GB2192973A - Ball valve - Google Patents

Abstract

A ball valve comprises a body 10 defining an inlet 4, an outlet 11, and a spindle opening 19 communicating with a passageway defined through the body between the inlet and outlet. A ball valve member 14 supports a spindle 18 which extends through the spindle opening 19 and is rotatable between an open posltion, in which fluid can flow through the ball valve member between the inlet and outlet, and a closed position. A first O-ring seal 16, 17 is trapped between the valve member and a face of the valve body so as to seal the passageway when the ball valve member is in the closed position, and a second O- ring seal 25 is positioned between the spindle and a wall of the valve spindle opening and engages the ball valve member so as to seal the valve spindle opening. The second O-ring seal is retained in position by a manually actuable control member 5 which engages the valve member spindle and obstructs the end of the valve spindle opening remote from the passageway between the inlet and outlet. <IMAGE>

Description

SPECIFICATION Ball valve The present invention relates to a ball valve.

Fluid distribution systems such as those used for deliverying water to central heating radiators generally comprise valves secured to the inlet and outlet of the radiator. In such circumstances there is plenty of space available for a relatively bulky valve structure.

There are however many applications where a more compact structure would be preferred and in such circumstances a ball valve assembly can be used.

Conventional ball valve assemblies comprise a body defining a passageway in which the ball valve member is located. The ball valve member defines a passageway which if aligned with the main passageway of the valve assembly enables fluid to pass therethrough. The ball valve can however be rotated through 90 so as to obstruct the valve passageway. The ball valve member is moved by rotation of a spindle which projects through a side wall of the valve body and it is necessary not only to seal the face of the ball valve relative to the passageway through the valve body but also to seal the opening through which the valve member spindle extends.

It is desirable to maintain the dimensions of a ball valve assembly as small as possible, but it has not previously been thought possible to insert a ball valve member incorporating an integral spindle through the fluid passageway unless the spindle is so short as to make it difficult to secure an operating handle thereto.

If the spindle is of a convenient length, a large spindle opening is required to enable the ball valve member to be rotated so as to cause the spindle to project through the spindle opening. Such a large spindle opening requires a threaded sealing member which is engaged around the valve member spindle after its insertion. Because of this problem it has been conventional practice either to insert the ballvalve member through the spindle opening and subsequently screw in an additional member to seal the space defined around the spindle in that opening or to weld the valve body into its final configuration after insertion of the ball valve member.An alternative approach has been to insert a separate spindle through the fluid passageway, a flange retaining the spindle in the spindle opening, and then to insert a ball valve member, the spindle and ball valve member being interengaged by a cooperating key and keyway structure. All of these approaches result in structures which are relatively difficult to manufacture and are therefore expensive as compared with the conventional relatively bulky valve assemblies.

It is an object of the present invention to obviate or mitigate the above problems.

According to the present invention there is provided a ball valve comprising a body defining an inlet, an outlet, and a ball valve member spindle opening communicating with a passageway defined through the body between the inlet and outlet, a ball valve member supporting a spindle which extends through the spindle opening, the ball valve member being rotatable by turning the spindle from an open position in which fluid can flow through the ball valve member between the inlet and outlet and a closed position in which the ball valve member obstructs the passageway between the inlet and outlet, a first sealing means which engages the ball valve member and the valve body so as to seal the said passageway when the ball valve member is in the closed position, and a second sealing means which engages the ball valve member and the body so as to seal the valve spindle opening, wherein each said sealing means comprises an O-ring, the first sealing means O-ring being trapped between the valve member and a face of the valve body, and the second sealing means O-ring being positioned between the spindle and a wall of the valve spindle opening, the said second sealing means O-ring being retained in position by a manually actuable member which engages the valve member spindle and obstructs the end of the valve spindle opening remote from the passageway between the inlet and outlet.

Preferably, the first sealing means comprises two O-rings, one O-ring being located between the ball valve member and the inlet and the other O-ring being positioned between the ball valve member and the outlet. One of the O-rings can be trapped between the ball valve member and a flange formed in the valve body and the other O-ring of the first sealing means may be trapped between the ball valve member and a ring secured in the said passageway. The said ring may comprise a bearing ring which contacts one side of the O-ring and a circlip which retains the bearing ring in position.

In ball valves in accordance with the present invention the spindle opening may be relatively large so that the ball valve member may be inserted through the passageway between the inlet and outlet and then rotated so that the spindle projects through the spindle opening.

The relatively large space defined between the spindle and the spindle opening can be dimensioned to receive a simple O-ring which bears on one side against a shoulder defined by the ball valve member and which is prevented from sliding along the spindle by a surface defined by the actuating member which projects a short distance into the valve spindle opening.

An embodiment of the present invention will now be described by way of example with reference to the accompanying drawings, in which Fig. 1 illustrates a wall mounted box into which a ball valve member in accordance with the present invention can be inserted; Fig. 2 is an exploded view of the components of the assembly illustrated in Fig. 1; Fig. 3 is a sectional view through the ball valve illustrated in Fig. 2; Fig. 4 is a perspective view of a ball valve member incorporated in the ball valve of Fig.

3; and Figs. 5 and 6 are respectively end views of the ball valve member and a manually actuable member of the ball valve shown in Fig. 3, the sections being taken on lines 5-5 and 6-6 of Fig. 3.

Referring to Fig. 1, the illustrated assembly comprises a wall box 1 supporting a cover 2 secured thereto by screws 3. The box encloses the body of a ball valve in accordance with the present invention, an inlet 4 and actuating member 5 projecting through the cover 2. A pipe 6 and nut 7 (shown in outline only) enable the pipe 6 to be connected to the inlet 4. The end of the actuating member 5 defines a slot 8 into which a tool or coin can be inserted so as to rotate the actuating member.

Referring now to Fig. 2, this illustrates the components of the assembly illustrated in Fig.

1. The box 1 supports posts 9 defining threaded bores for receiving the screws 3 so as to secure the cover to the box 1. The ball valve comprises a body 10 which defines a passageway extending between the inlet 4 and an outlet 11. The body 10 supports a pair of flanges 12 which enable the body to be secured to the box.

Referring now to Figs. 3 to 6, the internal structure of the ball valve will be described.

The body 10 defines a passageway 13 extending between the inlet 4 and the outlet 11.

A ball valve member 14 is located in this passageway. The ball valve member defines a bore 1 5 which in the position of the ball valve member shown in Fig. 3 enables fluid to flow from the inlet 4 to the outlet 11. The ball valve member can however be rotated through 90 so that thebore 15 is perpendicular to the passageway 13, thereby obstructing the passageway 13.

A first sealing means in the form of O-rings 16 and 17 performs the functions of on the one hand preventing leakage between the ball valve member and the body and on the other hand provides bearing surfaces for supporting the ball valve member as it is rotated. The ball valve member 14 also supports a spindle 18 which extends through a spindle opening 19, the spindle defining a threaded bore 20 into which a retaining screw 21 can be inserted so as to secure the actuating member 5 on the spindle. A brass washer 22 is engaged between the actuating member 5 and the screw 21.

The illustrated ball valve is assembled by first inserting the O-ring 16 into the body 10 so that it assumes the position shown. The ball valve member is then pushed, spindle first through the outlet 11 and rotated so that the spindle 18 projects through the spindle opening 19. The size of the spindle opening is sufficient to enable the relatively narrow spindle to be pushed therethrough. The O-ring 17 is then pushed through the outlet 11 to the position shown in Fig. 3. It is then retained in that position by pushing in a bearing ring 23 and retaining the bearing ring in position by means of a circlip 24 which is received in an appropriately dimensioned annular slot.

With the ball valve assembled as described above, the O-rings 16 and 17 prevent any fluid leaking around the valve member 14 when the valve member is in either the fully open position as shown in Fig. 3 or in the fully closed position to which it can be moved by rotating it through 90 from the position shown in Fig. 3. When the ball valve member is rotated only partially, for example by 45" from the position shown, the bore 15 bypasses both of the rings 16 and 17 and it is therefore necessary to seal the gap defined between the spindle 18 and the spindle opening 19.

This sealing is achieved by inserting a further O-ring 25 into the spindle opening 19 so that it bears against a shoulder 26 (best seen from Fig. 4) defined by the valve member 14.

The shoulder 26 prevents the O-ring being pushed out of position to the right in Fig. 3.

The O-ring 25 is retained against being pushed out of position to the left in Fig. 3 by an end face 27 of the actuating member 5.

When the actuating member is secured in position by the screw 21 the end face 27 extends a short distance into the spindle opening 19. Thus, the O-ring 25 is firmly retained in position and provides an effective seal around the spindle 18.

As shown in Figs. 5 and 6, the spindle defines flats 28 which mate with corresponding flats 29 on the actuating member 5. The actuating member 5 also defines a cut-out 30 which clears an edge 31 of the valve body.

The cut-out 30 extends around only a portion of the axis of the actuating member 5 however and accordingly limits the rotation of the actuating member to approximately 90". It is thus clear from the orientation of the slot 8 as to whether or not the valve is fully open, fully closed or at an intermediate position. The actuating member 5 is shown in Fig. 2 in the fully closed position in which the bore 15 extends at right angles to the passageway 13.

It will be appreciated from the above description that all of the components of the ball valve can be manufactured from for example brass relatively cheaply to provide a reliable, compact and economic assembly. The ball valve member 14 can beeasily inserted through the passageway defined by the ball valve and therefore simple assembly tech niques can be adopted.

It would be possible to incorporate in the inlet 4 a spring-loaded valve member which automatically obstructs the passageway 13 unless an appropriate connection has been made to the inlet 4. This would mean that leakage from the passageway 13 through the inlet 4 could not occur evn if the passageway 13 was full of fluid when the inlet was disconnected from an associated supply pipe.

Claims (6)

1. A ball valve comprising a body defining an inlet, an outlet, and a ball valve member spindle opening communicating with a passageway defined through the body between the inlet and outlet, a ball valve member supporting a spindle which extends through the spindle opening, the ball valve member being rotatable by turning the spindle from an open position in which fluid can flow through the ball valve member between the inlet and outlet and a closed position in which the ball valve member obstructs the passageway between the inlet and outlet, a first sealing means which engages the ball valve member and the valve body so as to seal the said passageway when the ball valve member is in the closed position, and a second sealing means which engages the ball valve member and the body so as to seal the valve spindle opening, wherein each said sealing means comprises an O-ring, the first sealing means O-ring being trapped between the valve member and a face of the valve body, and the second sealing means O-ring being positioned between the spindle and a wall of the valve spindle opening, the said second sealing means O-ring being retained in position by a manually actuable member which engages the valve member spindle and obstructs the end of the valve spindle opening remote from the passageway between the inlet and outlet.

2. A bell valve according to claim 1, wherein the first sealing means comprises two O-rings, one O-ring being located between the ball valve member and the inlet and the other O-ring being positioned between the ball valve member and the outlet.

3. A ball valve according to claim 2, wherein one of the O-rings is trapped between the ball valve member and a flange formed in the valve body, and the other O-ring of the first sealing means is trapped between the ball valve member and a ring secured in the said passageway.

4. A ball valve according to claim 3, wherein the said ring comprises a bearing ring which contacts one side of the O-ring and a circlip which retains the bearing ring in position.

5. A ball valve according to any preceding claim, wherein the said second sealing means O-ring bears on one side against a shoulder defined by the ball valve member and is prevented from sliding along the spindle by a surface defined by the manually actuable member which projects a short distance into the valve spindle opening.

6. A ball valve substantially as hereinbefore described with reference to the accompanying drawings.