GB2281372A - Locking cover for a valve - Google Patents

Abstract

A lockable cover assembly for a valve comprises a base 8 having first 11 and second 12 apertures, and a cap 1 having a first projection 4 adapted to engage the first aperture, and a second projection 6 adapted to engage the second aperture. Locking means are provided for locking the first projection in engagement with the first aperture. When the first projection is locked in engagement with the first aperture, disengagement of the second projection from the second aperture is prevented, thereby securing the cap to the base. In the preferred embodiment flange 7 on projection 6 is inserted through end portion 14 of second aperture 12 and projection 6 is then slid to the opposite end of slot 13. Projection 5 is then inserted into first aperture 11 and the staple of a padlock or multihasp is passed through transverse bore 5 through projection 4. <IMAGE>

Description

LOCKING CAP The invention concerns a locking cap, in particular for a valve which controls the flow of a fluid in a conduit, which cap will prevent accidental opening of the valve while maintenance work is proceeding which involves the conduit, and which will protect the valve against vandalism and sabotage.

When maintenance work is proceeding on a plant which involves conduits through which hazardous fluids can pass, it is desirable for the safety of the maintenance workers that any valves which control the flow of fluids into the part of the plant in which work is in progress should be capable of being locked in a closed position to prevent passage of the fluid to that part. Also, in chemical plants which are vulnerable to acts of vandalism or malicious damage, security would be improved if valves controlling the flow of fluid could not be tampered with.

WO 92/17723 describes a lockable cap for the handle of valve which is used to control the flow of fluid in a pipeline. The cap is made in two semicylindrical halves which surround the handle and are locked together to prevent access to the handle. The handle of the valve can be set in any desired position before the cap is applied.

According to the present invention there is provided a valve assembly comprising a valve body and a control member, a lockable cover assembly being provided for covering the control member and comprising a base having a first aperture and a second aperture, and a cap having a first projection which is adapted to engage the first aperture, and a second projection which is adapted to engage the second aperture, locking means being provided for locking the first projection in engagement with the first aperture, the arrangement being such, when the first projection is locked in engagement with the first aperture, disengagement of the second projection from the second aperture is prevented, thereby ensuring securement of the cap to the base by engagement of the two projections with their respective apertures.

An end region of the first projection may be provided with a bore which is adapted to accommodate a locking element of the locking means.

The base may be formed integrally with the body of the valve, for example by a casting process.

Alternatively, the base may be secured to the body of the valve by means of screws or other known fixing devices. By this later method, existing valves can be adapted to be rendered lockable by the device according to the invention. Preferably, the base comprises a plate, which may be formed in two or more pieces, each piece being rigidly secured to the body of the valve.

The first aperture of the base is preferably circular in shape for ease of manufacture, but may also be, for example, rectangular or polygonal. The first projection of the cap preferably has a cross-section which conforms to the shape of the first aperture.

The second aperture of the plate may be formed as a slot with an enlarged region. An end region of the second projection may comprise an enlarged portion, which is adapted to pass through the enlarged region of the slot, but which is unable to pass through the remainder of the slot. The remainder of the second projection is preferably adapted to slide in the said remainder of the slot. Preferably, the slot is rectilinear, and the enlarged region comprises a circular portion. However, the slot may alternatively be curved and/or the enlarged region may be of rectangular or polygonal shape.

The base may, of course, include other apertures which cooperate with corresponding projections on the cap to enhance the locking mechanism.

Also, the base may have a further aperture through which the control member of the valve passes.

The cap may be of a metallic material, for example mild steel, stainless steel, aluminium, brass or other ferrous or non-ferrous alloys. Alternatively the cap may be of a plastics material provided that the material is sufficiently strong to prevent the cap from being wrenched off by force. Preferably the first and second projections are fixed to the cap by welding or are formed integrally with the cap. The enlarged end portion of the second projection may be formed integrally with the remainder of the projection, or may alternatively be formed by welding a body of larger cross section on to the remainder.

The locking element may be lockable staple, which may be provided by a conventional padlock.

Alternatively the lockable staple may be that of a device known as a "multihasp". A multihasp is a known device which has two pincer-like jaws which can pass through the bore formed in the lower end of the first projection, the jaws being lockable in the closed position by means of two or more padlocks. This device is provided for the security of two or more maintenance workers who may be working on a particular plant at the same time. Each worker is able to lock his own personal padlock on to the multihasp with the result that the position of the valve can not be changed until all of the workers have removed their padlocks.

For a better understanding of the present invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a diagrammatic isometric view of a valve locking device in accordance with the invention.

Figure 2 is a plan view of the valve locking device shown in Figure 1.

Figure 3 is a side elevation of the valve locking device shown in Figure 1.

A locking device for a valve which controls the flow of a fluid in a conduit comprises a cylindrical cap 1 of stainless steel which is closed at one end 2.

A radially extending lug 3 is welded to the side wall of the cap, near the open end, to which is welded a first projection 4 of circular cross section. Near its lower end the first projection is pierced with a transverse bore 5 of diameter such that it can receive the staple of a padlock or of a multihasp.

Diametrically opposite to the lug 3 there is welded to the side wall of the cap 1 an L-shaped second projection 6 of circular cross section, to the lower end of which is welded an enlarged portion 7 of circular cross section.

The locking device also comprises a rectangular plate 8 which is provided with a central aperture 9 which accommodates the shoulder portion of the body of a valve for use in a fluid conduit. The plate may be rigidly fixed to the body of the valve by means of screws (not shown) which pass through holes 10 formed in the plate 8. The plate is also provided with a first aperture 11 of circular cross section and diameter slightly larger than that of the first projection 4, and with a second aperture 12 which comprises a straight elongated slot 13 and a circular end portion 14 of diameter larger than the width of the slot 13 and slightly larger than the diameter of the enlarged end portion 7 of the second projection 6. The width of the slot 13 is slightly greater than the diameter of the main portion of the second projection 6.

In use, the plate 1 is first securely attached to the body of a valve in a conduit through which a fluid can flow. The second projection 6 of the cap 1 is then inserted into the enlarged end portion 14 of the second aperture 12 and is slid along the slot 13 to the further end. This enables the first projection 4 to be inserted into the first aperture 11, and the cap can then be locked in place by passing the staple of a padlock or of a multihasp through the bore 5.

In order to remove the cap, the staple of the locking device must first be removed from the bore 5.

It is then possible to withdraw the first projection 4 from the first aperture 11. Only then can the second projection 6 be slid along the slot 13 to the enlarged end portion 14 of the second aperture 12 so that the second projection can be removed from this aperture.

Claims (22)

CLAIMS:

1. A valve assembly comprising a valve body and a control member, a lockable cover assembly being provided for covering the control member and comprising a base having a first aperture and a second aperture, and a cap having a first projection which is adapted to engage the first aperture, and a second projection which is adapted to engage the second aperture, locking means being provided for locking the first projection in engagement with the first aperture, the arrangement being such, when the first projection is locked in engagement with the first aperture, disengagement of the second projection from the second aperture is prevented, thereby ensuring securement of the cap to the base by engagement of the two projections with their respective apertures.

2. A valve assembly according to claim 1, wherein an end region of the first projection is provided with a bore which is adapted to accommodate a locking element of the locking means.

3. A valve assembly according to claim 1 or 2, wherein the base is formed integrally with the body of the valve.

4. A valve assembly according to claim 1 or 2, wherein the base is secured to the body of the valve by means of a fixing devices.

5. A valve assembly according to any preceding claim, wherein the base comprises a plate which is formed in two or more pieces, each piece being rigidly secured to the body of the valve.

6. A valve assembly according to any preceding claim, wherein the first aperture of the base is circular in shape.

7. A valve assembly according to any preceding claim, wherein the first projection of the cap has a cross-section which conforms to the shape of the first aperture.

8. A valve assembly according to any preceding claim, wherein the second aperture of the plate is formed as a slot with an enlarged region and an end region of the second projection comprises an enlarged portion which is adapted to pass through the enlarged region of the slot, but which is unable to pass through the remainder of the slot.

9. A valve assembly according to any preceding claim, wherein the second projection includes an intermediate portion adapted to slide in the said remainder of the slot.

10. A valve assembly according to claim 8 or 9, wherein the slot is rectilinear and the enlarged region comprises a circular portion.

11. A valve assembly according to any preceding claim, wherein the cap is formed of a metallic material.

12. A valve assembly according to claim 11, wherein the metallic material is mild steel, stainless steel, aluminium, brass or other ferrous or non-ferrous alloys.

13. A valve assembly according to any one of claims 1 to 10, wherein the cap is formed of a plastics material.

14. A valve assembly according to any preceding claim, wherein the first and second projections are secured to the cap by welding.

15. A valve assembly according any one or more of claims 1 to 13, wherein the first and second projections are formed integrally with the cap.

16. A-valve assembly according to claim 8 or any one or more of claims 9 to 15 when appendant to claim 8, wherein the enlarged end portion of the second projection is formed integrally with the remainder of the projection.

17. A valve assembly according to claim 8 or any one or more of claims 9 to 15 when appendant to claim 8, wherein the enlarged end portion of the second projection is formed by welding a body of larger cross section on to the remainder.

18. A valve assembly according to any preceding claim, wherein the locking element is a lockable staple.

19. A valve assembly according to any preceding claim, wherein the lockable staple is a multihasp.

20. The lockable cover assembly as defined in any one of the preceding claims.

21. A valve assembly as claimed in claim 1, substantially as hereinbefore described, with reference to the accompanying drawings.

22. A lockable cover assembly, substantially as hereinbefore described, with reference to the accompanying drawings.