GB2236829A

GB2236829A - A valve assembly

Info

Publication number: GB2236829A
Application number: GB8923201A
Authority: GB
Inventors: Spencer Nicholson
Original assignee: OLIVER ENGINEERING Ltd
Current assignee: OLIVER ENGINEERING Ltd
Priority date: 1989-10-14
Filing date: 1989-10-14
Publication date: 1991-04-17
Also published as: GB8923201D0

Abstract

A valve comprising an integral body (1) defining a straight flow passage (6) controlled by a central (9a) and two flanking (7a, 8a) valve elements characterised in that the central valve element is a T-ported ball for establishing a connection with a branch flow passage (10). The valve elements are operatively connected to respective handles (7d, 8d, 9d) unitary with interengaging cams adapted to interlock the handles against undesirable opening configurations of the valve elements. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO VALVES This invention relates to valves and more particularly to a multi-purpose valve of the kind in which a flow passage is controlled by spaced apart first and second flow control valves and a further control valve is provided for controlling the flow of fluid to or from the flow passage intermediate said first control valves.

It is known to make valves known as double block and bleed valves to this configuration. A traditional double block and bleed valve may comprise separate components bolted together to define the flow passage in which the spaced apart first and second control valves or block valves are located, the further control or bleed valve being disposed in a branch pipe similarly connected to the flow passage. All these control valves use ball valve elements.

It is an object of the present invention to provide an integrated valve of the defined configuration with valve elements all in line enabling a more compact lightweight and robust design.

According to the present invention there is provided a valve of the defined configuration comprising an integral body defining a straight flow passage controlled by a central and two flanking valve elements characterised in that the central valve element is a T-ported ball for establishing a connection with a branch flow passage.

The invention will now be further described by way of example only with reference to the accompanying drawings in which: Fig. 1 is a longitudinal section of one embodiment of valve according to the invention, on line I-I of Fig. 2; Fig. 2 is an end elevation from the right hand end of Fig. 1, and Figs. 3 to 6 are diagrams illustrating different stages in the operation of the valve and a cam interlocking system thereof.

Referring now to the drawings, the exemplary valve comprises an integral body 1 with a circular flange 2 or any other process connection detail allowing installation into a wide variety of applications and typically a square section shank 3 extending axially therefrom. In the flanged version of the assembly, the flange 2 has openings 4 for four bolt fasteners (not shown) whereby the valve can be connected to a process line flange 5 indicated in dotted line in Fig. 1.

The valve 1 has a central, straight flow passage 6 controlled by primary and secondary isolating valves 7, 8 flanking a central vent valve 9 connecting the main flow passage 6 to a vent passage 10. The end of the flow passage 6 remote from the flange 2 (or process connection) is provided with an adaptor 11 for connection of for example a pressure gauge instrument (not shown).

The valve element of each of the valves 7, 8 and 9 is a ball 7a, 8a and 9a having (in the case of the valves 7, 8) a straightthrough passage 7b, 8b and (in the case of the ball 9a) a three way passage 9b. Each of the balls 7a, 8a and 9a is rotatable about an axis 7c, 8c, 9c by a respective handle 7d, 8d and 9d connected to the respective ball by a spigot and socket connection in known manner. It will be noted that the flow passages 7b, 8b of the balls 7, 8 are aligned with the flow passage 6 when the respective valves 7, 8 are open and are disposed at right angles thereto when these valves are closed. In contrast, the ball 9 does not interrupt the flow passage 6 in the fully open or fully closed condition thereof.

In use of the valve, an instrument, for example a pressure gauge, is attached to the adaptor 11 at the end of the flow passage 6. With the primary and secondary isolating valves 7, 8 open and the vent valve 9 closed (Fig. 6) the pressure gauge can be connected directly to the pressure line 5 to sense the pressure thereof. Before detaching the instrument from the adaptor 11 the flow passage 6 downstream of the primary isolating valve 7 must be vented and this is done through the connection 10 after the primary isolating valve 7 has been moved into the closed position and the venting valve 9 into the open position (Fig. 4).

Each of the handles 7d, 8d and 9d is rotationally fast with a part circular cam 7e, 8e and 9e disposed in a common plane so as to interact with each other and prevent undesirable operating conditions for example opening of the primary isolating valve while the venting valve is open.

Referring firstly to Fig. 3 it will be seen that the primary and secondary isolating valves are closed with the primary isolating and venting valves locked, the latter being in the open position. Fig. 4 shows an alternative permissible condition arrived at by rotating the secondary isolating valve clockwise through 900 to free the venting valve. In this condition the secondary isolating valve is open, the primary isolating valve locked close and the venting valve open but not locked. Fig. 5 shows the position after rotating the venting valve clockwise or anti-clockwise through 1800 to lock the secondary isolating valve and free the primary isolating valve. In this condition the primary isolating valve is closed but not locked whereas the secondary isolating valve is locked open and the venting valve is closed. Finally, in Fig. 6 the primary isolating valve has been rotated anticlockwise through 900 to lock the venting valve and hence the secondary isolating valve. In this condition the primary and secondary isolating valves are open, the venting valve is closed, and the venting and secondary isolation valves are locked.

The design has provision to accommodate any other desirable operating sequence for the product by variation in size and shape of the cam discs.

Claims

CLAIMS:

1. A valve of the defined configuration comprising an integral body defining a straight flow passage controlled by a central and two flanking valve elements characterised in that the central valve element is a T-ported ball for establishing a connection with a branch flow passage.

2. A valve as claimed in claim 1, wherein the valve elements are operatively connected to respective handles unitary with interengaging cams adapted to interlock the handles against undesirable opening configurations of the valve elements.

3. A valve substantially as herein described with reference to the accompanying drawings.