GB2193298A

GB2193298A - Spherical ball and taper plug valves

Info

Publication number: GB2193298A
Application number: GB08716333A
Authority: GB
Inventors: Robert Brian Hall
Original assignee: Pegler Ltd
Current assignee: Pegler Ltd
Priority date: 1986-07-29
Filing date: 1987-07-10
Publication date: 1988-02-03
Also published as: GB8618434D0; GB8716333D0

Abstract

A spherical ball or taper plug valve has a valve member (12) provided with a through bore (14) which by means of a handle (18) mounted on an operating spindle (16) can be brought into alignment with the flow passage through the valve or brought into a position at right angles to the flow passage. In order that the maximum rate of flow of fluid through the valve can be adjusted fairly accurately, the valve is provided with a detent plate (26) with spline location on the operating spindle (16) so that it can be re-located thereon in small increments of movement for co-operation with a stop (24) provided on the valve housing. The handle (18) also carries a lug (22) which co-operates with a further stop (24) to limit the closing movement of the spindle (16). <IMAGE>

Description

SPECIFICATION Spherical ball and taper plug valves The invention relates to spherical ball and taper plug valves.

In a spherical ball valve or a taper plug valve the valve member, that is to say the spherical ball member or the taper plug member, as the case may be, is provided with a through bore which by movement of the valve member through 90 degrees can be either brought into alignment with the flow passage through the valve or brought into a position at right angles to the flow passage. Stop means are normally provided to limit the angular movement of the valve member in the opposite directions of movement so that it is a very simple operation to re-adjust the valve to a fully open or fully closed condition.However, there are times when it is required to adjust the rate of flow of fluid through a spherical ball or taper plug valve, by altering the position of the through bore relative to the flow passage through the valve, and in these circumstances it is usual for an operative to simply use his own judgement or to resort to trial and error. The invention has for its object to provide a remedy.

According to the invention, a spherical ball or taper plug valve is provided with a lever handle a part of which is arranged to abut against respective valve body stops to limit the extent of movement of the valve member in opposite directions between fully open and fully closed conditions, and in addition is provided with a detent plate, capable of being adjustably positioned on the operating spindle to which the lever handle is connected and of coming into contact with one or other of the valve body stops before the valve member reaches its fully open or fully closed condition, the arrangement being such that by the appropriate location of the detent plate the range of movement permitted by the lever handle moving between the respective body stops is correspondingly reduced.The detent plate will preferably have spline location on the operating spindle so that it can be re-located thereon in small increments of movement. The part of the lever handle arranged to abut against the respectiye valve body stops will preferably be a downturned lug and in this case the detent plate will be provided with a similar downturned iug.

In order that the invention may be fully understood and readily carried into effect, the same will now be described, by way of example only, with reference to the accompanying drawings, of which: Figure I is a side elevation of a spherical ball valve embodying the invention, Figure 2 is a plan view thereof, and Figure 3 is a view similar to Figure 2, but with a lever handle removed.

Referring now to the drawings, the spherical ball valve there illustrated has a cast body 10 within which there is located, in known manner, a valve member 12 in the form of a spherical ball with a through bore 14. The arrangement is such that when the valve member is orientated as shown in Figure 1, the throughbore is aligned with the flow passage through the valve but when rotated through 90 degrees about its vertical axis the through bore is brought into a position at right angles to the flow passage.

An operating spindle 16 upstanding from the valve member carries a lever handle 18 by means of which the valve member can be turned. The lever handle has positive location on the spindle and is secured thereon by means of a locknut 20.

The lever handle 18 is provided, as shown, with a downturned lug 22 and this is provided so that, by virtue of a pair of stop members 24, 24 which have been cast integrally with the body 10, the maximum range of movement of the valve member about its vertical axis is through 90 degrees from the fully open position to the fully closed position and back again. However, to enable the rate of flow of fluid through the valve to be adjusted to some predetermined value, that is to say to enable the valve to be opened to only a partially open position or to inhibit its complete closure, the valve is provided with a detent plate 26 which also has splined location on the operating spindle so that it is capable of being adjustably positioned thereon in a pre-determined position relative to the operating spindle.The detent plate is provided with a downturned lug 28 similar to the downturned lug 22 of the lever handle. The arrangement is such that, depending upon the relative locations of the lever handle and detent plate, the downturned lug 28 of the detent plate can come into contact with one or other of the stop members 24, 24 before the valve member reaches its fully open or fully closed condition. Although shown in Figure 2 as being in advance, in a clockwise djrection of movement, of the downturned lug 22 of the lever handle, it will be understood that the downturned lug 28 of the detent plate 26 can be located on either side of the lug 22 depending on the range of free movement required.

Thus there is provided a spherical plug valve through which the rate of flow of fluid can be easily adjusted, that is to say brought to a predetermined position of adjustment somewhere between the fully open and fully closed positions. Consequently, for example, the valve is ideally suited for use in process control plant where an unskilled operative can be instructed to make control adjustments at appropriate times without having to use any skill or judgement. However, it will be understood that the invention is not only applicable to spherical plug valves. The invention is equally applicable to a taper plug valve which of course operates in a very similar manner to a spherical plug valve.

Claims

1. A spherical ball or taper plug valve provided with a lever handle a part of which is arranged to abut against respective valve body stops to limit the extent of movement of the valve member in opposite directions between fully open and fully closed conditions, and in addition provided with a detent plate, capable of being adjustably positioned on the operating spindle to which the lever handle is connected and of coming into contact with one or other of the valve body stops before the valve member reaches its fully open or fully closed condition, the arrangement being such that by the appropriate location of the detent plate the range of movement permitted by the lever handle moving between the respective body stops is correspondingly reduced.

2. A spherical ball or taper plug valve according to claim 1, in which the detent plate has spline location on the operating spindle so that it can be re-located thereon in small increments of movement.

3. A spherical ball or taper plug valve according to either one of the preceding claims, in which the part of the lever handle arranged to abut against the respective valve body stops is a downturned lug.

4. A spherical ball or taper plug valve according to claim 3, in which the detent plate is also provided with a downturned lug.

5. A spherical ball or taper plug valve constructed, arranged and adapted to operate substantially as hereinbefore described with reference to and as illustrated by the accompanying drawings.