GB2209580A

GB2209580A - A butterfly valve

Info

Publication number: GB2209580A
Application number: GB8720907A
Authority: GB
Inventors: David Colston Beauchamp
Original assignee: HATTERSLEY HEATON Ltd
Current assignee: HATTERSLEY HEATON Ltd
Priority date: 1987-09-05
Filing date: 1987-09-05
Publication date: 1989-05-17
Anticipated expiration: 2007-09-05
Also published as: GB2209580B; GB8720907D0

Abstract

A butterfly valve comprising a disc form valve member 2 rotatably disposed in a valve body 1 has means for preventing movement of the valve member beyond fully-open position. Preferably member 2 and body 1 each carry a stop with two stop faces. One cooperating pair of stop faces 8 and 9 abut when the valve is in the fully open position and the other pair (6 and 7 Fig. 2) when the valve is in the fully closed position. This arrangement reduces angular deflection and uneven seat wear. <IMAGE>

Description

A BUTTERFLY VALVE The present invention relates to a stop mechanism for a butterfly valve.

In such a valve it is necessary to ensure as far as possible that when in the closed position, the valve member is correctly orientated in the valve body, that is with its face at right angles to the flow axis of the valve. Valves are known in which stops are provided externally of the valve on the shaft on which the valve member is mounted, but this can lead to inaccuracy because there may be twisting of the shaft between the stops and the valve member Valves are also known in which stops are provided internally of the valve body which are abutted by the periphery of the valve member when the member is in the closed position but this can also lead to inaccuracy because the shaft flexes under pressure and the member may tend to pivot around the stop rather than about the shaft leading to uneven wear of the valve seat.It is an object of an embodiment of the invention to mitigate these disadvantages.

According to the present invention, there is provided a butterfly valve comprising a valve body, a valve member rotatably disposed within the valve body for movement between a first position in which the member prevents fluid flow through the valve and a second position in which the fluid flow through the valve is permitted and means for preventing movement of the valve member beyond the fully open position.

In a preferred embodiment of the invention the means for preventing movement comprises a stop on the valve body and a stop on the valve member. Each stop comprises two stop faces which are operative to respectively abutt the two stop faces on the other stop. One pair of stop faces abutt with the valve member in the fully closed position and the other pair abutt with the valve member in the fully open position. The first pair of stop faces, abutt in a plane at right angles to the plane of the front face of the valve member. The other pair abutt in a plane at 450 to this front face plane.

In order that the invention may be more clearly understood, one embodiment thereof will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a partial diagrammatic sectional view of a butterfly valve, in a closed position, Figure 2 is a partial diagrammatic sectional view of the butterfly valve of Figure 1 in an open position, Figure 3 is a perspective parital view of a detail of the valve of Figures 1 and 2, and Figure 4 is a perspective partial view also of a detail of the valve of Figures 1 and 2.

Referring to the drawings, the butterfly valve comprises a valve body 1 in which a valve member 2 is rotatably disposed. The valve member 2 is mounted on a shaft 3 which is in turn mounted in the valve body. Both the valve member 2 and the valve body 1 are provided with stops 4 and 5. These stops cooperate in two different positions of the valve, the fully closed position (shown in Figure 1) and the fully open position (shown in Figure 2).

As can be seen both stops have complementary faces to provide areas of contact in both positions. Thus faces 6 and 7 cooperate in the closed position of the valve and faces 8 and 9 in the open position.

The stop 4 is shown in more detail in Figure 3 and the stop 5 is shown in more detail in Figure 4. Figure 3 shows the valve member 2 from the back. This defines a bore 10 extending from top to bottom which accept the shaft 3 (not shown). At one end of this bore the material surrounding the bore is formed to provide the two stop faces 6 and 8.

Stop face 6 is at 900 to the plane of the front face of the valve member 2 and stop face 8 is at 450 to the front face of the valve member 2.

Figure 4 shows the formation for the stop faces 7 and 9 on the valve body. This comprises a boss 11 which defines an aperture 12 through which the shaft 3 (not shown) extends. Stop face 7 is parallel to the front face of the valve member 2 and stop face 9 is at 450 to this front face.

With the above described arrangement, when the valve is in the closed position, the valve member 2 is firmly held and angular deflection of it is reduced. With the valve closed and pressure applied in either direction, the member 2 is allowed to deflect in a linear direction in line with the flow, and also hold even deflection into and out of the valve body 1. This will reduce angular deflection created by the eccentrically mounted member 2 having imbalanced pressure area and eliminate uneven seat wear.

The presence of the open stops prevent the valve member being opened beyond the truly open position.

It will be appreciated that the above embodiment has been described by way of example only and that many variations are possible without departing from the invention.

Claims

1. A butterfly valve comprising a valve body, a valve member rotatably disposed within the valve body for movement between a first position in which the member prevents fluid flow through the valve and a second position in which the fluid flow through the valve is permitted and means for preventing movement of the valve member beyond the fully open position.

2. A butterfly valve as claimed in claim 1, in which the means for preventing movement comprises a stop on the valve body and a stop on the valve member.

3. A butterfly valve as claimed in claim 2, in which each stop comprises two stop faces which are operative to respectively abutt the other two stop faces.

4. A butterfly valve as claimed in claim 3, in which one pair of stop faces on the body and member respectively abutt with the valve member in the fully closed position.

5. A butterfly valve as claimed in claim 3 or 4, in which one pair of stop faces on the body and member respectively abutt with the valve in the fully open position.

6. A butterfly valve as claimed in claim 4, in which the pair of stop faces abutt in a plane at right angles to the plane of the front face of the valve member.

7. A buttefly valve as claimed in claim 5, in which the pair of stop faces abutt in a plane at 450 to the plane of the front face of the valve member.

8. A butterfly valve as claimed in any of claims 2 to 7, in which the valve member is supported on a shaft extending through an aperture in the valve body and the stop on the valve body is formed on a boss on the body surrounding the aperture.

9. A butterfly valve as claimed in any of claims 2 to 7, in which the valve member is supported on a shaft extending through an aperture in the valve member and the stop on the member comprises a formation on the valve member surrounding the aperture.

10. A butterfly valve substantially as hereinbefore described with reference to the accompanying drawings.