|1.||An obturating component for preventing unwanted flow of fluid is characterised by the provision of means (10) forming a signal path for incorporation in a signal system (11) whereby interference with the signal path as a result of wear may be detected.|
|2.||An obturating component as claimed in claim 1 comprising a valve seat (1) for cooperation with a valve member (5).|
|3.||An obturating component as claimed in claim 2 wherein the means (10) forming a signal path comprise means embedded close to the external surface (3) of the valve seat (1).|
|4.||An obturating component as claimed in claim 1 comprising a gasket (35).|
|5.||An obturating component as claimed in claim 1 comprising a valve member (2) for cooperation with a valve seat (1).|
|6.||An obturating component as claimed in any one of claims 1 to 5, wherein the means (10) forming a signal path comprise optical fibre means (12) connectable to a light source (13) and to a light receiver (14).|
|7.||An obturating component as claimed in any one of claims 1 to 5, wherein the means (10) forming a signal path comprise electrical or electronic signal conductor leads.|
|8.||An obturating component as claimed in any one of claims 1 to 5, wherein the means (10) forming a signal path comprise fluid pressure signal pipes.|
|9.||An obturating component as claimed in any one of claims 1 to 5, wherein the means (10) forming a signal path comprise ultrasonic signal paths.|
|10.||An obturating component as claimed in any one of claims 1 to 5, wherein the means (10) forming a signal path comprise more than one of the signal paths set forth in any of claims 6 to 9.|
This invention relates to fluid flow obturating components, and is particularly, but not exclusively, concerned with fluid flow obturating components for preventing unwanted flows, such as flow control valve seats and gaskets.
Taking a ball valve unit as an example, this comprises a ball-shaped valve member defining a through-flow duct, which cooperates with a cup-shaped seat, the valve member being rotatable about the seat between operative and inoperative positions.
The valve seat is often made of plastics material, which must remain pressure-tight throughout its life.
Seat wear, which may be caused by corrosion and/or erosion, inevitably occurs in due course, and such wearallows un¬ wanted flow of fluid to take place.
According to the present invention, an obturating component for preventing unwanted flow of fluid is provided with means forming a signal path for incorporation in a signal system, whereby interference with the signal path as a result of wear may be detected.
The signal path may conduct fluid, light, electronic, or electrical signals.
Embodiments of the invention will now be described by way of example only, with reference to the accompanyinσ drawings wherein :-
Figure 1 is a plan view of a seat for a ball valve unit, Figure 2 is a section, taken on the lines II-II of Fiqure 1,
Figure 3 is a fragmentary view in perspective, of part of the valve seat, together with a semi-diagrammatic illustration of a signal system,
Figure 4 is a side view, in medial section, of the ball valve members, and
Figure 5 is a fragmentary side view, partly in section, of flanged piping.
With reference to Figures 1, 2, 3 and 4, a pair of seats 1 for cooperation with a ball-shaped valve member 2 (Figure 4) in forming a ball valve unit 20 is shown, each seat 1 comprising a cup-shaped component of plastics material. The part-spherical seating surface of the valve seat 1 is shown at 3.
The ball-shaped valve member 2 is formed v/ith a through duct 4 and is rotated relative to the valve seats 1 by a lever- operated valve spindle 5. The valve unit has an inlet 6 and an outlet 7. Turning the valve spindle 5, and thus the valve member 2, through 90° moves the valve member from an operative to an inoperative position and thus terminates flow through the valve unit.
The valve seats 1 and valve member 2 serve as obturating components in preventing unwanted flow of fluid through the valve unit. The valve seats 1 form seals between the valve member 2 and valve unit housing 21 so as to prevent any fluid by-passing the valve member. The valve member 2 itself prevents flow from inlet 6 to outlet 7 when in an inoperative position.
As shown in Figure 3 , each valve seat 1 is provided with means 10 forming a signal path incorporated in a signal system 11, whereby interference with the signal path as a
result of wear may be detected.
The means 10 comprise a tortuously-disposed optical fibre 12 embedded close to surface 3, within the valve seat 1. One end of the fibre 12 is connected to a light source 13 and the other end to a light receiver 14. The signal system 11 comprises the fibre 12 , the light source 13 , light receiver 14, connections 15, 16, and alarm initiator 17 with a warning light 18.
In operation, the source 13 transmits light signals through the optical fibre 12 to be collected by the receiver 14. In the event that undue wear of the valve seat surface 3 has taken place, (whereby leakage past the valve member 2 will occur) , the wear will fracture or damage the optical fibre 12 sufficiently to interfere with the passage of light signals therethrough.
This interference will be sensed by the alarm initiator 17 whereby a visible warning signal will be emitted by the light 18.
With reference to Figure 5, a pair of pipes 30, 31 with co¬ operating flanges 32, 33 are shown clamped together by nuts and bolts (not shown) acting along lines 34.
A gasket 35 is clamped between the flanges 32, 33 by the action of the nuts and bolts. Optical fibres 12a_ are embedded in the gasket 35, adjacent the surfaces thereof.
The fibres 12a are connected to a signal system identical to system 11 (Figure 3) , interference with the system resulting from wear of the obturating gasket 35.
Modifications of the embodiments illustrated may include
the use of :-
1. Electrical or electronic signal conductor leads instead of optical fibres.
2. Small bore fluid pressure signal pipes instead of optical fibres.
3. Signal paths incorporated in the ball valve member instead of in the valve seat.
4. Ultrasonical signal paths.
5. Multiple signal paths,-which may comprise a mixture of the modifications listed above.
A further modification comprises one or more signal paths of circular shape. For example, incorporated in an obturating component in the form of a piston ring.
Obviously, the design of the signal system 11 may have to change to suit any of the above-mentioned modifications.