AU2023201549B1

AU2023201549B1 - Device to prevent loss of liquid on high point vents

Info

Publication number: AU2023201549B1
Application number: AU2023201549A
Authority: AU
Inventors: David Nichols
Original assignee: Pipe Ex Pty Ltd
Current assignee: Pipe Ex Pty Ltd
Priority date: 2022-04-18
Filing date: 2023-03-14
Publication date: 2023-06-15
Anticipated expiration: 2043-03-14

Abstract

A vent valve assembly for use in venting excess gas or gas pressure, the vent valve assembly comprising: a housing defining a hollow central cavity with an in-use upper compartment separated from an in-use lower compartment by a diffuser plate; the lower compartment having an inlet orifice for receiving influent flow of fluid and the upper compartment comprising an outlet orifice for expulsion of the fluid; the diffuser plate being provided for allowing upward flow of fluid from the lower compartment to the upper compartment through the diffuser plate; an upper sealing ball retained in the upper compartment and prevented from passing through the diffuser plate into the lower compartment, wherein the upper sealing ball being movably disposed to move towards the outlet orifice and form a seal at or adjacent the outlet orifice to prevent expulsion of fluid through the outlet orifice.

Description

DEVICE TO PREVENT LOSS OF LIQUID ON HIGH POINT VENTS TECHNICAL FIELD

[001] The present invention relates generally to a device what is fitted to a High

Point Vent system for liquid pipe networks and, in particular but not exclusively, to a

Coal Seam Gas High Point Vent system to mitigate the loss of liquid should the High

Point Vent fail to operate correctly.

BACKGROUND

[002] Any references to methods, apparatus or documents of the prior art are not to

be taken as constituting any evidence or admission that they formed, or form part of

the common general knowledge.

[003] Coal Seam Gas (CSG) gathering systems commonly use high density

polyethylene (HDPE) pipe for gas and liquid flow lines. Gas and liquid is typically

extracted from multiple wells where gas and liquid is separated either "down hole" or

at the surface through a separator system. The gas and liquid is then distributed

through a gathering network, which is generally a complex infrastructure of

polyethylene (PE) pipelines, valves, fabricated risers and manifolds. Finally, the

network delivers gas to a gas compression station and liquid to a liquid pond or

treatment plant.

[004] Gathering networks can often have problems with plugging, where liquid

cannot pass through the network's pipes to gas locking at high points along the pipeline route. Efforts to avoid such problems include the installation of High Point

Vents, which are intended to remove, gas pockets at high point elevations on liquid

lines.

[005] The CSG industry often has issues with High Point Vents failing causing liquid

to be released to grade. This action is generally considered to be an environmental

pollutant relative to neighbouring properties, such as farmland, and thus the leakage

of such liquid onto neighbouring properties can be problematic. However, the failure

of High Point Vents can often lead to failed seals in the vents and the leakage of

liquid into the surrounding environment.

[006] FIG. 1 is a cross sectional view of a typical High Point Vent 100 according to

the prior art. The vent 100 includes a housing 105, a float 110, a vent valve 120, a

vent 125, a drain port 130 and inlet 115. The materials used in the construction of

the vent 100 are primarily metallic, and the design is subject to numerous operational

disadvantages. The disadvantages include corrosion of metallic parts, fouling or

blocking of the vent valve 115, a loss of function the vertical, thus leading to a loss of

liquid outlet 120 and 125.

[007] There is therefore a need for a device to stop the flow of liquid should the

High Point Vent mechanism fail open.

SUMMARY OF INVENTION

[008] In an aspect, the invention provides a vent valve assembly for use in venting

excess gas or gas pressure, the vent valve assembly comprising: a housing defining a hollow central cavity with an in-use upper compartment separated from an in-use lower compartment by a diffuser plate; the lower compartment having an inlet orifice for receiving influent flow of fluid and the upper compartment comprising an outlet orifice for expulsion of the fluid; the diffuser plate being provided for allowing upward flow of fluid from the lower compartment to the upper compartment through the diffuser plate; an upper sealing ball retained in the upper compartment and prevented from passing through the diffuser plate into the lower compartment, wherein the upper sealing ball being movably disposed to move towards the outlet orifice and form a seal at or adjacent the outlet orifice to prevent expulsion of fluid through the outlet orifice; wherein the in-use upper compartment further comprises a filter having a hollow structure with upstanding walls extending between a lower open end and an upper open end of the hollow structure wherein the upstanding walls comprise perforations for screening fluid and preventing solid particles from being received into an internal volume of the hollow structure.

[009] In an embodiment, the vent valve assembly further comprising a lower sealing

ball dimensioned to be retained within the lower compartment, the lower sealing ball

being movably disposed within the lower compartment to move towards the inlet and

orifice and form a seal adjacent the inlet orifice.

[0010]In an embodiment, the vent valve assembly further comprises a convergent

cross-section converging towards the inlet orifice.

[0011] Preferably, the hollow structure comprises a cylindrical cross section with the

upstanding walls extending between the upper and lower ends of the hollow

structure.

[0012]In an embodiment, an upper section of the upstanding walls adjacent the

upper end comprises said perforations and wherein a lower section adjacent the

lower end is impervious to fluids.

[0013]In an embodiment, the diffuser plate comprises an outer peripheral portion

with a plurality of openings to allow fluid to flow from the lower compartment to the

upper compartment.

[0014] In an embodiment, wherein the diffuser plate comprises a radially inner solid

portion that is impervious to fluids and solids wherein the inner solid portion is

adapted to receive the lower end of the hollow structure such that the lower section

of the hollow structure and the inner solid portion of the diffuser plate define a

collection chamber to collect fluid screened by the perforations of the cylindrical

structure.

[0015 In an embodiment, the inner solid portion of the diffuser plate comprises a

drain hole for draining liquid out of the collection chamber.

[0016] In an embodiment, a first section of the peripheral outer portion of the diffuser

plate comprises said plurality of openings and wherein a second section of the

peripheral outer portion is solid and impervious to flow of liquid.

[0017 In an embodiment, the inner solid portion comprises a guiding structure to

receive and guide the lower end of the hollow structure and seat the lower end of the

cylindrical structure along a sealing portion of the diffuser plate thereby forming a

seal between the inner solid portion of the diffuser plate and the lower end of the

cylindrical structure.

[0018 In an embodiment, the lower end of the hollow structure comprises a drain

hole that is preferably located adjacent the second section of the peripheral outer

portion of the diffuser plate.

[0019] In an embodiment, the vent valve assembly further comprises an alignment

mechanism to align the hollow structure of the filter for locating the drain hole

adjacent the second arcuate section in a fully engaged configuration.

[0020] In an embodiment, the diameter of the hollow structure is less than the overall

diameter of the upper compartment to define a void volume within the upper

compartment that surrounds the upstanding walls of the filter for receiving fluid from

the lower compartment through the openings provided in the peripheral region of the

diffuser plate.

[0021 In an embodiment, the upper sealing ball is substantially buoyant in liquid,

preferably water and substantially non-buoyant in gas.

[0022] In an embodiment, the upper compartment comprises one or more draining

ports for draining fluid out of the upper compartment.

[0023 In an embodiment, the vent valve assembly further comprises a pressure

monitoring device positioned within the housing to measure pressure within the

internal volume of the upper and lower compartments.

[0024] In an embodiment, the upper compartment further comprises an upper section

that is removably attached to a lower section.

[0025] In an embodiment, the upper section comprises the outlet orifice and wherein

the lower section comprises the draining outlet.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026]To assist in understanding the invention and to enable a person skilled in the

art to put the invention into practical effect, preferred embodiments of the invention

are described below by way of example only with reference to the accompanying

drawings, in which:

FIG. 1 is a cross sectional view of a typical Gas High Point Vent according to the

prior art.

FIG. 2 is a sectional isolated view for an upper section of the upper compartment for

a vent valve assembly 600.

FIG. 3 is a side view of the lower section of the upper compartment and the lower

compartment for the vent valve assembly 600.

FIG 4. Is an isolated view of the hollow cylindrical structure 400 and the upper

sealing ball 420.

FIG. 5 is a side view of the diffuser plate assembly 500.

FIG. 5a is an exploded sectional view of the diffuser plate assembly 500.

FIG. 6 is a sectional view of the vent valve assembly 600.

FIG. 7 is an exploded view of the vent valve assembly 600.

FIG 8 is an exploded perspective view of the vent valve assembly 600.

FIG 9 is a top perspective view of the vent valve assembly 600.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0027] The present invention relates to a device to prevent loss of liquid. Elements of

the invention are illustrated in concise outline form in the drawings, showing only

those specific details that are necessary to understanding the embodiments of the

present invention, but so as not to clutter the disclosure with excessive detail that will

be obvious to those of ordinary skill in the art in light of the present description.

[0041] In this patent specification, adjectives such as first and second, inside and

outside, above and below, longitudinally and transverse, top and bottom, upper and lower, rear, front and side, etc., are used solely to define one element or method step from another element or method step without necessarily requiring a specific relative position or sequence that is described by the adjectives. Words such as

"comprises" or "includes" are not used to define an exclusive set of elements or

method steps. Rather, such words merely define a minimum set of elements or

method steps included in a particular embodiment of the present invention.

[0028]Referring to Figures 6 to 9, a high point vent valve assembly 600 has been

illustrated. The valve assembly 600 described herein is particularly useful for

overcoming loss of liquid during operations. The valve assembly 600 provides a

mechanical system which is capable of working in varied gas and liquid flow

conditions whilst still avoid expulsion of liquid phase pollutants from the valve

assembly 600.

[0029] The valve assembly 600 comprises a housing that defines an elongate hollow

cavity that is split into an upper compartment and a lower compartment. The upper

compartment is formed by an upper compartment housing 200 which is separated

from a lower compartment housing 300 with a diffuser plate 500 separating the

upper and lower compartments.

[0030]As shown best in Figures 2 and 3, the upper compartment housing 200

comprises an upper section 220 and a lower section 250 which can be threadably

engaged with each other through threads 215 which engage with threads 230

provided on the lower section 250 of the upper compartment 200. The upper section

220 comprises an outlet orifice 205 for expulsion of gas. Effectively, the outlet orifice

205 forms the high vent for the vent valve assembly 600. Referring to Figure 3, the

lower section 250 of the upper compartment 200 is integrally formed with the lower

compartment housing 300. The reasons for integrally forming the lower section 250

with the lower compartment housing 300 will be explained in the foregoing sections.

The lower compartment housing 300 comprises an inlet orifice 310 that allows fluid

(including liquid and gas mixtures) into the hollow cavity of the lower compartment

housing 300.

[0031]Referring to Figures 5, 5a and 6, the diffuser plate assembly 500 generally

comprises a disc-shaped diffuser member 505. The diffuser member 505 comprises

a peripheral or circumferential outer region with pass through holes 510 being

provided along a portion of the circumferential region for allowing fluid (liquid and

gas) to pass through from the hollow cavity of the lower compartment 300 into the

hollow cavity of the upper compartment 200. The diffuser plate 505 also includes a

radially inner solid portion 502. A first arcuate section of the outer region comprises

the pass through holes 510 and a second arcuate section of the outer region is solid

and impervious to flow of liquid.

[0032]The upper compartment 200 also comprises a filter assembly 400. The filter

assembly 400 comprises a hollow cylindrical structure 402 with upstanding walls

extending between a lower open end and an upper open end . The lower open end

for the cylindrical structure 402 is adapted to be seated on the diffuser assembly 500

to form a seal using O-ring 530 such that the inner solid portion 502 of the diffuser

plate assembly becomes enclosed by the lower section of the cylindrical structure

402. As a result, the lower section of the cylindrical structure 402 when sealed with the inner solid portion 502 defines a collection chamber for collecting liquid during use. Referring to Figure 6, when a liquid and gas mixture is received into the lower compartment housing 300 under pressure, the passthrough holes 510 allow that liquid and gas mixture to be received into the void volume defined by inner walls of the upper compartment housing 200 and the outer walls of the cylindrical structure

402. The upper section or region of the cylindrical structure 402 forms a screen for

screening solid particles from entering the internal volume of the cylindrical structure

402. Specifically, the screened liquid gas mixture is collected in the collection

chamber formed by the filter assembly 400 when assembled with the diffuser

assembly 500.

[0033]An upper sealing ball 420 is located within the collection chamber and as the

screened liquid starts collecting in the collection chamber, the upper sealing ball 420

starts rising with the liquid. It would be understood that the upper sealing ball 420 is

buoyant in the liquid which results in the upward movement of the upper sealing ball

420 towards the vent outlet 205 to ultimately engage sealing portion 210 to form a

seal against the vent outlet 205 and prevent the expulsion of liquid from the vent

outlet 205.

[0034] The closure of the outlet orifice 205 results in a rise in hydrostatic pressure

within the upper compartment resulting in flow and accumulation of liquid in the lower

compartment housing 300. The lower compartment 300 is also provided with a lower

sealing ball 535 which is retained with the cavity of the lower compartment housing

300. The lower compartment housing 300 comprises a downwardly convergent inner

section which converges towards the inlet orifice 310. The convergent configuration of the inner section is adapted to engage with the lower sealing ball 535 to form a lower seal which prevents ingress of air through the inlet 305 should the seal formed on the outlet orifice 205 fail and vacuum is present in the system.

[0035] Advantageously, a pressure monitoring device 320 can be provided to

measure pressure levels within the housing (upper or lower compartment). A drain

outlet may also provided for draining liquid out of the compartment if and when

pressure increases. A drain hole 415 is also provided in the inner solid portion 502

for draining liquid out of the collection chamber (formed by the filter assembly 400

and the diffuser plate assembly 500) into the lower housing cavity. The lower section

of the cylindrical structure comprises a drain hole that is preferably positioned

adjacent the second arcuate section of the outer peripheral portion of the diffuser

assembly 500. Any suitable alignment mechanism including visual indicators may be

provided on the diffuser assembly 500 and/or the cylindrical structure 402 for

aligning the drain hole 415 in this manner. The alignment of the drain hole 415 in this

manner prevents air from entering through the drain hole 415 and spinning or

pushing the upper sealing ball 420 towards the vent outlet 205.

[0036]When the upper and lower sealing balls 420 and 535 move into their

respective sealing configurations in a manner as described above, the internal

volume of the housing becomes pressurised resulting in a pressurised valve device.

Therefore, a pressure relief valve 325 is provided to relieve the hydrostatic pressure

within the device. The pressure relief valve 325 may also allow draining of liquid out

of the device to reduce hydrostatic pressure within the housing of the valve assembly

600.

[0037] There are several advantages provided by the improved valve assembly 600.

First of all, any solid particles which are typically found in liquid gas mixtures

extracted from CSG wells are screened by the filter assembly 400 and accumulate

within the void formed between the inner walls of the upper compartment housing

200 and the outer walls of the cylindrical structure 402 of the filter assembly. The

threadable engagement between the upper section 220 of the upper compartment

200 with the lower section 250 facilitates easy removal of the filter assembly 400 and

cleaning of the internal volume defined by upper compartment housing 200.

[0038] In compliance with the statute, the invention has been described in language

more or less specific to structural or methodical features. The term "comprises" and

its variations, such as "comprising" and "comprised of" is used throughout in an

inclusive sense and not to the exclusion of any additional features.

[0039 It is to be 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.

[0040] The invention is, therefore, claimed in any of its forms or modifications within

the proper scope of the appended claims appropriately interpreted by those skilled in

the art.

Claims

1. A vent valve assembly for use in venting excess gas or gas pressure, the vent

valve assembly comprising:

a housing defining a hollow central cavity with an in-use upper compartment

separated from an in-use lower compartment by a diffuser plate;

the lower compartment having an inlet orifice for receiving influent flow of fluid

and the upper compartment comprising an outlet orifice for expulsion of the fluid;

the diffuser plate being provided for allowing upward flow of fluid from the

lower compartment to the upper compartment through the diffuser plate;

an upper sealing ball retained in the upper compartment and prevented from

passing through the diffuser plate into the lower compartment,

wherein the upper sealing ball is movably disposed to move towards the outlet orifice

and form a seal at or adjacent the outlet orifice to prevent expulsion of fluid through

the outlet orifice;

wherein the in-use upper compartment further comprises a filter having a hollow

structure with upstanding walls extending between a lower open end and an upper

open end of the hollow structure wherein the upstanding walls comprise perforations

for screening fluid and preventing solid particles from being received into an internal

volume of the hollow structure;

2. A vent valve assembly in accordance with claim 1 further comprising a lower

sealing ball dimensioned to be retained within the lower compartment, the lower sealing ball being movably disposed within the lower compartment to move towards the inlet and orifice and form a seal adjacent the inlet orifice.

3. A vent valve assembly in accordance with claim 1 or claim 2 further

comprising a convergent cross-section converging towards the inlet orifice.

4. A vent valve assembly in accordance with any one of the preceding claims

wherein the hollow structure comprises a cylindrical cross section.

5. A vent valve assembly in accordance with any one of the preceding claims

wherein an upper section of the upstanding walls adjacent the upper end comprises

said perforations and wherein a lower section adjacent the lower end is impervious

to fluids.

6. A vent valve assembly in accordance with any one of the claims wherein the

diffuser plate comprises an outer peripheral portion with a plurality of openings to

allow fluid to flow from the lower compartment to the upper compartment.

7. A vent valve assembly in accordance with claim 6 wherein the diffuser plate

comprises a radially inner solid portion that is impervious to fluids and solids wherein

the inner solid portion is adapted to receive the lower end of the hollow structure

such that the lower section of the hollow structure and the inner solid portion of the diffuser plate define a collection chamber to collect fluid screened by the perforations of the cylindrical structure.

8. A vent valve assembly in accordance with claim 7 wherein the inner solid

portion of the diffuser plate comprises a drain hole for draining liquid out of the

collection chamber.

9. A vent valve assembly in accordance with claim 6 wherein a first section of

the peripheral outer portion of the diffuser plate comprises said plurality of openings

and wherein a second section of the peripheral outer portion is solid and impervious

to flow of liquid.

10. A vent valve assembly in accordance with any one of claims 7 to 9 wherein

the inner solid portion comprises a guiding structure to receive and guide the lower

end of the hollow structure and seat the lower end of the cylindrical structure along a

sealing portion of the diffuser plate thereby forming a seal between the inner solid

portion of the diffuser plate and the lower end of the cylindrical structure.

11. A vent valve assembly in accordance with claim 10 when dependent on claim

9 wherein the lower end of the hollow structure comprises a drain hole that is

preferably located adjacent the second section of the peripheral outer portion of the

diffuser plate.

12. A vent valve assembly in accordance with claim 11 further comprising an

alignment mechanism to align the hollow structure of the filter for locating the drain

hole adjacent the second arcuate section in a fully engaged configuration.

13. A vent valve assembly in accordance with any one of the preceding claims

wherein the diameter of the hollow structure is less than the overall diameter of the

upper compartment to define a void volume within the upper compartment that

surrounds the upstanding walls of the filter for receiving fluid from the lower

compartment through the openings provided in the peripheral region of the diffuser

plate.

14. A vent valve assembly in accordance with any one of the preceding claims

wherein the upper sealing ball is substantially buoyant in liquid, preferably water and

substantially non-buoyant in gas.

15. A vent valve assembly in accordance with any one of the preceding claims

wherein the upper compartment comprises one or more draining ports for draining

fluid out of the upper compartment.

16. A vent valve assembly in accordance with any one of the preceding claims

further comprising a pressure monitoring device positioned within the housing to

measure pressure within the internal volume of the upper and lower compartments.

17. A vent valve assembly in accordance with any one of the preceding claims

wherein the upper compartment further comprises an upper section that is

removably attached to a lower section.

18. A vent valve assembly in accordance with claim 17 wherein the upper section

comprises the outlet orifice and wherein the lower section comprises the draining

outlet.

250 220

300

Fig 5a 2023201549

525

520 500

505 510

512 525 520 500

505 512 510

220 400

300

Fig 7 205 2023201549

Fig 7 220 405

600 400

415 420

535 500

250

300

Fig 8 200 2023201549

Fig 9

400 600

600 420

500

535