AU733947B2

AU733947B2 - A valve arrangement

Info

Publication number: AU733947B2
Application number: AU87939/98A
Authority: AU
Inventors: Douglas Harold Emmins
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-08-26
Filing date: 1998-08-26
Publication date: 2001-05-31
Anticipated expiration: 2018-08-26
Also published as: AU8793998A

Description

PCT/AU98/00684 Received 25 May 1999 1 A VALVE ARRANGEMENT FIELD OF INVENTION This invention relates to valves for controlling the flow of fluids and more particularly to improving flow through such valves.

BACKGROUND AND PRIOR ART A valve is used in a fluid flow line to stop flow in that line. This generally requires some form of obstruction in the fluid flow line to stop flow. When flow is required it is desirable to move the flow restricting obstruction as much out of 1 0 a valve chamber as possible so that it and the valve chamber give as little flow obstruction as possible. It is inevitable, however, that in a valve a certain loss in pressure or head loss across the valve occurs owing to the constructional features of the valve.

A significant loss occurs due to turbulence forming in a valve chamber and this 1 5 turbulence can be carried downstream of the valve chamber into a valve outlet flow path.

It is an object of this invention to provide an improvement in flow through a valve or a reduction in pressure head loss across such a valve.

The invention will be discussed generally in relation to a diaphragm valve but 2 0 the principle therein may be applicable to a wide range of valves.

BRIEF DESCRIPTION OF INVENTION In one form therefore the invention is said to reside in a valve of a type having a valve chamber, an inlet, an outlet, an inlet flow path, an outlet flow path and a valve member adapted to enter the valve chamber to prevent flow through the 2 5 valve, the valve being characterised by at least two flow directors in the outlet flow path whereby to improve the flow through the valve and to reduce head loss across the valve.

In an alternative form the invention is said to reside in a diaphragm valve of a type having a valve chamber, an inlet, an outlet, an inlet flow path and an AMENDED SHEET (Article 34) (IPEA/AU) PCT/AU98/00684 Received 25 May 1999 2 outlet flow path and a diaphragm arrangement including a diaphragm adapted to enter the valve chamber to prevent flow through the diaphragm valve, the diaphragm valve being characterised by at least two flow directors in the outlet flow path whereby to improve flow through the valve and to reduce head loss across the valve and the flow directors are angled to the direction of flow of the '-iuid in the valve so that the cross sectional area between adjacent flow directors reduces towards the outlet from the valve chamber.

In a preferred embodiment of either of these forms of the invention there may be two to five flow directors in the outlet flow path.

1 0 Preferably, the flow directors comprise plates extending along the flow path.

The angle between a longitudinal line through the valve and the direction of longitudinal extent of the or each flow director on each side of a notional centre line of the valve or from an adjacent flow director may be in the range of from to 200.

1 5 Where there are two flow directors the angle between a notional centre line of the valve and the flow director on each side of it may be about 100.

Where there are three flow directors the angle between a centre flow director and the flow director on each side of it may be about 100.

Where there are four flow directors the angle between a notional centre line of the valve and the first flow director on each side of it may be about 100 and the angle between the first flow director on each side and the second flow director on each side of it may be about 100.

Where there are five flow directors the angle between a centre flow director and the first flow director on each side of it may be about 100 and the angle between the first flow director on each side and the second flow director on each side of it may be about 100.

Preferably the diaphragm valve body and the flow directors are made as a single casting or moulding from plastics material, brass or cast iron.

AMENDED SHEET (Article 34) (IPEA/AU) 1. 1 PCT/AU98/00684 Received 25 May 1999 3 The valve may further include at least one flow director on the inlet flow path.

Generally the valve chamber region of a valve is of a larger volume than the flow path into and out of a valve and the directors assist in returning flow from the valve chamber into the outlet flow path.

In the case of a diaphragm valve it is known to place single diaphragm support arrangements into one or both of the inlet flow path and outlet flow path with the primary aim of providing support for the diaphragm when it is in the closed position to prevent buckling of the diaphragm with potential leaking and damage problems. These single plates can assist with flow direction but it has 1 0 been found that the addition of one or more further flow directors in the outlet of the valve particularly if they provide a slightly tapered flow path towards the outlet of the valve do substantially reduce pressure head loss across the valve.

Although the mechanism involved which actually assists in reducing the head loss or improving the flow through the valve with the flow directors of the 1 5 present invention is not fully understood it is believed that the improvement may be a result of three factors. The applicant does not wish to be held to these explanations but they may assist in understanding of the nature of the improvement.

A first factor may be that the flow directors act to straighten out the turbulence merely by being placed in the outlet flow from the valve.

A second explanation may be that the flow directors in tapering the flow path to the outlet may provide a venturi effect which actually increases the flow rate at the outlet thereby drawing fluid out of the valve to improve the flow.

A third factor may be that the plates prevent or reduce cavitation in the fluid as it 2 5 flows over the valve seat associated with the valve arrangement and thereby reduces friction and hence allows less head loss across the valve.

The number of flow directors used in the valve may be to some extent dependent upon the size of the valve. For instance, in a 50mm diaphragm valve there may be two flow directors which are angled towards each other 3 0 towards the outlet of the valve.

AMENDED SHEET (Article 34) (IPEA/AU) PCT/AU98/00684 Received 25 May 1999 4 In a larger valve such as an 80mm or 150mm diaphragm valve there may be three or five flow directors in the outlet.

Preferably the flow director plates extend back into the valve to the extent that they provide a support surface for the diaphragm on the downstream side of the valve.

BRIEF DESCRIPTION OF THE DRAWINGS This then generally describes the invention but to assist in understanding reference will now be made to the accompanying drawings which show a preferred embodiment of the invention.

1 0 FIG 1 shows one embodiment of a diaphragm valve according to the invention in side view; FIG 2 shows a cross-sectional view of the valve shown in FIG 1 with the valve closed; FIG 3 shows a cross-sectional view of the valve shown in FIG 1 with the valve open; FIG 4 shows a plan view of the body of a diaphragm valve according to one embodiment of the invention; FIG 5 shows an end view from the outlet end of the body of a diaphragm valve according to the embodiment of the invention shown in Fig 4; FIG 6 shows a perspective view from the inlet end of the embodiment of the invention shown in Fig 4; FIG 7 shows a perspective view from the outlet end of the embodiment of the invention shown in Fig 4; FIG 8 shows a plan view of the body of a diaphragm valve according to an alternative embodiment of the invention; FIG 9 shows a plan view of the body of a diaphragm valve according to AMENDED SHEET (Article 34) (IPEA/AU) PCT/AU98/00684 Received 25 May 1999 another embodiment of the invention; and FIG 10 shows a plan view of the body of a diaphragm valve according to another embodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS Now looking more closely at the drawings and in particular FIGS 1 to 7, it can be seen that the valve of this embodiment comprises a valve body 1 with an inlet end 2 and outlet end 3. The valve body 1 has a planar upper surface 5 as best can be seen in FIGS 6 and 7 onto which is fitted a valve cap 6 with a diaphragm 8 sandwiched between the valve cap 6 and the valve body 1. Bolts 1 0 9 hold the valve cap to the valve body and act to retain the diaphragm around its periphery.

In the flow prevention state as can be seen in FIG 2 spring 10 holds the diaphragm 8 so that its central portion 11 rests onto valve seat 12. The valve is held closed by water pressure through pipe 13 which takes a fluid pressure 1 5 tapping from the inlet end 2 as can be seen in FIG 1 when valve 15 in the tube 13 is opened.

When valve 15 is closed liquid pressure in the diaphragm chamber 16 is allowed to bleed out to waste (by means not shown) and liquid pressure in the valve inlet flow path 2 against the diaphragm 8 causes the diaphragm 8 to lift up against the spring 10 so that flow can occur through the valve as shown by arrow 17 in FIG 3.

A diaphragm support plate 20 is provided in the inlet flow path and a combination flow director and diaphragm support plate 21 is provided in the outlet flow path.

2 5 Also provided in the outlet flow path 3 are two further flow director plates 22 and 23 as can be seen in FIGS 4 to 7. These additional flow director plates 22 and 23 have a curved leading edge which is substantially the shape of the diaphragm when it is in its closed position so they will also assist with support of the diaphragm when it is in the closed position. The plates 23 and 22 are 3 0 angled to the general direction of flow through the valve so that the cross sectional area of the flow path between them and the sides AMENDED SHEET (Article 34) (IPEA/AU) PCT/AU98/00684 Received 25 May 1999 6 of the valve chamber reduces in the direction of flow. This can be particularly seen in FIGS 4 and As can be seen in FIG 4 the angle a between the notional centre line of the valve shown by dotted line 25 and the direction of longitudinal extent of the flow director 23 as shown by dotted line 26 can be in the range of from 80 to 200 and is preferably about 100.

FIG 8 shows an alternative embodiment of a diaphragm valve body according to the invention. In this embodiment the valve body 40 has a flange connection 41 at the inlet end 42 and. a flange connection 43 at the inlet end 44..-In the 1 0 valve chamber 46 there is a valve seat 48 upon which the diaphragm (not shown) engages to prevent flow through the valve. On the inlet side of the valve seat 48 there is a single flange 50 which provides support for the diaphragm when it is in the closed position. On the outlet side of the valve seat 48 there are a set of five flow director flanges 51, 52, 53, 54 and 55 which act to 1 5 smooth flow through the valve when the valve is opened. The central flange 53 is substantially parallel to the direction of flow through the valve and the flanges 51, 52, 54 and 55 are angled to the central flange 53 so that the space between them reduces in cross sectional area towards the outlet 44. A diaphragm valve with five flow directors in the outlet flow path is particularly useful for valves adapted to be connected to pipes with diameters of 150mm or above.

FIG 9 shows another embodiment of a diaphragm valve body according to the invention. In this embodiment the valve body 60 has a screw threaded connection 61 at the inlet end 62 and a screw threaded connection 63 at the inlet end 64. In the valve chamber 66 there is a valve seat 68 upon which the diaphragm (not shown) engages to prevent flow through the valve. On the outlet side of the valve seat 48 there are a set of two flow director flanges 71, and 72 which act to smooth flow through the valve when the valve is opened.

There is no central flange but the flanges 71 and 72 are angled to each other 3 0 so that the space between them reduces in cross sectional area towards the outlet 64. A diaphragm valve with only two flow directors in the outlet flow path is particularly useful for valves adapted to be connected to pipes with diameters of 50mm or less. Such a valve body may be manufactured from plastics material by processes such as injection moulding.

AMENDED SHEET (Article 34) (IPEA/AU) PCT/AU98/00684 Received 25 May 1999 7 As can be seen in FIG 9 the angle P between the notional centre line of the valve shown by dotted line 73 and the direction of longitudinal extent of the flow director 71 as shown by dotted line 74 can be in the range of from 80 to 200 and is preferably about 100.

FIG 10 shows another embodiment of a diaphragm valve body according to the invention. In this embodiment the valve body 80 has a drop in type connection 81 at the inlet end 82 and the other part of the drop in connection 83 at the inlet end 84. In the valve chamber 86 there is a valve seat 88 upon which the diaphragm (not shown) engages to prevent flow through the valve. On the inlet 1 0 side of the valve seat 88 there is a single flange 90 which provides support for the diaphragm when it is in the closed position. On the outlet side of the valve seat 88 there are a set of four flow director flanges 91, 92, 93 and 94 which act to smooth flow through the valve when the valve is opened. There is no central flange but the flanges 91 and 92 on one side of the centre line are angled to 1 5 each other and the flanges 93 and 94 on the other side of the centre line are angled to each other so that the space between them reduces in cross sectional area towards the outlet 84. A diaphragm valve with four flow directors in the outlet flow path may be particularly useful for valves adapted to be connected to pipes with diameters of 100mm to 150mm.

The diaphragm valve body according to this invention including the flow directors may be made as a single casting or moulding from plastics material, brass or cast iron or may be fabricated by known methods.

Preferably the flow directors are moulded or cast into the valve bodies at the time of formation.

Throughout this specification various indications have been given to the scope of this invention but the invention is not limited to any one of these but may reside in one or more of these combined together. The examples and preferred embodiments are given for illustration only and not for limitation.

Throughout this specification and the claims that follow unless the context 3 0 requires otherwise the terms 'comprise' and 'include' and variations such as 'comprising' and 'including' will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

AMENDED SHEET (Article 34) (IPEA/AU)

Claims

1. A valve of a type having a valve chamber, an inlet, an outlet, an inlet flow path, an outlet flow path and a valve member adapted to enter the valve chamber to prevent flow through the valve, the valve being characterised by at least two flow directors in the outlet flow path whereby to improve the flow through the valve and to reduce head loss across the valve, wherein the flow directors are angled to the direction of flow of the fluid in the valve so that the cross sectional area between adjacent flow directors reduces towards the 1 0 outlet from the valve chamber.

2. A valve as in Claim 1 wherein there are two to five flow directors in the outlet flow path.

3. A valve as in Claim 1 wherein the flow directors comprise plates extending longitudinally in the outlet flow path. 1 5 4. A valve as in Claim 1 wherein the angle between a longitudinal line through the valve and the direction of longitudinal extent of the or each flow director on each side of a notional centre line of the valve or from an adjacent flow director is from 80 to 200. A valve as in Claim 4 wherein there are two flow directors and the angle between a notional centre line of the valve and the flow director on each side of it is about 100.

6. A valve as in Claim 4 wherein there are three flow directors and the angle between a centre flow director and the flow director on each side of it is about 100. 2 5 7. A valve as in Claim 4 wherein there are four flow directors and the angle between a notional centre line of the valve and the first flow director on each side of it is about 100 and the angle between the first flow director on each side and the second flow director on each side of it is about 100.

8. A valve as in Claim 4 wherein there are five flow directors and the 3 0 angle between a centre flow director and the first flow director on each side of it is about 100 and the angle between the first flow director on each side and the second flow director on each side of it is about 100. AMENDED SHEET (Article 34) (IPEA/AU) PCT/AU98/00684 Received 25 May 1999 9

9. A diaphragm valve of a type having a valve chamber, an inlet, an outlet, an inlet flow path and an outlet flow path and a diaphragm arrangement including a diaphragm adapted to enter the valve chamber to prevent flow through the diaphragm valve, the diaphragm valve being characterised by at least two flow directors in the outlet flow path whereby to improve flow through the valve and to reduce head loss across the valve, wherein the flow directors are angled to the direction of flow of the fluid in the valve so that the cross sectional area between adjacent flow directors reduces towards the outlet from the valve chamber. 1 0 10. A diaphragm valve as in Claim 9 wherein there are two to five flow directors in the outlet flow path.

11. A diaphragm valve as in Claim 9 wherein the flow directors comprise plates extending longitudinally in the outlet flow path.

12. A diaphragm valve as in Claim 9 wherein diaphragm valve body and 1 5 the flow directors are made as a single casting or moulding from plastics material, brass or cast iron.

13. A valve as in Claim 9 wherein the angle between a longitudinal line through the valve and the direction of longitudinal extent of the or each flow director on each side of a notional centre line of the valve or from an adjacent flow director is from 80 to 200.

14. A diaphragm valve as in Claim 13 wherein there are two flow directors and the angle between a notional centre line of the valve and the flow director on each side of it is about 100. A diaphragm valve as in Claim 13 wherein there are three flow directors and the angle between a centre flow director and the flow director on each side of it is about 100.

16. A diaphragm valve as in Claim 13 wherein there are four flow directors and the angle between a notional centre line of the valve and the first flow director on each side of it is about 100 and the angle between the first flow 3 0 director on each side and the second flow director on each side of it is about

100. AMENDED SHEET (Article 34) (IPEA/AU) -o" PCT/AU98/00684 Received 25 May 1999 17. A valve as in Claim 13 wherein there are five flow directors and the angle between a centre flow director and the first flow director on each side of it is about 100 and the angle between the first flow director on each side and the second flow director on each side of it is about 100. 18. A diaphragm valve as in Claim 9 further including at least one flow director on the inlet flow path. AMENDED SHEET (Article 34) (IPEA/AU)