

Once the seat ring 14 is in place, the threaded portion 21 of the bonnet 11 may be engaged with the internal threaded portion 63 on the valve body 16, the bonnet 11 being turned so that the lower bearing surface 55 sealingly engages with the seat surface 67. A sealing means for example in the form of 0 a sealing washer may be interposed between the lower bearing surface and the seat surface 67 if desired. The locking nut 15 is then threadedly engaged with the threaded portion 21 and turned down until the body engaging surface 48 engages with the nut bearing surface 68 on the valve OO body 16. The locking nut 15 thus locks the bonnet 11 onto the valve body 16.

_Once the bonnet 11 has been sealed in place with the locking nut (the spindle 12 may be turned to either close or open the valve assembly The valve assembly 10 is closed when the valve 43 sealingly engages with the upper bearing surface 54 of the seat ring 14, and is progressively opened when the spindle 12 is wound about its axis so that the washer assembly 13 is moved axially away from the upper bearing surface 54 of the seat ring 14.

Suitably, the total cross-sectional surface area of the flow path apertures 23 is not substantially less and the flow path area of the outlet 64 or the inlet 66 in order to minimise flow restriction through the valve assembly when assembled and in the fully opened position.

In use, the valve assembly of the present invention may be installed in new plumbing fixtures. Where a valve body 16 is already provided, the bonnet 11, spindle 12, washer assembly 13, seat ring 14 and locking nut may be provided separately to provide the valve assembly of the present invention.

The locking nut 15 may also be provided with a washer interposed between its body engaging surface 48 and the nut bearing surface 68.

It will of course be realised that while the above has been given by way of illustrative example of this invention, all such and other modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as herein set.

Claims (12)

1. A valve including: a valve body; a bonnet assembly mounted in said body and having a removable seat OO element at an inlet thereto and an outlet, said inlet and outlet forming a flow passage through said valve body; and a spindle assembly mounted in said bonnet assembly and adapted to selectively advance a closure to sealably engage said seat and close said passage.

2. A valve according to claim 1, wherein the bonnet assembly includes an axial bore defining said inlet.

3. A valve according to claim 2, wherein said removable seat element comprises an annular seat engaged with said bore.

4. A valve according to claim 3, wherein the engagement of the seat and bore is a threaded engagement.

A valve according to claim 4, wherein said seat is provided with key engagement means to facilitate installation and removal of the seat from the bore by use of a key.

6. A valve according to any one of the preceding claims, wherein said seat element has a surface adapted to engage a corresponding seat surface provided in said tap body.

7. A valve according to any one of the preceding claims, wherein the bonnet assembly is threadably engaged with said valve body.

8. A valve according to any one of the preceding claims, wherein said closure is a tap washer assembly.

S9. A valve according to any one of the preceding claims, wherein the spindle assembly is threadably engaged with the bonnet assembly for advancement of said closure. 00oO

10. A valve according to any one of claims 2 to 9, wherein said spindle assembly is sealed against leakage by an annular seal between said bore and Ssaid spindle.

11. A valve according to any one of the preceding claims, wherein said outlet includes a passage extending through the wall of the bonnet to a space formed between the bonnet and the tap body.

12. A valve assembly as described herein with reference to Figure 1. DATED THIS ELEVENTH DAY OF SEPTEMBER 2006 LAWRENCE SMITH BY PIZZEYS PATENT AND TRADE MARK ATTORNEYS