GB2398856A

GB2398856A - A rotary disc valve

Info

Publication number: GB2398856A
Application number: GB0304382A
Authority: GB
Inventors: David Griffin; Ed Wallis; Chris Williamson
Original assignee: BRITISH ENGINES Ltd
Current assignee: BRITISH ENGINES Ltd
Priority date: 2003-02-28
Filing date: 2003-02-28
Publication date: 2004-09-01
Anticipated expiration: 2023-02-28
Also published as: GB0304382D0; GB2398856B

Abstract

A rotary gate valve 10 comprising a body 32 and a gate 18 rotatably mounted in the body 32, the body 32 having an inlet port 42, an outlet port 44 and a bleed port (54, figure 4), the gate 18 having an inlet aperture 34, an outlet aperture 36 and a reservoir 37 therebetween, wherein the gate 18 is rotatable between a first position wherein the inlet port 42, the outlet port 44, the inlet aperture 34 and the outlet aperture 36 are aligned so as to provide a fluid communication path through the valve 10, and a second position wherein the inlet port 42, outlet port 44, inlet aperture 34 and outlet aperture 36 are no longer aligned so as to close the fluid communication path, wherein further in said second position the bleed port (54, figure 4) is in fluid communication with the reservoir 57. The inlet port 42 and outlet port 44 may be provided on the same side of the gate 18. In said second position of the gate 18 the bleed port (54, figure 4) may be in fluid communication with the reservoir 57 through one of said gate inlet aperture 34 and said gate outlet aperture 36. The reservoir 57 may be a hollow in the body of gate 18 in the form of a circular recess on the surface of the gate 18.

Description

1 2398856 Improved Rotary Disc Valve The present invention relates to a

disc valve, and in particular to a block and bleed rotary disc valve.

It is known to provide three disc valves in series along a fluid pipe. An arrangement of valves so described can be used to bleed an unwanted fluid in the pipe by closing the valves at the end of the series and opening the valve in the middle of the series so that any unwanted fluid between the end valves can be vented.

One of the main disadvantages of such a series of prior art disc valves is that to perform a bleeding operation requires three valves. In cases where the fluid in the pipe is under very high pressure the valves are required to be of very high complexity and quality which consequently produces a very high cost for such an arrangement of valves. The cost of each valve is considerably higher where the valve is required to operate in extreme environments such as on the seabed.

What is required is an improved disc valve to permit bleeding of a pipe to which it is connected.

According to the invention there is provided a rotary disc valve, the valve having a body and a gate rotatably mounted in the body, the body having an inlet port, an outlet port and a bleed port, the gate having an inlet aperture, an outlet aperture and a reservoir therebetween, wherein the gate is rotatable between a first position wherein the inlet port, the outlet port, the inlet aperture and the outlet aperture are aligned so as to provide a fluid communication path through the valve, and a second position wherein the inlet port, outlet port, inlet aperture and outlet aperture are no longer aligned so as to close the fluid communication path, the bleed port being in fluid communication with the reservoir.

A rotary disc valve so arranged eliminates the requirement to provide three valves for a bleeding operation since the reservoir can be vented to the bleed port whilst the inlet port and outlet port are not in fluid communication.

In a preferred embodiment the inlet port and outlet port are on the same side of the gate.

This arrangement permits fluid to enter the inlet port on one side of the gate. pass through the gate and then exit the outlet port on the same side of the gate.

The reservoir may be a hollow within the body of the gate. Alternatively the reservoir may be defined by a recess on a surface of the gate. In such an embodiment the recess may be semicircular in cross-section.

The recess may be circular in plan, with the inlet aperture and the outlet aperture are diametrically opposed about the recess. The bleed aperture may be positioned perpendicularly in the body in plan with respect to the inlet aperture and the outlet aperture.

Preferably the gate is a disc shape and the body is constructed from a base and a cap.

the gate being located in a recess of the cap. This provides a convenient means for constructing the valve so that the gate can be easily located in the body.

Preferably each inlet port and outlet port is provided with a respective seat which is movably mounted in the base. In a preferred embodiment each seat is cylindrical having a channel therethrough, the seat being located in a corresponding cylindrical recess in the base. Each seat is sealed to the base by an O-ring around the circumference of the seat to permit axial movement of the seat in the cylindrical recess, wherein fluid under pressure within the inlet and outlet ports act to move the seat against the gate to provide a seal therebetween.

Preferably a resilient C-ring is provided between each seat and the base so that when the fluid in the inlet port and the outlet pOl1 iS not under pressure a seal is still maintained between the respective seat and the gate.

Other features of the invention will be apparent from the following description of a preferred embodiment shown by way of example only in the accompanying drawings, in which: Figure 1 is a perspective view of a disc valve assembly according to the present invention; Figure 2 is a diagrammatic representation of a detail of a seal carrier of Figure 1; Figure 3 is a diagrammatic representation of a detail along section V-V of the assembly of Figure 1; Figure 4 is a plan view of the body of the valve in Figure 1; Figure 5 is a diagrammatic representation of a detail along section Z-Z of the body of Figure 4; and, Figure 6 is a plan view of the gate of the valve in Figure 1.

Referring firstly to Figure I there is shown a disc valve assembly in accordance with the present invention. generally designated 10. The assembly 10 comprises a docking cylinder 12 that is connected to a drive shaft 14. The drive shaft 14 is rotationally coupled to a stem 16 that, in turn, is operable to rotate a disc shaped gate 18. The drive shaft 14, stem 16 and gate 18 are housed in, and extend through, an assembly comprising a bearing housing 20, a bonnet 26 and a body 32. The bonnet 26 and the body 32 form together substantially the shape of a cube. The bearing housing forming substantially the shape of a cylinder mounted on the cube. A fluid tight seal is provided between the drive shaft 14 and the bearing housing 20 by the provision of seals 22 and 24. The stem 16 and gate 18 are housed in the bonnet 26, the housing 20 and bonnet 26 being fastened together by fixings 28. A seal carrier 30 is disposed between the bonnet 26, the housing 20 and the stem 16.

The gate 18 of Figure I is rotatably mounted between the bonnet 26 and a body 32. The bonnet 26 and body 32 are fastened together by fixings (not shown). The gate has two spaced apart channels 34, 36 that are in fluid communication with each other via a circular recess 37 having a semicircular cross section. Each channel 34, 36 is in fluid communication with an axial passage in a respective cylindrical seat ring 38, 40. The seat rings 38, 40 are movably mounted in recesses of the body 32. The body 32 has two apertures 42, 44 in fluid communication with a respective seat ring 38. 40. Each seat ring 38, 40 is sealed to the body 32 by a respective O-ring 39 41. Each seat 38, 40 has a metal C-ring 43, 45 disposed between each seat ring 38, 40 and the body 32. s

Referring now to Figure 2 there is shown a diagrammatic representation of a detail of the seal carrier 30 of Figure 1. In Figure 2 the carrier 30 has an internal seal 46 to seal the carrier 30 to the stem 16, and an external seal 48 to seal the carrier 30 and bonnet 26. A base seal 50 is also provided to act as a further seal between the carrier 30, the bonnet 76 and the stem 16.

Referring now to Figure 3 there is shown a diagrammatic representation of a detail along section V-V of the assembly of Figure 1. In Figure 3 there are shown fasteners 52 which fasten the seal carrier 30 to the bonnet 26.

In Figure 4 there is shown a plan view of the body 32 of the valve assembly 10 shown in Figure 1. The two apertures 42, 44 and their respective seat rings 38, 40 are shown.

A bleed aperture 54 is also shown which has a inlet 56. the bleed aperture 54 being perpendicularly arranged in plan view between the apertures 42, 44. In use the fluid required to be bled from the recess 37 may enter the inlet 56 under gravity or may be forced into the inlet 56 under residual pressure within the recess 37. Figure 5 shows a diagrammatic representation of a detail along section Z-Z of the body 32 of Figure 4.

The section Z-Z illustrates the bleed aperture 54 in fluid communication with its respective inlet 56. Figure 5 shows that the bleed aperture 54 and its inlet 56 are arranged perpendicularly to one another.

Referring now to Figure 6 there is shown a plan vie\\ of the gate 18 of the valve assembly 10 shown Figure 1. The two spaced apart chamlels 34 36 of the gate 18 are illustrated together with the circular recess 37 \\hicl1 permits fluid communication between the channels 34, 36.

In use, the disc valve assembly 10 is operable to block and bleed a fluid line. The valve assembly 10 permits a fluid supply through the line to be stopped and then bled to remove unwanted fluids from the line. In use the valve is normally open whereby fluid such as gas flows into the aperture 42, through the seat ring 38, into the channel 34, through the circular recess 37, through the channel 36, through the seat ring 40 and out through the aperture 44. In operation an arm (not shown) of an underwater vehicle (not shown) is coupled to the drive shaft 14. The arm rotates the drive shaft 14 which rotates the gate 18 so that the aperture 34 and axial passage in the seating ring 38 and the aperture 36 and axial passage in the seating ring 40 are not aligned. This closes the fluid communication path through the assembly 10. As the gate 18 is further rotated to 90 from the initial position, one of the channels 34, 36 moves over the inlet 56 to the bleed aperture 54. Any fluid in the circular recess 37 is thus able pass into the bleed port 37 under gravity or under residual pressure in the recess 37.

IS Fluid under pressure in the closed off apertures 42, 44 pushes the seat rings 38, 40 against the gate 18 due to the O-rings 39, 41 to form a metal to metal seal between each seat ring 38, 40 and the base of the gate 18. Under low pressure of the fluid the metal C-rings 43, 45 act to push the seat rings 38, 40 against the gate 18. The valve assembly can be used to bleed air from an oil supply or water from a gas supply.

The valve assembly 10 can also be utilised with only one of apertures 42, 44 under pressure. In this instance only one of the seat rings 38, 40 acts to form a metal to metal seal, the other seat ring being redundant.

A prior art disc valve typically has an inlet and an outlet which are in line with one another. A rotary disc having a hole therethrough is provided between the inlet and the outlet. Upon alignment of the hole with the inlet and the outlet, fluid is permitted to pass through the valve. It will be appreciated that this arrangement differs substantially from the rotary disc valve 10 of the present invention whereby the valve 10 permits fluid to flow in a circular recess on the surface of the disc.

Claims

Claims 1. A rotary gate valve, the valve having a body and a gate

rotatably mounted in the body. the body having an inlet port, an outlet port and a bleed port, the gate having an inlet aperture, an outlet aperture and a reservoir therebetween, wherein the gate is rotatable between a first position wherein the inlet port, the outlet port, the inlet aperture and the outlet aperture are aligned so as to provide a fluid communication path through the valve, and a second position wherein the inlet port, outlet port, inlet aperture and outlet aperture are no longer aligned so as to close the fluid communication path, wherein further in said second position the bleed port is in fluid communication with the reservoir.
2. A rotary gate valve as claimed in claim I wherein the inlet port and outlet port are provided on the same side of the gate.
3. A rotary gate valve as claimed in claim I or claim 2 wherein in said second position of the gate said bleed port is in fluid communication with the reservoir through one of said gate inlet aperture and said gate outlet aperture.
4. A rotary gate valve as claimed in any preceding claim wherein the reservoir comprises a hollow within the body of the gate.
5. A rotary gate valve as claimed in claim 4 wherein the reservoir is a recess on a surface of the gate.
6. A rotary gate valve as claimed in claim 5 wherein the recess is circular.
7. A rotary gate valve as claimed in claim 6 \\herein the inlet and outlet apertures are diametrically opposed about the recess.
8. A rotary gate valve as claimed in any preceding claim wherein the inlet and outlet ports are provided with respective seats which are movably mounted in the base.
9. A rotary gate valve as claimed in claim 8 wherein said seats are movable under fluid pressure to bear against the gate.
10. A rotary gate valve as claimed in claim 8 or claim 9 and including a biasing member disposed between each of said seats and said gate.