GB2312731A

GB2312731A - Valve position indicator and stop

Info

Publication number: GB2312731A
Application number: GB9708985A
Authority: GB
Inventors: Christopher Vernon Whittaker; Andrew Harrop; Martin Lowe
Original assignee: Hattersley Newman Hender Ltd
Current assignee: Olympus Ormskirk Ltd
Priority date: 1996-05-02
Filing date: 1997-05-02
Publication date: 1997-11-05
Anticipated expiration: 2017-05-02
Also published as: GB9609190D0; GB2312731B; GB9708985D0

Abstract

A device for a valve for indicating the position of the valve closure member or obturator 20 comprises an indicator 11 which is profiled to slide axially within an indicator sleeve 7, but not rotate. Obturator 20 is moved by a handwheel 1 which causes the indicator 11 to move axially with reference to the main valve spindle in the same direction as the obturator 20. The indicator sleeve 7 defines a viewing window past which the indicator 11 slides. Graduations on the indicator 11 indicate, linearly, the position of the obturator 20. A stopmember 4 can be moved relative to the indicator so as to provide an adjustable stop for the indicator. The open position of the orbturator is determined by the position of the stop. The handwheel may be locked. is determined by the position of

Description

VALVE POSITION INDICATOR The present invention relates to a device for use with a valve for indicating the position of the valve closure member or obturator.

within building services applications, there exists a need to provide resistance to fluid flow at strategic positions within a pipework system in order to achieve distribution or 'balance' of flows to meet design criteria.

This balance is normally achieved by the use of flow measuring devices and/or adjustment of a profiled valve obturator to provide a specified resistance to flow (pressure drop).

For any given balancing valve, it is therefore necessary to be fully aware of the position of the obturator with reference to the valve seat.

A graduated scale is normally provided to show position of the valve, together with some form of 'memory stop mechanism' to allow re-setting of the valve to the same open position, whilst permitting full closure of the valve to shut off flow.

According to the present invention, there is provided a device for use with a valve for indicating the position of the obturator Of the valve comprising means for moving the obturator relative to the valve seat an indicator for indicating the position of the obturator relative to the valve seat, a stop member movable in relation to the indicator to provide a stop for the indicator whereby the obturator may be moved from a closed to an open position determined by the position of the stop member.

In a preferred embodiment of the invention the means for moving the obturator comprises a rotational member, advantageously a handwheel, which is connected to a valve spindle. This spindle is of the non-rising configuration, that is to say that the spindle does not move axially on rotation of the handwheel. The indicator is screwed into the handwheel and is disposed to slide axially within an indicator sleeve with no relative rotational movement between indicator and indicator sleeve. The indicator sleeve defines a viewing window and bears an axial datum mark. Rotation of the handwheel thus causes axial movement of the indicator relative to the valve spindle as the indicator sleeve is fixed rotationally. The indicator sleeve is adapted for location on a gland housing which forms part of the valve. The location profile of the housing is preferably hexagonal although other polygonal shapes may be used. This feature allows the installer to position the viewing window in the most advantageous position for a given installation. The indicator is graduated axially, one full turn of the handwheel causing an axial movement of one graduation of the indicator. An indicator ring which is graduated in tenths is connected to the handwheel. An axial datum on the indicator sleeve is provided to enable parts of the turn of the handwheel to be determined. The stop member comprises a lock ring which is operably connected to a drive shaft through intermeshihg gear forms on ring and shaft. Rotation of the shaft moves the lock ring axially to provide a variable position stop.

In order that the invention may be more clearly understood, embodiments thereof will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a cross-section of a valve with a device according to the invention, Figure 2 is a cross-section of part of the valve of figure 1 to an enlarged scale, Figure 3 is a side elevational view of the part of the valve shown in figure 1, but with modification, Figure 4 shows part of the valve of figure I with an alternative lock, and Figures 5, 6 and 7 show side, front and end elevational views respectively of part of the lock of figure 4.

Referring to the drawings, a handwheel 1 is attached via a spline detail to the main valve spindle 2. An obturator 20 is connected to the lower end of the spindle 2. This seats on a valve seat 21 to close off the valve and is spaced therefrom to open the valve to the desired degree of opening. The valve mechanism is of the non-rising spindle configuration and turning the handwheel 1 clockwise will close the obturator 20 and turning anti-clockwise will open the obturator 20.

The lower section of the handwheel 1 incorporates an internal left hand thread 3. A lock ring 4 is initially screwed in, as far as possible to the maximum 'depth' within the threaded portion. A drive shaft 5 with a hexagon and/or screwdriver slot, protruding from the top of the handwheel 1, is used to turn the lock ring 4 via intermeshing gear forms on both components.

Between the handwheel 1 and the valve bonnet 6 is positioned an indicator sleeve 7, complete with a viewing window 8 and an axial datum mark 9. The indicator sleeve 7 is located on a gland housing 10, the location profile of which is preferably hexagonal in shape. This feature allows the installer to position the viewing window 8 in the most advantageous position for a particular installation to improve visibility of scale.

Co-operating with the indicator sleeve 7 is an indicator 11 which is profiled to slide axially within the indicator sleeve 7 but not rotate. The top of the indicator sleeve 7 incorporates a portion of left hand thread which is screwed into the handwheel thread. Turning of the handwheel 1 therefore causes the indicator 11 to move axially with reference to the main valve spindle in the same direction as the obturator.

The surface of the indicator 11, that slides past the viewing window 8 has graduations that indicate, linearly, the position of the obturator 20 in 'number of turns open'. Each graduation represents one fuil turn of the handwheel. The viewing window incorporates an additional reference datum, normal to the spindle axis. The lower edge of the handwheel holds an indicator ring 12 that is graduated in 1/1 oaths, to indicate 'fractions of a turn' with reference to the axial datum 9 of the indicator sleeve 7. 'Zeroing' alignment of the 'turns' indicator 11 and the indicator ring 12 is initially achieved by location of the indicator 11 with reference to the viewing window datum and the shaft splines to locate the 'zero' of the indicator ring 12 with reference to the axial datum mark 9.

A typical mode of operating the device would be to fully open the valve anticlockwise. This operation would bring the indicator 11 in close proximity to the lock ring 4 already screwed to its initial position.

Following a normal commissioning procedure, the optimum position of the obturator is determined.

The lock ring 4 is then screwed down to a position in contact with the top face of the indicator 11 by turning the drive shaft 2.

This will prevent any further opening movement of the obturator 20 whilst allowing the obturator 20 to move to a closed position when required.

Once satisfied that the correct position has been obtained, a handwheel closure cap 13 is then fitted.

A locking mechanism is provided which can be activated from the top face of the handwheel. This consists of a spindle 15 with a semiformed spline feature which, when turned, locks on two gear forms one of the internal diameter of the lock ring 4 and a corresponding gear form on the lower part of the indicator 11. Once engaged, no rotation of either the lock ring 4 or the handwheel 11 is then possible.

A security locking indicator assembly 16 is also provided protruding through the top of the handwheel closure cap 13, and capable of accepting a padlock 17 to prevent the closure cap being removed.

An elastomer vapour seal 14 may be fitted as shown in figure 3 which allows a neat encapsulation of the valve within an insulation box to reduce heat loss and the effects of condensation.

The above described internal stop mechanism enables the opening of the valve to be restricted independently of the obturator movement and avoids additional penetration into the pressure envelope. The operating mechanism allows inclusion of a high integrity bolted gland arrangement.

The locking device prevents handwheel rotation in any desired position between full open and full closed. The security cap, the removal of which is prevented by inclusion of a padlock or lead/wire seal, thereby restricts access to the internal locking arrangement. An elastomeric collar fitted to the bonnet or operating/indicator mechanism allows the close connection of proprietary insulation boxes for vapour sealing.

Referring to figure 4, part of the valve of figure 1 is shown provided with an alternatlve lock to the assembly 16. This lock comprises a locking pin 30, a substantially Z-shaped member 31 and a padlock 32. The locking pin 30 extends through the spikes of the handwheel 1 and an aperture 33 formed in the Z-shaped member 31. This Z-shaped member 31 is fixed between the gland housing 10 and valve bonnet 6. The padlock 32 extends through an aperture 34 in the lower end of the locking pin 30 to lock the pin 30 to the member 31 and thus the handwheel 1 in position.

Claims

CL,AIMfi

1. A device for use with a valve for indicating the position of the obturator of the valve comprising means for moving the obturator relative to the valve seat an indicator for indicating the position of the obturator relative to the valve seat, a stop member movable in relation to the indicator to provide a stop for the indicator whereby the obturator may be moved from a closed to an open position determined by the position of the stop member.

2. A device as claimed in claim 1, in which the means for moving the obturator comprises a rotational member.

3. A device as claimed in claim 2, in which the rotational member is a handwheel.

4. A device as claimed in claim 3, in which the handwheel is connected to a valve spindle.

5. A device as claimed in claim 4, in which the spindle does not move axially on rotation of the handwheel.

6. A device as claimed in claim 5, in which the indicator is screwed into the handwheel and is disposed to slide axially within an indicator sleeve with no relative rotational movement between indicator and indicator sleeve.

7. A device as claimed in claim 6, in which the indicator sleeve defines a viewing window and bears an axial datum mark.

8. A device as claimed in claim 7, in which the indicator sleeve is fixed rotationally whereby rotation of the handwheel causes axial movement of the indicator relative to the valve spindle.

9. A device as claimed in claim 6, 7 or 8, in which the indicator sleeve is adapted for location on a gland housing which forms part of the valve.

10. A device as claimed in any of claims 3 to 9, in which the indicator is graduated axially.

11. A device as claimed in claim 10, in which one full turn of the handwheel causes an axial movement of one graduation of the indicator.

12. A device as claimed in claim 11, in which an indicator ring which is graduated is connected to the handwheel.

13. A device as claimed in claim 12, when appendant directly or indirectly to claim 6, in which an axial datum on the indicator sleeve is provided to enable parts of the turn of the handwheel to be determined.

14. A device as claimed in any preceding claim, in which the stop member comprises a lock ring which is operably connected to a drive shaft through intermeshing gear forms on ring and shaft.

15. A device as claimed in daim 14, in which rotation of the shaft moves the lock ring axially to provide a variable position stop.

16. A device as claimed in any preceding claim, in which locking means are provided for locking the means for moving the obturator in a selected position.

17. A device for use with a valve substantially as hereinbefore described with reference to figure 1 and 2 or to figures 1 and 2 with the modification shown in figure 3 or figures 4 to 7 of the accompanying drawings.