AU2022201888B1

AU2022201888B1 - A float valve with a transient mitigation function.

Info

Publication number: AU2022201888B1
Application number: AU2022201888A
Authority: AU
Inventors: Raghunath Prabhu; Mark Valkenburg; Stuart Watson
Original assignee: Philmac Pty Ltd
Current assignee: Philmac Pty Ltd
Priority date: 2022-03-18
Filing date: 2022-03-18
Publication date: 2023-02-02
Anticipated expiration: 2042-03-18
Also published as: IE20230061A2

Abstract

The present invention is a float valve that is capable to mitigate transients during operation by limiting the oscillation with the introduction of a mechanical bias. The float valve also consists of a self-cleaning function that helps discharge mud and silt from the valve body to prevent fouling.

Description

A float valve with a transient mitigation function.

FIELD OF THE INVENTION

[0001] The present invention relates to an equilibrium float valve that mitigates transients and

is also capable to self-clean its internal components.

BACKGROUND TO THE INVENTION

[0002] Float valves have been commonly used within the water industry as a mechanical

method to control the level of water in a tank. Float valves have various types of internal mechanics,

one form that would be commonly observed is the equilibrium diaphragm float valve which can be

found in most toilet cisterns.

[0003] Float valves commonly have a float attached to a lever that extends out from the body,

the float is buoyant and sits on the surface of the liquid. As the liquid level drops, the float will drop

and once at a pre-set position open a valve to discharge liquid into the tank until the float returns to

a pre-set closed position. This allows the tank to operate without the need for an operator.

[0004] When a float valve is discharging into the tank, the liquid surface is disrupted and waves

are introduced into the tank. Waves that are introduced into the tank cause the float to track the

disruptive surface, this potentially causes the float valve to constantly switch from an open to close

state until the water surface becomes steady. The constant changes in the surface of the water

cause the float valve to introduce transients into the pipe network.

[0005] Transients entering into the network are known to cause damage to a water network

since the pressure can exceed the designed pressure limit, transients can cause movement of the

pipe accelerating wear, and bursting weaker and deteriorated sections of the pipe network.

[0006] Other float valve devices have attempted to mitigate transients through the reduction

of the discharge orifice size to reduce the amplitude of the transients.

[0007] Float valves are commonly used with raw water systems that contain silt and mud. The

presence of silt and mud in the water column is commonly attributed to the blocking of pilot holes,

once the pilot hole is blocked the valve will malfunction in several ways including not closing.

[0008] It is an aim of this invention to propose a float valve that can mitigate transients with a

biasing mechanism, the float valve also preferentially including a self-cleaning function that prevents

or reduces pilot hole blockage.

SUMMARY OF THE INVENTION

[0009] In a first aspect of the invention there is proposed a float valve, comprising of at least

one inlet and outlet, a diaphragm, a diaphragm button, a float arm, a float, and a biasing mechanism

to mitigate transients.

[0010] In preference, the float valve consists of a biasing mechanism that controls the speed of

the float arm preventing high-frequency movements during non-steady surface states in a tank.

[0011] In preference, a cover over the float arm protects it from impact and damage.

[0012] In preference, the float valve discharge consists of vanes that ensure the discharge is

directed downwards into the tank.

[0013] In preference, a float valve with a diaphragm that changes its operational status from

open to close in response to the pressure differences in the valves front and rear chambers.

[0014] It should be noted that any one of the aspects mentioned above may include any of the

features of any of the other aspects mentioned above and may include any of the features of any of

the embodiments described below as appropriate.

[0015] The object of this invention is to provide a system and method to address the above

shortcomings or at least provides the public with a useful alternative.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Preferred features, embodiments and variations of the invention may be discerned

from the following Detailed Description which provides sufficient information for those skilled in the

art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of

the preceding Summary of the Invention in any way. The Detailed Description will make reference to

a number of drawings as follows.

[0017] Figure 1 illustrates a cross-sectional view of a float valve in the closed state according to

a first embodiment;

[0018] Figure 2 illustrates in a cross-sectional view of the float valve of Figure 1 when in an

open state;

[0019] Figure 3 is an underside perspective view of the float valve;

[0020] Figure 4 is a left perspective view of the float valve;

[0021] Figure 5 is a perspective view of the inside of the front housing;

[0022] Figure 6 is a perspective view of the inside of the rear housing;

[0023] Figure 7 is a partial perspective right-hand side view of the float valve without a float arm guard in the closed state;

[0024] Figure 8 is a partial perspective right-hand side view of the float valve without a float arm guard in the open state;

[0025] Figure 9 is the float valve with an extended float arm and two floats attached; and

[0026] Figure 10 demonstrates the various means the float valve can be fitted to a tank, either above or below the water surface.

DETAILED DESCRIPTION OF THE INVENTION

[0027] The diaphragm float valve 10 comprises a rear housing 20, front housing 30, diaphragm 41, float arm 50, float 60, and a transient mitigation mechanism in the form of a biasing mechanism 51.

[0028] Firstly, the pipe size and operation conditions are taken into consideration in regards to the size of the float valve 10 that will be used. The float valve 10 can be used for a variety of size pipes such as but not limited to 4mm to 3000mm in diameter. The pressure conditions the float valve 10 can operate in are between but not limited to 0.1 bar to 1000bar.

[0029] The float valve 10 is commonly used in a tank or open body of water to manage the water height and prevent overflows. A typical use for a float valve is for water troughs used for livestock. An example of use can be observed in Figure 10.

[0030] The float valve 10 is connected to a pipe network (not shown), by threads 22 connecting the rear housing 20 into the pipe network. Alternatively, the rear housing 20 can be connected to the pipe network using a variety of fastening systems such as but not limited to cam lock or flanged. The methods that are discussed above to fasten the rear housing 20 to the network are not limiting.

[0031] An O-ring 24 is present on the rear housing at the end of the threaded section 22, the O-ring 24 acts to seal the rear housing 20 with other fittings. The O-ring 24 is also used to form a seal against a tank wall 70 (Figure 10) if the float valve 10 is positioned under the surface of the water, an example of submerged float valve 10 illustrated in Figure 10. The O-ring 24 forms a seal between the rear housing 20 and the tank wall 70 as the rear housing 20 is threaded using threads 22 onto the tank wall 70. The O-ring 24 forms the seal by compressing between the two surfaces 20, 70. Other forms of sealing can be used such as gasket rings and liquid seals.

[0032] The rear housing 20 comprises inlet 23 where the water from the network can be fed

into. The diameter of the inlet 23 matches the fluid networks pipe diameter.

[0033] The outlet 21for the float valve 10 is located on the lower section of the rear housing

20. The size of the outlet 21 can be but not limited to the same width of the rear body 20, or a

smaller diameter with a section on the end that can allow fittings to be attached. The outlet 21

includes vanes 28 (Figure 3) that are designed with straightening the discharge from the float valve

, the vanes 28 preventing or minimising disruption to the water surface.

[0034] On the inner surface of the rear housing 20, multiple blades 26 protrude from the inner

wall partially into the centre of the rear housing 20, an example of the blade 26 arrangement

illustrated in Figure 6. The blades 26 assist with holding the diaphragm 41 in place and strengthening

the rear housing 20. Alternatively, blades can also be placed on the outer surface to strengthen the

rear housing 20.

[0035] The rear housing 20 comprises multiple locking tabs 25 present on the outer

circumference of the open end of the rear housing 20. The locking tabs 25 protrude outwardly from the housing that has a slight taper 27 on one face that gently extends outwardly into a higher

section. The tabs 25 are made to fit into the front housing 30 collocated locking tab holes 34. The

locking tab holes 34 allow the front housing 30 to be secured onto the rear housing 20 by aligning

the front housings tabs 25 with the rear housings tab holes 34 and rotating it until housings 20, 30

lock into each other. As the housings 20, 30 are rotated to engage each other, the taper 27 on the

tabs 25 forms an interference fit. Though other forms of fixing the front housing 30 to the rear

housing 20 can also be undertaken such as threading or fastening the housings together.

[0036] Once the front 30 and rear housing 20 have been connected a fastening pin 38 is placed

through both of the housing 20, 30 through a collocated hole 39, the pin 38 locks and prevents the

housing from rotating and separating from each other. Alternatively, a fastener can also be used to

secure the front 30 and rear housing 20 together.

[0037] The front housing 30 contains the diaphragm 41. The diaphragm 41 is circular with a

folded section inner circumference and a raised inner cup that protrudes towards the rear housing

20. The folded section on the diaphragm 41 allows the centre raised portion to move forwards and

backward under pressure. The diaphragm 41 though can be in other shapes such as but not limited

to a flexible cup, flat disc, or square.

[0038] The diaphragm 41 is made of a soft waterproof material, as an example but not limited

to it and can, for example, be in the form of rubber or silicon.

[0039] The diaphragm 41 is fixed to a centre disc 46 and comprises a small circular button 42.

The centre disc 46 and the button 42 both have a centre orifice that helps align and retains the

diaphragm on the front housing guiding pin 35. The front housing guiding pin 35 allows the

diaphragm 41 to move in a set direction and prevents the diaphragm 41from moving around. The

centre disc 46 and the button 42 are fastened to the raised portion of the diaphragm 41, though the

diaphragm 41 can be made in a single piece with the centre disc 46 and button 42 cast into it.

[0040] The button 42 has a small orifice that provides the pressure differential function of the

valve and that allows mud and silt to be discharged out of the valve body through an orifice on the

front housing 33 when the valve is in an open state, this is as a self-cleaning function for the rear end

of the diaphragm 41. The self-cleaning function mitigates fouling in the front housing 30 behind the

diaphragm 41. The surface adjacent to the orifice in the button 42 is shaped to prevent or minimise

the risk of contaminant particles that are too large to flow through the orifice from blocking said

orifice. The button 42 shape can take many forms in order to use the flow of the water to self-flush

the orifice and prevent blocking.

[0041] The diaphragm 41 is also retained in place using a retaining disc 40. The retaining disc

is a circular ring that holds downs the diaphragm 41in place and prevents it from entering too far

into the rear housing 20, this is achieved by the retaining disc 40 seating against the rear housings 20

blades 24. When the diaphragm 41is secured down by the retaining disc 40 the diaphragm forms a

seal with the front housing 30.

[0042] The main function of the diaphragm 41 is to control the two operational modes of the

valve, open and close. These operations modes are controlled by the float arm 50 movement that

tracks the liquid height.

[0043] The float arm 50 is secured to the front housing 30 via a pin 36. The pin 36 is inserted

into collocated holes on the float arm 50 and the front housing 30. On one end of the pin 36 has a

head 31, and on the other end a hole is present (not shown). As the pin 36 is inserted into the

collocated holes on the front arm 50 and the front housing 30, the pin is pushed in until the head 31 abuts against the surface of the collocated hole. The pin 36 is held in place with an R-clip 32 that is pushed into a hole on the pin 36 that is exposed on the other side of the collocated hole, the R-clip

32 forms an interference with the hole 36

[0044] The pin 36 used to attached the float arm 50 to the front housing 30 can be fed either

into the front 57 or rear 58 position pinholes on the float arm 50. The front 57 and rear 58 position

pinholes allow the float arm 50 to be positioned either protruding outwards or over the front

housing as shown in Figure 10.

[0045] As the pin 36 is fed through the front arm 50 and the front housing 30, it may also be

fed through a front guard 53. The front guard 53 helps protect the C-spring clip 51 and orifice 33

from damage and debris.

[0046] The C-spring clip 51 is fastened into the top of the float arm 50 under the retainer 59 on

the top of the float arm 50, and is fastened to the front housing 30 by inserting the two ends of the

C-spring 51into the corresponding holes 37 on the front housing.

[0047] The float 60 is located at the end of the float arm 50, the float 60 is made of buoyant

material or hollow vessel allowing it to float on the top of the liquid surface.

[0048] The float 60 is connected to the float arm 50 via a pin 61, though it can be fastened in

place with fasteners. The float arm 50 is an extended shaft that connects the float 60 to the body of

the float valve 10. The float arm 50 is secured to the front housing 30 by a pin 36 that acts as a hinge, this allows the float arm 50 to move and track the water surface height.

[0049] The float arm 50 length is dependent on the distance of the float valve 10, the angle of

the float arm 50, and the distance to the surface of the water. The float arm 50 length can be but is

not limited to 10mm to 2000mm. If the float valve 10 is located below the surface a cord 56 can be

connected to the end of the float arm 50 extending it to the surface as shown in Figure 10.

[0050] The float arm 50 is angled from the body of the device, the angle aids with reducing the

pressure required to seal the front housings outer orifice 33.

[0051] Other forms of float arms 50 can also be used such as an extension 55 that allows an

additional lower float 60 to be added, an example of this can be observed in Figure 9. The extension

is threaded onto float arm 50 with a fastener 62, though a whole new single piece extended arm

can also be used. A cord 56 is used when the float valve 10 is positioned under the surface of the water as shown in Figure 10. The cord 56 is fastened to the end of the float arm 50 and the float 60.

[0052] The water level height determines the two states of the float valve 10, open and closed.

[0053] When the float valve 10 is in the closed state, the float arm 50 is raised due to the float

sitting on the top of the water surface at the desired level. With the float arm 50 raised the

sealing rubber 52 is pushed up against the front housing 30 sealing the front housing orifice 33. Once

the front housing orifice 33 is sealed, the front housing 30 is pressurised by water flowing through the orifice on the button 42 and behind the diaphragm 41. The water pressure behind the

diaphragm 41 pushes the diaphragm 41 centre towards the rear housing orifice 23 and forms a seal.

Due to the pressure in the front housing 30 from the water network, and no pressure in rear housing

due to an open outlet 21, the force from the water supply pressure is unable to overcome the

pressure in the front housing 30 forcing the diaphragm seal closed. The diaphragm 41 is now sealed

against the rear housing orifice 23 preventing the flow of water. An example of this can be observed

in Figure 1.

[0054] The float valve 10 is in an open state when the float arm 50 moves down. As the float

arm 50 drops the front housing orifice 33 is no longer sealed by the rubber seal 52. The pressure in

the rear housing 20 from the water network can now push the diaphragm 41 backwards into the

front housing 30. Now there is a clear path for water to flow from the rear housings orifice 23

through to the outlet 21. An example of this can be observed in Figure 2.

[0055] The movement speed of the float arm is controlled by the C-spring clip 51. The C- spring

clip 51 requires a minimum amount of pressure to allow the float arm 50 to move. This prevents the

float arm 50 from tracking the water surface easily when it is disturbed during an open state event

from the float valve 10.

[0056] The biasing mechanism prevents the float arm 50 from oscillating and creating

transients while the float valve 10 is discharging water into the tank. Commonly when a float valve

allows water to discharge into a tank it creates waves by disrupting the liquid surface, this causes the

float arm 50 to move up and down rapidly and change the state of the valve from open to closed in

an oscillating manner until the surface enters a steady state. Due to this frequent closing and

opening of the valve orifice, the float valve 10 can introduce transients into the water main.

[0057] The biasing mechanisms can be in the form of a device that is capable to reduce the

speed of the float arm 50 but still allows full movement. It would be common for a spring, cam, or

gas strut to be used within this situation, though is not limited to these three forms of biasing mechanical devices. Depending on the biasing mechanisms used, the effects of the biasing mechanisms on the movement of the float arm 50 may differ. The biasing mechanism regardless of the type used will be capable of dampening, decreasing, diminishing, lowering, moderating, suppressing, or absorbing shock from the movement of the float arm 50 due to the movement of the float 60 in the water tank.

[0058] The biasing mechanism mitigates transients' by reducing the oscillation of the float arm

movements. Reducing the oscillation frequency of the float arm 50 movements reduces the closing speed of the outlet 21. By reducing the closing speed of the orifice 21, the amplitude and the

sharpness of the transient wavefront are reduced if not eliminated.

[0059] The transient wave will also be diminished by the diaphragm 41 and the material used

in the body of the float valve 10. Rubber and plastic have a low Young's modulus, materials with a

low Young's modulus are known for the absorption of transient wave energy.

[0060] The float valve 10 can be used above or below the water level as shown in Figure 10.

For example, if the float valve 10 is used above water level the float valve 10 will be positioned

above the water line and the float 60 will sit at the desired level to trigger the open and closed state.

If the float valve 10 is positioned under the water level, a cord 56 can be used to locate the float 60

at the desired height.

[0061] The orifice 23 of the rear housing can also consist of a limiting valve or smaller orifice

size. Limiting the size of the discharge orifice can help reduce the size of the transient generated

when the float valve 10 enters into a closed state. The reduction of the flow will also reduce the

volume that is discharged when the float valve 10 is in its open state, this will also reduce the

disruption to the water surface and will help mitigate the oscillations of the float arm 50.

[0062] The float valve 10 can be made from various rigid materials, though it is preferably

made of acetal.

[0063] The reader will now appreciate the present invention which provides a float valve that

is capable to mitigate transients during operational conditions and the self-cleaning function.

LIST OF COMPONENTS

[0064] The drawings include the following integers.

- Float valve device

- Rear housing

21- Outlet

22 - Rear housing outer threads

23 - Rear housing inner orifice

24 - O-ring

- Front housing locking tabs

26 - Inner blades

27- Taperon the tabs

28- Vanes

- Front housing

31- Enlarged end of the pin

32 - Float arm pin R-Clip

33 - Front housing orifice

34 - Locking tab hole

- Front housing guide pin

36 - Float arm pin

37 - C-spring holes

38 - Housing pin

39 - Housing pinhole

- Diaphragm retention disc

41- Diaphragm

42 - Diaphragm button

46 - Diaphragm plate

- Float arm

51- C-spring clip

52 - Front Orifice seal

53 - Arm cover

- Extension arm

56 - Cord

57 - Reverse pin orifice

58 - Forward pin orifice

59 - Spring retainer

- Float

61 - Pin

62 - Float arm fastener

-Tank wall

[0065] Further advantages and improvements may very well be made to the present invention

without deviating from its scope. Although the invention has been shown and described in what is

conceived to be the most practical and preferred embodiment, it is recognized that departures may

be made therefrom within the scope of the invention, which is not to be limited to the details

disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all

equivalent devices and apparatus. Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of the

common general knowledge in this field.

[0066] In the present specification and claims (if any), the word "comprising" and its

derivatives including "comprises" and "comprise" include each of the stated integers but does not

exclude the inclusion of one or more further integers.

Claims

1. A diaphragm float valve with transient mitigator for use in a water tank comprising of:

a. at least one inlet and outlet that allows water to communicate through the float

valve;

b. a sealing member that controls the water flow between the inlet and outlet;

c. a hinged lever connected to the float valve; d. a buoyant device that is located in the water tank;

e. a biasing means to control a movement of the hinged lever by providing a delay in

the movement of, and preventing repeated oscillation of said hinged lever, in

response to a change in a water level in the tank; and

f. wherein delayed movement of the hinged lever prevents immediate opening and

closing of the valve.

2. The float valve as in claim 1, wherein the biasing means is a spring.

3. The float valve as in claim 1, wherein the biasing means is a gas strut.

4. The float valve as in claim 1, wherein the biasing means is a cam.

5. The float valve as in claim 1 wherein the hinged lever comprises a cover.

6. The float valve as in claim 1 wherein the outlet comprises of vanes in an outlet orifice.

7. The float valve as in claim 1 wherein the sealing member comprises of a hole that allows

water to pass through and clean the float valve 8. The float valve as in claim 7, wherein the sealing member is made of a flexible material.

9. The float valve as in claim 7, wherein the hole can allow fluid to travel through the float

valve to assist in cleaning internal components of the valve.

10. The float valve as claimed in claim 9, wherein the hole is shaped so as to deflect large

particles from blocking the hole.

11. The float valve as in claim 1, wherein the sealing member operates in response to a pressure

differential.

12. A diaphragm float valve with transient mitigator for use in a water tank comprising of:

valve;

b. a sealing member that controls the water flow between the inlet and outlet;

c. a hinged lever connected to the float valve and a buoyant device that is located in

the water tank, wherein the movement of said lever and buoyant device in response

to changes in the level of the water is employed to control the operation of the float valve; d. a biasing means to control said movement of the hinged lever in order to overcome common problems associated with float valves including: i. bouncing of the buoyant device on closing which causes water hammer and damage to associated equipment (pipes, etc); ii. immediate opening of the valve as soon as the water level drops a very small amount even due to a surface wave, which can cause damage to supply pump equipment; iii. very slow closing of the valve when the water level approaches its maximum; and e. said biasing means to make use of an over-top-dead-centre to profile the forces applied by the biasing means to moderate closing and opening of the valve.