AU2011201573B2

AU2011201573B2 - A Dual Action Flow Limiter Valve

Info

Publication number: AU2011201573B2
Application number: AU2011201573A
Authority: AU
Inventors: Warren A. Ewing; Robert A. Mclean
Original assignee: Mcwin Tech Pty Ltd
Current assignee: MCWIN TECHNOLOGY Pty Ltd
Priority date: 2010-04-07
Filing date: 2011-04-07
Publication date: 2016-01-14
Anticipated expiration: 2031-04-07
Also published as: NZ592133A; AU2011201573A1

Abstract

Abstract A dual action flow limit valve including a substantially tubular outer body having a first attachment portion at a first end thereof and a second attachment portion at a second, opposite end, an internal valve body located internally of the outer 5 body moveable between an open condition and a closed condition, biased into the closed condition such that attachment of a fitting to the outer body moves the internal valve body to the open condition and maintains the valve body in the open condition while attached. c00 <N I-r-

Description

AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION Standard Patent Invention Title: A DUAL ACTION FLOW LIMITER VALVE Applicant: McWin Technology Pty Ltd The invention is described in the following statement: 2 A DUAL ACTION FLOW LIMITER VALVE Field of the Invention. The present invention relates to valves and in particular flow control and limit valves for fluids. 5 Background Art. Currently, there are no devices that will allow the automatic operation of fitting once another product is attached to it. At present, many of the control devices such as a wide selection of taps or ceramic disc mixes are used to control water in a domestic or household environment. 10 With the movement towards the use of single lever ceramic disc mixing taps in kitchens and bathrooms, there is obviously an increase in the use of connecting stainless steel braided flexible hoses to these products. Flexible hoses have their own inherent operating problems in varying operating environments. These problems can be caused by varying flow rates and 15 massive pressure variants. For example, by day, the water pressure in an industrial area may be at a lower rate due to demand by many consumers while at night, the pressure may triple due to a decrease in use. Similarly, there is an increasing movement towards regulation flowrate through domestic taps. 20 Therefore, it would be an advance in the field if a fitting were provided to automatically shut off if the flowrate through the fitting were too high. It would also be an advance in the field if a test fitting were provided in order to allow an installer to test the availability of fluid in a pipe prior to connecting an outlet. 25 It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country. Summary of the Invention. The present invention is directed to a dual action flow limiter valve, 30 which may at least partially overcome at least one of the abovementioned disadvantages or provide the consumer with a useful or commercial choice. With the foregoing in view, the present invention in one form, resides broadly in a dual action flow limit valve including a substantially tubular outer body 3 having a first attachment portion at a first end thereof and a second attachment portion at a second, opposite end, an internal valve body located internally of the outer body moveable between an open condition and a closed condition, biased into the closed condition such that attachment of a fitting to the outer body moves the internal valve 5 body to the open condition and maintains the valve body in the open condition while attached. According to an alternative form, the invention resides in a dual action liquid flow limit valve including a substantially tubular outer body having a first attachment portion at a first end thereof and a second attachment portion at a second, 10 opposite end, an internal valve body located internally of the outer body moveable between an open condition and a closed condition, biased into the closed condition such that attachment of a fitting to the outer body moves the internal valve body to the open condition and maintains the valve body in the open condition while attached, a shutoff plunger moveable between an open condition and a closed condition and 15 biased into the open condition and a biasing means to bias the valve body and the shutoff plunger and adapted to allow movement of the shutoff plunger into the closed condition upon the imposition of a predetermined fluid flow rate through the valve. According to an further alternative form, the invention resides in a dual action liquid flow limit valve including a substantially tubular outer body having at 20 least one internally threaded portion at a first end thereof and an externally threaded portion at a second, opposite end, an internal valve body located internally of the outer body moveable between an open condition and a closed condition, biased into the closed condition such that attachment of a fitting to the outer body moves the internal valve body to the open condition and maintains the valve body in the open condition 25 while attached, a shutoff plunger moveable between an open condition and a closed condition and biased into the open condition and a biasing means to bias the valve body and the shutoff plunger and adapted to allow movement of the shutoff plunger into the closed condition upon the imposition of a predetermined fluid flow rate through the valve. 30 The double action liquid flow limit valve of the present invention has a dual purpose, namely: 1. providing a test connection point which is sealed until a hose or fitting is connected thereto; and 4 2. a flow limit function as the flow of fluid through the limit valve is shut off if the flowrate exceeds a predetermined maximum. The attachment of a hose or fitting to the flow limit valve of the present invention will preferably depress the internal valve body against the biasing action of 5 the biasing means in order to move the internal valve body to the open condition. This allows fluid to flow when a hose or fitting is connected to the flow limit valve and automatically shuts off flow through movement of the internal valve body, when the hose or fitting is disconnected, as the internal valve body moves to the closed condition under the biasing force of the biasing means. 10 The biasing means is a preferably double action biasing means, biasing the internal valve body closed and the shutoff plunger open, against each other. Importantly, a physical force applied by a fitting or hose attached to the outer body of the flow limit valve will preferably be partially received into the outer body to move and hold the internal valve body in the open condition but allows the shutoff plunger 15 to move if necessary, and on the condition that a sufficiently large force is applied to the shutoff plunger. The valve of the present invention includes a substantially tubular outer body. The outer body is normally manufactured from metal, typically brass, but may be manufactured from plastic, composite or another material. 20 The outer body will preferably have an externally threaded portion located at or adjacent one end and an internally threaded portion at or adjacent a second, opposite end. Normally, the externally threaded portion will be provided at an outlet end of the outer body and the internally threaded portion at an inlet end of the outer body. 25 The outer body will typically include a bore therethrough. Preferably, the bore will have a stepped profile. Typically, the stepped profile will narrow from the inlet end of the outer body to the outlet end of the outer body. According to a particularly preferred embodiment, the bore through the outer body will have a first large dimension bore portion at the inlet end of the outer body, a second, intermediate 30 dimension bore portion intermediate the outlet and inlet ends of the outer body and a third, smaller dimension bore portion at the outlet end of the outer body. There may be a tapered entry portion located at the outlet end of the outer body leading into the third, smaller dimension bore portion.

5 The bore is normally circular in cross-section along its length (albeit of different dimensions) but may have any cross-sectional shape. The particular portions of the stepped bore will preferably act to guide and limit the movement of the internal valve body and the shutoff plunger within the 5 outer body. Normally, the internal valve body and a shutoff plunger will be limited to reciprocal movement only, along an axis which is parallel to the direction of fluid flow through the outer body. Further, clearance between portions of the internal valve body, the shutoff plunger and the various portions of the stepped bore when the internal valve 10 body and a shutoff plunger are in the open condition will preferably allow fluid to flow through the outer body. The flow limit valve of the present invention includes an internal valve body located internally of the outer body and movable between an open condition and a closed condition, but biased into the closed condition. The internal valve body will 15 preferably correspond to the shape of the bore and therefore preferably be circular in cross-section. Normally, the internal valve body will be located within the outer body at the outlet end of the outer body. The internal valve body will preferably be located partially in the third, smaller dimension bore portion and partially in the second, 20 intermediate dimension bore portion of the outer body. The internal valve body will preferably have at least one, and normally a pair of circumferential sealing members, normally o-rings or similar. Preferably, a first sealing member is located on the internal valve body to seal the internal valve body against the third, smaller dimension bore portion and a second sealing member is 25 located on the internal valve body in order to seal the internal valve body in the closed condition. The second sealing member will preferably seal against the third, smaller dimension bore portion in order to prevent flow in the closed condition but be spaced from the third, smaller dimension bore portion when in the open condition. The internal valve body will preferably include a substantially planar 30 base portion and an annular portion located toward the outlet end of the outer body. The annular outer portion will typically be located at the outlet end of the outer body with the base portion located towards the inlet end of the outer body.

6 The annular outer portion will preferably have at least one and normally a plurality of openings in a side wall thereof. Normally, a part of the base portion of the internal valve body or a seal provided in association therewith will seal against the bore in order to prevent flow 5 but when a hose or fitting is attached to the outlet end of the valve, a portion of the hose or fitting will preferably be received partially within the bore in order to force the valve body away from the third, smaller bore portion allowing fluid to flow between the edge of the base portion of the internal valve body and a side wall of the bore, through the at least one opening in the annular side wall of the internal valve body and 10 out through the outlet end of the outer body. Each at least one opening in the internal valve body will preferably be a slot opening and normally, there will be at least two slot openings. Upstands are preferably provided from an upper surface of the base portion to an annular top ring, which together define the slot openings. Normally, the annular top ring also forms an 15 abutment surface for abutting a portion of the hose or fitting attached to the flow limit valve. The internal valve body may be manufactured from metal or plastic and is preferably dimensioned to be closely received in the bore of the outer body. An extension or protrusion (or other means) is preferably provided on a 20 lower/inner surface of the base portion of the internal valve body in order to positively locate the biasing means relative thereto. The flow limit valve of the present invention also preferably includes a shutoff plunger movable between an open condition and a closed condition and biased into the open condition. The shutoff plunger is also preferably circular in cross-section 25 in order to be closely received within the bore of the outer body. There is preferably an opening or depression (or other means) located in an outer surface of the shutoff plunger in order to receive a portion of the biasing means to positively locate the biasing means relative thereto. The shutoff plunger is preferably located in the first large dimension 30 bore portion and the second intermediate dimension bore portion of the outer body. Typically, a portion of the shutoff plunger or a sealing means provided relative thereto will seal against the second intermediate bore portion when the shutoff plunger is in the closed condition to prevent flow through the flow limit valve.

7 Typically, at least one circumferential seal member is provided on the shutoff plunger to form or assist with forming a seal when in the closed condition. Preferably, the shutoff plunger is biased against the internal valve body although independent biasing means may be provided. 5 The shutoff plunger may have a limit or stop means provided within the outer body in order to prevent or limit movement of the shutoff plunger beyond a point in the outer body, normally towards the inlet end of the outer body. As an example, a circlip may be used for this purpose. The shutoff plunger may be provided with a circular body portion 10 having a plurality of legs radiating outwardly from the centre thereof, on the inlet side of the outer body. Typically, the legs extend outwardly further than the circular body portion such that the circular body portion is received within the second, intermediate dimensioned portion of the bore and the legs are received within the first large dimensioned portion of the bore. 15 Normally, when in the open condition, a fluid flows into the outer body, outwardly between the legs and about the clearance provided in outer body between the wall of the bore and the circular body portion of the shutoff plunger. When a predetermined flowrate is reached, the force of the fluid on the shutoff plunger will preferably force the body and the associated seal means, toward 20 the outlet end of the outer body which will seal the shutoff valve against the second, intermediate dimension portion of the bore, normally by being forcibly received within this second intermediate dimension portion. Removal of the force of the fluid will preferably result in the biasing force of the biasing means asserting itself and forcing the shutoff plunger towards the inlet end and the open condition. 25 The flow limit valve of the present invention also typically includes a biasing means. The simplest form of biasing means is a biasing spring. Normally, the gauge of the biasing means can be adjusted to select the predetermined flowrate which will cause the shutoff plunger to move to the closed condition, with a higher biasing force resulting in a high a predetermined flowrate before shutoff. 30 Any of the features described herein can be combined in any combination with any one or more of the other features described herein within the scope of the invention. Brief Description of the Drawings.

8 Various embodiments of the invention will be described with reference to the following drawings, in which: Figure 1 is a front view of a flow limit valve according to a preferred embodiment of the present invention. 5 Figure 2 is a side view of the flow limit valve as illustrated in Figure 1. Figure 3 is an end view of the flow limit valve illustrated in Figure 1. Figure 4 is an end view of the flow limit valve illustrated in Figure 2. Figure 5 is a sectional front view of the flow limit valve illustrated in Figure 1 along line A-A illustrated in Figure 3. 10 Figure 6 is a sectional side view of the flow limit valve illustrated in Figure 2 along line B-B illustrated in Figure 4. Figure 7 is an exploded axonometric view of the flow limit valve illustrated in the preceding figures. Figure 8 is an end view of a flow limit valve according to a preferred 15 embodiment from the outlet end. Figure 9 is a side view of the flow limit valve illustrated in Figure 1. Figure 10 is a sectional side view of the flow limit valve illustrated in Figure 9 along line A-A. Figure I1 is a detailed side view of a portion of the side wall of the 20 flow limit valve illustrated in Figure 10. Figure 12 is an end view of a flow limit valve according to a preferred embodiment from the inlet end. Figure 13 is an axonometric sectional view of the flow limit valve illustrated in Figure 10. 25 Figure 14 is a side view of an internal valve body according to a preferred embodiment of the present invention and a sectional view along line D-D. Figure 15 is a bottom and side view of an internal valve body according to a preferred embodiment of the present invention. Figure 16 is a sectional view of the internal valve body illustrated in 30 Figure 15 along line B-B. Figure 17 is an axonometric view of an internal valve body according to a preferred embodiment. Figure 18 is a view from above of a shutoff plunger according to a 9 preferred embodiment of the present invention. Figure 19 is a sectional side view of the shutoff plunger illustrated in Figure 18 along line C-C. Figure 20 is an axonometric view of a shutoff plunger according to a 5 preferred embodiment. Detailed Description of the Preferred Embodiment. According to a particularly preferred embodiment of the present invention, a dual action flow limit valve 10 is provided. The dual action flow limit valve 10 illustrated in the Figures includes a 10 substantially tubular outer body 11 having an internally threaded portion 12 at an inlet end thereof and an externally threaded portion 13 at a second, outlet end. The flow limit valve 10 also includes an internal valve body 14 located internally of the outer body 11 moveable between an open condition and a closed condition and biased into the closed condition such that attachment of a fitting to the 15 outer body 11 moves the internal valve body 14 to the open condition and maintains the valve body 14 in the open condition while attached. Further, a shutoff plunger 15 is provided internally of the outer body 11 moveable between an open condition and a closed condition and biased into the open condition. 20 According to the illustrated embodiment, a biasing spring 16 is provided to bias the valve body 14 and the shutoff plunger 15 into the respective conditions and adapted to allow movement of the shutoff plunger 15 into the closed condition upon the imposition of a predetermined fluid flow rate through the flow limit valve 10. 25 The outer body 11 is normally manufactured from metal, typically brass. As best illustrated in Figure 10, the outer body 11 includes a bore 17 therethrough. The bore 17 has a stepped profile, narrowing from the inlet end of the outer body 11 to the outlet end of the outer body 11. According to the preferred 30 embodiment illustrated, the bore 17 through the outer body will have a first large dimension bore portion 18 at the inlet end of the outer body 11, a second, intermediate dimension bore portion 19 intermediate the outlet and inlet end of the outer body 11 and a third, smaller dimension bore portion 20 at the outlet end of the outer body 11.

10 There is also a tapered entry portion 21 located at the outlet end of the outer body 11 leading into the third, smaller dimension bore portion 20. The particular portions of the stepped bore 17 act to guide and limit the movement of the internal valve body 14 and the shutoff plunger 15 within the outer 5 body 11. Normally, the internal valve body 14 and a shutoff plunger 15 will be limited to reciprocal movement only along an axis which is parallel to the direction of flow through the outer body 11. Further, clearance between portions of the internal valve body 14, the shutoff plunger 15 and the various portions of the stepped bore 17 when the internal 10 valve body 14 and a shutoff plunger 15 are in the open condition allow fluid to flow through the outer body 11. The internal valve body 14 corresponds to the shape of the bore 17 and therefore is preferably be circular in cross-section. As illustrated in Figures 5 and 6 particularly, the internal valve body 14 15 is located within the outer body 11 at the outlet end of the outer body 11 partially in the third, smaller dimension bore portion 20 and partially in the second, intermediate dimension bore portion 19 of the outer body 11. The internal valve body 14 illustrated has a pair of circumferential sealing members, normally o-rings or similar. A first outer sealing member 22 is 20 located on the internal valve body 14 to seal the internal valve body 14 against the third, smaller dimension bore portion 20 and a second sealing member 23 is located on the internal valve body 14 in order to seal the internal valve body 14 in the closed condition. The second sealing member 23 seals against the third, smaller dimension bore portion 29 in order to prevent flow in the closed condition. 25 More particularly illustrated in Figures 14 to 17, the internal valve body 14 includes a substantially planar base portion 24 and an annular outer portion 25. The annular outer portion 25 is located at the outlet end of the outer body 11 with the base portion 24 located towards the inlet end of the outer body 11. The annular outer portion 25 has a pair of slot openings 28 in a side 30 wall thereof. Upstands 26 are provided from an upper surface of the base portion 24 to an annular top ring 27 which together define the slot openings 28. Normally, the annular top ring 27 also forms an abutment surface for abutting a portion of the hose or fitting attached to the flow limit valve 10.

11 Normally, a part of the base portion 24 or the second sealing member 23 of the internal valve body 14 will seal against the bore 17 in order to prevent flow, but when a hose or fitting is attached to the outlet end, a portion of the hose or fitting is received partially within the bore 17 in order to force the valve body 14 a way from 5 the third, smaller bore portion 20 allowing fluid to flow between the edge of the base portion 24 of the internal valve body 14 and a side wall of the bore 17, through the slot openings 28 in the annular side wall of the internal valve body 14 and out through the outlet end of the outer body 11. An extension or protrusion 29 is provided on a lower surface of the 10 base portion 24 of the internal valve body 14 in order to positively locate the biasing spring 16 relative thereto. Seats are also provided for the sealing members as illustrated in Figure 16. As illustrated in Figures 18 to 20 in particular, the shutoff plunger 15 is also preferably circular in cross-section in order to be closely received within the bore 15 17 of the outer body 11. There is an opening or depression 30 located in an outer surface of the shutoff plunger 15 in order to receive a portion of the biasing spring 16 to positively locate the biasing spring 16 relative thereto. The shutoff plunger 15 is located in the first large dimension bore 20 portion 18 and the second intermediate dimension bore portion 19 of the outer body 11. Typically, a portion of the shutoff plunger 15 or a circumferential sealing means 31 provided relative thereto seals against the second intermediate bore portion 19 when the shutoff plunger 15 is in the closed condition (Figure 5) to prevent flow through the flow limit valve 10. The shutoff plunger 15 in the open condition is 25 illustrated in Figure 6. As illustrated in Figures 5 and 6, the shutoff plunger 15 is typically biased against the internal valve body 14. The shutoff plunger 15 has a limit or stop means provided within the outer body in order to prevent or limit movement of the shutoff plunger 15 beyond a 30 point in the outer body 11, normally towards the inlet end of the outer body. In the illustrated embodiment, a circlip 32 is used for this purpose. The circlip 32 is seated in a circumferential groove in the bore of the outer body as illustrated in Figure 11.

12 The shutoff plunger 15 has a circular body portion 33 having a plurality of legs 34 radiating outwardly from the centre thereof, on the inlet side of the outer body 11. The legs 34 extend outwardly further than the circular body portion 33 such that the circular body portion 33 is received within the second, intermediate 5 dimensioned portion 19 of the bore 17 and the legs 34are received in within the first large dimensioned portion 18 of the bore, as illustrated in Figure 5 in particular to limit the outward movement of the shutoff plunger 15. Normally, when in the open condition, a fluid flows into the outer body 11, outwardly between the legs 34 and about the clearance provided in outer body I 1 10 between the wall of the bore 17 and the circular body portion 33 of the shutoff plunger 15. When a predetermined flowrate is reached, the force of the fluid on the shutoff plunger 15 forces the shutoff plunger 15 and the associated seal 31 toward the outlet end of the outer body 11 which seals the shutoff valve 15 against the second, 15 intermediate dimension portion 19 of the bore 17, normally by being forcefully received within this second intermediate dimension portion 19. Removal of the force of the fluid results in the biasing force of the biasing spring 16 asserting itself and forcing the shutoff plunger 15 towards the inlet end and the open condition. The gauge of the biasing spring 16 can be adjusted to select the 20 predetermined flowrate which will cause the shutoff plunger 15 to move to the closed condition, with a higher biasing force resulting in a higher predetermined flowrate before shutoff. The double action liquid flow limit valve 10 of the present invention therefore has a dual purpose, namely: 25 1. providing a test connection point which is sealed until a hose or fitting is connected thereto; and 2. a flow limit function as the flow of fluid through the limit valve is shut off if the flowrate exceeds a predetermined maximum. The attachment of a hose or fitting to the flow limit valve 10 of the 30 present invention depresses the internal valve body 14 against the biasing action of the biasing spring 16 in order to move the internal valve body 14 to the open condition. This allows fluid to flow when a hose or fitting is connected to the flow limit valve 10 and automatically shuts off flow through movement of the internal valve body 14 13 when the hose or fitting is disconnected as the valve body 14 moves to the closed condition under the biasing force of the biasing spring 16. As mentioned above, the biasing spring 16 of the illustrated embodiment is a double action biasing means, biasing the internal valve body 14 5 closed and the shut off plunger 15 open against each other. Importantly, a physical force applied by the fitting attached to the outer body 11 of the flow limit valve holds the internal valve body 14 in the open condition but allows the shutoff plunger 15 to move if necessary and on the condition that a sufficiently large force is applied to the shutoff plunger 15. 10 Any of the features described herein can be combined in any combination with any one or more of the other features described herein within the scope of the invention. In the present specification and claims (if any), the word "comprising" and its derivatives including "comprises" and "comprise" include each of the stated 15 integers but does not exclude the inclusion of one or more further integers. Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases "in one embodiment" or "in an 20 embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations. In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be 25 understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims (if any) appropriately interpreted by those skilled in the art. 30

Claims

1. A dual action liquid flow limit valve including: a substantially tubular outer body having: a first attachment portion at a first end thereof, and 5 a second attachment portion at a second, opposite end; an internal valve body located internally of the outer body moveable between an open condition and a closed condition, biased into the closed condition such that attachment of a fitting to the outer body moves the internal valve body to the open condition and maintains the valve body in the open condition while 10 attached; a shutoff plunger moveable between an open condition and a closed condition defined by a limit or stop shoulder provided in an internal sidewall of the outer body in order to limit movement of the shutoff plunger in a direction of the fluid flow and biased into the open condition; 15 a biasing means to bias the valve body and the shutoff plunger against each other and adapted to allow movement of the shutoff plunger into the closed condition upon the imposition of a predetermined fluid flow rate through the valve; and, 20 wherein abutment of the shutoff plunger with the limit or stop shoulder seals the shutoff valve once the predetermined fluid flow rate is reached.

2. A dual action liquid flow limit valve including: a substantially tubular outer body having: at least one internally threaded portion at a first end thereof and 25 an externally threaded portion at a second, opposite end, an internal valve body located internally of the outer body moveable between an open condition and a closed condition, biased into the closed condition such that attachment of a fitting to the outer body moves the internal valve body to the open condition and maintains the valve body in the open condition while 30 attached, a shutoff plunger moveable between an open condition and a closed condition defined by a limit or stop shoulder provided in an internal sidewall of the outer body in order to limit movement of the shutoff plunger in a direction of the fluid flow and biased into the open condition; 15 a biasing means to bias the valve body and the shutoff plunger against each other and adapted to allow movement of the shutoff plunger into the closed condition upon the imposition of a predetermined fluid flow rate through the valve; and, 5 wherein abutment of the shutoff plunger with the limit or stop shoulder seals the shutoff valve once the predetermined fluid flow rate is reached.

3. A dual action liquid flow limit valve as claimed in either one of claims 1 or 2 wherein the biasing means is a double action biasing means, biasing the internal valve body closed and the shutoff plunger open, against each other. 10

4. A dual action liquid flow limit valve as claimed in any one of claims 1 to 3 wherein the outer body includes a bore with a stepped profile therethrough.

5. A dual action liquid flow limit valve as claimed in claim 4 wherein the bore through the outer body has a first large dimension bore portion at the inlet end of the outer body, a second, intermediate dimension bore portion intermediate the 15 outlet and inlet ends of the outer body and a third, smaller dimension bore portion at the outlet end of the outer body.

6. A dual action liquid flow limit valve as claimed in claim 4 or claim 5 wherein the stepped bore profile of the bore acts to guide and limit the movement of the internal valve body and the shutoff plunger within the outer body. 20

7. A dual action liquid flow limit valve as claimed in any one of claims 4 to 6 wherein the internal valve body and a shutoff plunger are limited to reciprocal movement only, along an axis which is parallel to the direction of fluid flow through the outer body.

8. A dual action liquid flow limit valve as claimed in any one of claims 4 to 7 25 wherein clearance between portions of the internal valve body, the shutoff plunger and the stepped bore when the internal valve body and a shutoff plunger are in the open condition allows fluid to flow through the outer body.

9. A dual action liquid flow limit valve as claimed in any one of claims 1 to 8 wherein the internal valve body is located within the outer body at the outlet end 30 of the outer body.

10. A dual action liquid flow limit valve as claimed in any one of claims 1 to 9 wherein the internal valve body includes a substantially planar base portion and an annular portion located toward the outlet end of the outer body with the base portion located towards the inlet end of the outer body. 16

11. A dual action liquid flow limit valve as claimed in claim 10 wherein a part of the base portion of the internal valve body or a seal provided in association therewith sealingly engages against the bore in order to prevent flow but when a hose or fitting is attached to the outlet end of the valve, a portion of the hose or fitting is 5 received partially within the bore in order to force the valve body out of sealing engagement.

12. A dual action liquid flow limit valve as claimed in either one of claims 10 or 11 wherein the annular outer portion has at least one opening in a side wall thereof.

13. A dual action liquid flow limit valve as claimed in any one of claims 10 to 12 10 wherein an extension or protrusion is provided on a lower/inner surface of the base portion of the internal valve body in order to positively locate the biasing means relative thereto.

14. A dual action liquid flow limit valve as claimed in any one of claims 1 to 13 wherein an opening or depression is provided in an outer surface of the shutoff 15 plunger in order to receive a portion of the biasing means to positively locate the biasing means relative thereto.

15. A dual action liquid flow limit valve as claimed in any one of claims 1 to 14 wherein the shutoff plunger has a limit or stop means provided within the outer body in order to prevent or limit movement of the shutoff plunger in a direction 20 opposite to the fluid flow beyond a point in the outer body.

16. A dual action liquid flow limit valve as claimed in any one of claims 1 to 15 wherein when a predetermined flowrate is reached, the force of the fluid on the shutoff plunger forces the body and any associated seal means, toward the outlet end of the outer body which seals the shutoff valve and removal of the force of 25 the fluid results in the biasing force of the biasing means asserting itself and forcing the shutoff plunger towards the inlet end and the open condition.

17. A dual action liquid flow limit valve as claimed in any one of claims 1 to 16 wherein the biasing means is a biasing spring and the gauge of the biasing spring can be adjusted to select the predetermined flowrate to cause the shutoff plunger 30 to move to the closed condition.