GB2365949A

GB2365949A - Ball valve

Info

Publication number: GB2365949A
Application number: GB0020248A
Authority: GB
Inventors: Steven Nicholls
Original assignee: SV SYSTEMS Ltd
Current assignee: SV SYSTEMS Ltd
Priority date: 2000-08-17
Filing date: 2000-08-17
Publication date: 2002-02-27
Anticipated expiration: 2020-08-17
Also published as: GB2365949B; GB0020248D0

Abstract

A valve (1) comprises a housing (2) having an inlet (3) and an outlet (4). The housing (2) defines an internal valve chamber (16) between the inlet (3) and the outlet (4), in which a composite valve element (12) having a through bore (14) is snugly but rotatably located. The composite valve element (12) may be rotated from a first, open position in which the through bore (14) is aligned with the inlet (3) and the outlet (4) so as to define a flowpath therebetween to a second, closed position in which the through bore (14) is aligned with neither the inlet (3) nor the outlet (4) and in which a surface of the composite valve element (12) serves to seal the inlet (3) and the outlet (4) where these open into the valve chamber (16). Both the composite valve element (12) and the housing (2) are separable into at least first and second respective parts (19, 19'; 8, 8') when the valve (1) is in the closed position such that the first part (19) of the composite valve element (12) remains in a sealing relationship with the first part (8) of the housing (2) and the second part (19') of the composite valve element (12) remains in a sealing relationship with the second part (8') of the housing (2) when the first and second parts (19, 19'; 8, 8') of both the composite valve element (12) and the housing (2) are separated from each other. The valve (1) may therefore be separated into two parts when in the closed position, each part sealing either the inlet (3) or the outlet (4).

Description

<Desc/Clms Page number 1> IMPROVED BALL VALVE The present invention relates to a ball valve.

Ball valves are commonly used in fluid supply lines, both in large-scale industrial plant as well as in domestic applications such as bathroom taps, A ball valve generally comprises a housing having a fluid inlet on one side and a fluid outlet on an opposed side, the housing defining a valve chamber adapted to receive a one-piece generally spherical or part-spherical valve element (generally known as a ball). The ball is rotatable within the valve chamber and is provided with a through bore. To set the ball valve in an open position, the ball is rotated to a position where the fluid inlet, the bore and the fluid outlet are all aligned so as to define a fluid passage through the ball valve as a whole. By rotating the ball from this position, it is possible progressively to close the ball valve until the bore no longer communicates with the fluid inlet or outlet, thereby preventing fluid flow through the valve as a whole.

According to the present invention, there is provided a valve comprising a housing having an inlet and an outlet and an internal valve chamber between the inlet and the outlet, a composite valve element snugly located within the valve chamber and having a through bore, the composite valve element being rotatable within the valve chamber from a first, open position in which the through bore is aligned with the inlet and the outlet so as to define a flowpath therebetween to a second, closed position in which the through bore is aligned with neither the inlet nor the outlet and in which a surface of the composite valve element serves to seal the inlet and the outlet where these open into the valve chamber, wherein both the composite valve element and the housing are separable into at least first and second respective parts when the valve is in the closed position such that the first part of the composite valve element remains in a sealing relationship with the first part of the housing and the second part of the composite valve element remains in a sealing relationship with the

second part of the housing when the first and second parts of both the composite valve element and the housing are separated from each other.

I In this way, it is possible to isolate the inlet and the outlet sides of the valve from each other and then to separate the valve into two parts, even when there is pressure or vacuum at either the inlet or the outlet or both sides of the valve. Where the valve is installed in a feed line to, say, an inlet of a reactor chamber in a chemical plant, the feed line and the inlet of the reactor chamber can be isolated and the valve separated into two parts without the need to close either the feed line further upstream from the valve or the inlet of the reactor chamber further downstream from the valve. A second feed line having a corresponding part valve may then be connected to the part valve on the reactor chamber inlet in place of the first feed line and part valve.

Advantageously, the composite valve element in its assembled form includes a portion which is substantially spherical or at least substantially part- spheri ca 1, for example having a shape which corresponds substantially to a spherewhich has had at least one segment removed, and more preferably has had two generally diametrically opposed segments removed. The composite valve element may be made out of a metal such as stainless steel and/or HastelloyCR, or the like or, in some applications, out of a plastics material or any other suitable material.

The composite valve element is preferably provided with a pair of trunnions arranged in diametrical opposition on either side of the aforementioned spherical or part- spherical portion. The trunnions are preferably cast or Moulded as one piece with the composite valve element, each of the first and second parts of the composite valve element being provided with a trunnion. The housing is provided with corresponding sleeves into which the trunnions fit snugly and rotatably, one sleeve being Provided in each of the first and second parts of the housing, such that the composite valve element may be rotated between closed and open positions, for example by way of a handle which is connected to one or other of the trunnions and which is mounted on the outside of the housing.

In a preferred embodiment, the trunnions are longitudinally disposed along a first axis which passes through a centre of the spherical or part-spherical portion of the valve element, and the through bore is longitudinally disposed along a second axis which is substantially perpendicular to the first axis and which also passes through the centre of the portion of the valve element. In this prefer-red embodiment, the valve element is divided in two along a plane which substantially includes the second axis, thus bisecting the through bore along its length, and through which the first axis passes at an angle of between 0' and 90", preferably from 10' to 80', more preferably from 20' to 70' and even more preferably from 30' to 60'. The two parts of the composite valve element may be releasably secured together by way of dowels or the like. The housing is correspondingly divided into two parts along a plane of division which coincides with the aforementioned plane when the composite valve element has been rotated into its fully-closed position, the inlet being located in a first part and the outlet in a second part. The inlet and outlet are preferably longitudinally disposed along a third axis which passes through the centre of the portion of the composite valve element and which substantially coincides with the second axis when the composite valve element has been rotated into its fully-open position, A flange is preferably provided on each part of the housing so as to define a pair of mating surfaces aligned with the plane of division which can be held tightly together by way of clips or an annular sealing member (e.g. a sealing ring) or the like.

A valve seat is preferably provided where each of the inlet and the outlet where these open into the valve chamber. The valve seats may each take the form of a ring of suitable material which is substantially centred about the third axis and mounted in the wall of the valve chamber so as to contact the portion of the composite valve element in a sealing relationship when the valve is in its assembled condition. The valve seats may be made out of energised polytetrafluoroethylene (PTFE), polyvinylidenefluoride (PVDF) or other suitable materials.

The trunnions are preferably retained within the sleeves of the housing by way of bolts or the like located along and aligned with the first axis, thus allowing the composite valve element to rotate about the first axis while each part of the composite valve element is respectively constrained from lateral movement relative to each part of the housing. By constraining the parts of the composite valve element in this way, improved sealing, of the inlet and outlet is achieved when the valve is in its separated condition, thereby allowing the valve to be used in pressure and/or vacuum containment transfers.

For a better understanding of the present invention and to show how it may be carried into effect, reference shall now be made by way of example to the accompanying drawings, in which: FIGURE I shows a front elevation of a valve of the present invention; FIGURE 2 shows a vertical cross section through the valve of Figure I - and FIGUR,E 3 shows a vertical cross section thrOLI()h the valve of Figure I in a separated lz# condition.

Referring firstly to Figure 1, there is shown a valve I comprising a housing 2 having an inlet 3 and an outlet 4. A central portion of the housing 2 is provided with a pair of sleeves 5, 5# which serve to locate a pair of trunnions (not shown in Figure 1) which forni part of a composite valve element (not shown in Figure 1) which is located within the housing 2. One of the trunnions is provided with a handle 7 by means of which the composite valve element may be rotated within the housing 2. The housing 2 is divided into separable Lipper and lower housing components 8, 8' along an inclined plane X-X which passes through the central portion of the housing 2, each housing component 8, 8' being provided with a flange 9, 9' about its facing surface. The flanoes 9, 9# are releasably held together by a sealing ring 10 (shown in Figure 2). In use, a fluid supply line (not shown) is connected to the inlet 3 and a

fluid output line (not shown) is connected to the outlet 4, and the valve 1 may then be used to control the flow of fluid from the supply line to the output line.

Figure 2 shows the valve 1 of Figure I in vertical cross section. A composite valve element 12 is located between the inlet 3 and outlet 4 in the central portion of the housing 2. The composite valve element 12 has a substantially spherical central portion 13 having a bore 14 formed centrally therethrough, and a pair of trunnions 15, 15', one on either side of the central portion 13 and snugly but rotatably located within the sleeves 5, 5'. Each trunnion 15, 15' is retained within its sleeve 5, 5' and constrained from reciprocal movement therein by a bolt 18, 18'. The central portion 13 of the composite valve element 12 is snugly and rotatably mounted within an inner chamber 16 of the housing 2, and the handle 7 is attached to the trunnion 5' so as to enable the composite valve element 12 to be rotated within the housing 2. Annular valve seats 17, 17' are provided where each of the inlet 3 and outlet 4 enter the inner chamber 16. The composite valve element 12 is formed as two parts 19, 19', these parts interfacing with each other along a plane Y-Y which passes through the central portion 13 of the composite valve element 12. The two parts 19, 19' of the composite valve element 12 are releasably secured together at their facing surfaces by way of dowels 20. In Figure 2, the composite valve element 12 is shown in its closed position, i.e. with the central portion 13 rotated such that the bore 14 is substantially perpendicular to a line connecting the inlet 3 and the outlet 4, both of these being sealed from each other by the central portion 13 of the composite valve element 12 which rests against the annular valve seats 17, 17'. It is apparent from Figure 2 how the composite valve element 12 may be rotated by way of the handle 7 so that the bore 14 through the central portion 13 is progressively moved into line with the inlet 3 and the outlet 4, thereby allowing fluid flow from the inlet 3 to the outlet 4. Further apparent from Figure 2, and shown explicitly in Figure 3, is that when the composite valve element 12 is in its closed position, as shown, the plane Y-Y along

which the composite valve element 12 is divided into its two parts 19, 19' is coincident with the plane X-X along which the housing 2 is divided into its upper and lower housing components 8, 8'. By removing the sealing ring 10, the upper housing component 8 and its associated part 19 of the composite valve element 12 may be separated from the lower housing component 8' and its associated part 19' of the composite valve element 12 along the line of the coincident planes X-X and Y-Y as shown in Figure 3. Each part 19, 19' remains in a sealing relationship with its associated valve seat 17, 17', thereby keeping the inlet 3 and the outlet 4 closed to fluid flow. The parts 19, 19' are held in place by way of their associated trunnions 15, 15' being rotatably secured within the sleeves 5, 5'.

Claims

CLAIMS: 1. A valve comprising a housing having an inlet and an outlet and an internal valve chamber between the inlet and the outlet, a composite valve element snugly located within the valve chamber and having a through bore, the composite valve element being rotatable within the valve chamber from a first, open position in which the through bore is aligned with the inlet and the outlet so as to define a flowpath therebetween to a second, closed position in which the through bore is aligned with neither the inlet nor the outlet and in which a surface of the composite valve element serves to seal the inlet and the outlet where these open into the valve chamber, wherein both the composite valve element and the housing are separable into at least first and second respective parts when the valve is in the closed position such that the first part of the composite valve element remains in a sealing relationship with the first part of the housing and the second part of the composite valve element remains in a sealing relationship with the second part of the housing when the first and second parts of both the composite valve element and the housing are separated from each other.
2. A valve as claimed in claim 1, wherein the composite valve element in its assembled form includes a portion which is substantially spherical in form.
3. A valve as claimed in claim 1, wherein the composite valve element in its assembled form includes a portion which is substantially part-spherical in form.
4. A valve as claimed in claim 2 or 3, wherein the composite valve element further includes a pair of trunnions disposed on either side of the substantially spherical or part spherical portion.
5. A valve as claimed in claim 4, wherein each of the first and second parts of the composite valve element is provided with a trunnion.

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6. A valve as claimed in claim 4 or 5, wherein the trunnions are cast or moulded as one piece with the composite valve element or part thereof 1
7. A valve as claimed in one of claims 4 to 6, wherein the housing is provided with a pair of sleeves, one in each of the first and second parts of the housing, which are adapted to receive the trunnions and to allow the composite valve element to rotate within the housing.
8. A valve as claimed in any one of claims 5 to 7, wherein at least one of the trunnions is provided with a handle which is accessible from outside the housing and which enables the composite valve element to be rotated within the housing,
9. A valve as claimed in any one of claims 5 to 8, wherein the trunnions are longitudinally disposed along a first axis which passes through a centre of the substantially spherical or part-spherical portion of the composite valve element when the valve is in its assembled condition, and wherein the through bore is longitudinally disposed along a second axis which is substantially perpendicular to the first axis and which also passes through the centre of the portion of the composite valve element.
10. A valve as claimed in claim 9, wherein the composite valve element is divided into its first and second parts along a first plane which substantially includes the second axis, thus bisecting the through bore along its length, and through which the first axis passes at an angle of between 0' and 90'.
11. A valve as claimed in claim 10, wherein the first axis passes through the plane at an angle from 100 to 8 00,
12. A valve as claimed in claim 10, wherein the first axis passes through the plane at an angle from 20" to 700.

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13. A valve as claimed in claim 10, wherein the first axis passes through the plane at an angle from 3011 to 600. 1
14. A valve as claimed in any one of claims 10 to 13, wherein the housing is divided into first and second parts along a second plane which coincides with the first plane when the composite valve element has been rotated into a fully closed position, the inlet and outlet being located in separate parts of the housing.
15. A valve as claimed in any one of claims 9 to 14, wherein the inlet and outlet are longitudinally disposed along a third axis which passes through the centre of the substantially spherical or part-spherical portion of the composite valve element and which substantially coincides with the second axis when the composite valve element has been rotated into a fully open position.
16. A valve as claimed in any preceding claim, wherein the first and second parts of the housing are each provided with a Range defining a mating surface, and wherein a clip or annular sealing member is provided to hold the flanges and hence the mating surfaces together when the valve is in its assembled condition.
17. A valve as claimed in any preceding claim, wherein a valve seat is provided on a surface of the valve chamber where each of the inlet and outlet open thereinto.
18. A valve as claimed in any one of claims 7 to 17 depending ultimately from claim 7, wherein the trunnions are rotatably retained within the sleeves by way of bolts or the like.
19. A valve substantially as hereinbefore described with reference to the accompanying drawings.