GB2406887A

GB2406887A - Locking coupling with fluid sensing.

Info

Publication number: GB2406887A
Application number: GB0322968A
Authority: GB
Inventors: John Franklin Weatherhead; Richard George Titchener
Original assignee: Tanker Solutions Ltd
Current assignee: Tanker Solutions Ltd
Priority date: 2003-10-01
Filing date: 2003-10-01
Publication date: 2005-04-13
Anticipated expiration: 2023-10-01
Also published as: GB2406887B; GB0322968D0

Abstract

A coupling arrangement 10 for use in fluid containing or conveying structures comprises a coupling 12 of two coupling elements 32, 34 e.g. of storz, instantaneous, Machino or NPSH type connected to pipe sections 36, 38 which has means for automatic locking of the coupling in response to a predetermined condition e.g. fluid presence by pressure, conductivity or colour inside the coupling to prevent the coupling from being uncoupled. A sensor 18 provides an electric actuation signal to a solenoid valve activator 20 to supply air from a line 22 to actuate air cylinder 14 locking means and prevents relative rotation of the parts of the coupling. The locking members may be biased to an unlock position in the absence of a signal and there may be visual indicators that the coupling is locked. Prevents release of pipe contents.

Description

COUPLING ARRANGEMENT

The present invention relates to a safety arrangement for a coupling and a safety coupling. The invention relates particularly, but not exclusively, to a safety coupling arrangement and a safety coupling for use in fluid containing or conveying structures such as vessels, containers, conduits and pipes.

Fluid containing or conveying structures such as vessels, containers, conduits and pipes can be used to contain or convey hazardous substances. Also, during such use these structures can be pressurized. Conventional coupling arrangements for use in these structures, such as the widely used Store coupling, can be disconnected or undone accidentally whilst the hazardous substance is present or being conveyed through the coupling arrangement or when hazardous operating conditions exist inside the arrangement. This can result in serious injuries to the operator or bystanders and can also result in spillages which may be environmentally damaging.

Within the context of this application, where it is referred to a fluid conveying or fluid containing structure, the fluid may comprise gaseous, liquid or solid flowable substances or combinations thereof.

To improve the safety of conventional coupling arrangments, mechanical locking devices have been widely applied. These devices provide a manual lock which is applied over the coupling or which forms part of it. The coupling cannot be undone without releasing the locking device. However, these locking devices can still be undone whilst hazardous conditions exist inside the coupling, and, consequently, the coupling can be undone in those conditions. Therefore, these locking devices do not offer adequate protection to prevent accidents.

The present invention provides an improved coupling arrangement and a structure for conveying and conducting fluids comprising an improved coupling arrangement as defined in any of the accompanying claims.

In an embodiment of the invention, there is provided a coupling arrangement comprising an automatic locking arrangement which locks the coupling in response to a pre- determined condition inside the coupling arrangement to prevent the coupling from being undone.

In this way, the coupling is prevented from being uncoupled accidentally when a hazardous condition is present inside the coupling such as when the coupling is pressurized, or hazardous substances are conveyed through the coupling.

In a preferred embodiment of the invention, the coupling arrangement for use in fluid containing or fluid conveying structures comprises a releasable coupling, wherein the arrangement comprises a sensor for sensing a condition inside the arrangement or structure; means for locking the coupling to prevent the coupling from being released, and; an activator for activating the locking means in response to the sensed condition to provide automatic locking of the coupling.

The sensor may sense the presence of a substance inside the arrangement or structure such as vessel, coupling, pipe or conduit by sensing a pressure and/or conductivity and/or colour or other parameter of the fluid or substance inside the arrangement or structure. In response to the sensed condition, the activator automatically activates the locking means which causes the coupling to be locked so that it cannot be released or uncoupled.

Preferably, the arrangement comprises means for triggering activation of the locking means if the sensed condition corresponds to a pre-determined condition.

The sensor may comprise the trigger means. For example, the sensor may be configured such that the sensor provides an activation signal to the activator if the sensed condition such as pressure corresponds to a predetermined condition.

Also, the sensor may sense a pressure or other condition inside the arrangement or structure which exceeds a threshold value. In that case the activator activates the locking means.

In one embodiment of the invention, the locking means are operated by the pressure of the substance that is conveyed through the coupling arrangement. A conduit connects the inside of the coupling arrangement or structure directly to the locking means so that the presence of the substance automatically activates the locking means as part of the substance is conveyed through the conduit. The locking means may comprise trigger means. The trigger means may be in the form of means for biasing the locking means in an unlocked position, the bias being overcome by the pressure as provided by the conduit for operating the locking means.

In this embodiment, the conduit forms both the activator and the sensor to operate and activate the locking means.

In this way, an inherently safe coupling arrangement is provided whereby the presence of a substance inside the conduit activates the locking mechanism of the coupling to prevent the coupling from accidentally being undone. This prevents personal injuries and greatly improves the safety aspects of conventional couplings.

In a further embodiment, the locking means are powered directly by the fluid inside the coupling arrangement or structure. This provides an inherently safe coupling arrangement which is automatically activated when a pressurized fluid is present.

In another embodiment of the invention, the condition sensor provides an activation signal. The sensor may be a pressure sensor to detect a predetermined pressure level, a conductivity sensor to detect the presence of a substance in the coupling such as a liquid or a gas, or any other suitable sensor for sensing a fluid conveyed through the coupling or the characteristics of the fluid conveyed through the coupling or structure.

In another embodiment of the invention, the arrangement comprises a power supply for powering the locking means, the activator comprising a switch for switching the power supply to power the locking means. The locking means are preferably powered by a pressurized fluid such as a hydraulic fluid, compressed air. Alternatively or additionally, the locking means may be powered by electicity. The activator switches the power supply to the locking means to activate the locking means. In this way, the sensor and activator operate independently from the power supply to the locking means which allows the sensor and activator to be overridden in case it is desirable to operate the locking means independently from the sensed condition inside the coupling arrangement or structure.

In an embodiment, the locking means comprise one or more locking members and means for moving the locking members into a locking position. The moving means preferably comprises an expendable member in the form of an air powered or hydraulic cylinder which operates one or more locking members. The moving means may also comprise an electrical member such as a coil and associated magnet element for moving the locking member in the desired position.

The moving means may be powered by a suitable power supply.

The activator may switch the power supply to the moving means to activate and engage the locking means in response to the activation signal.

Preferably, the moving means comprises an air powered cylinder and the activator comprises a solenoid valve for switching compressed air to the cylinder. The solenoid valve is activated or switched by an activation signal from the condition sensor. This sensor is preferably a pressure sensor as these sensors are effective for a wide range of fluids and operating conditions. The activation signal is an electrical signal and the solenoid valve is operated electrically.

The sensor may further comprise a gas sensor, colour sensor, vibration sensor, proximity sensor or any other

suitable sensor.

As the valve and sensor are electrically connected, the sensor and the valve may each be located in any desired position in relation to the coupling. The sensor may be located in the direct vicinity of the coupling or inside the coupling. Alternatively, the sensor may be located on any part of the fluid conveying or containing structure.

The sensor may also be in the form of a control element such as a control switch or button or over-ride button which is located remotely from the structure or coupling to control the locking means remotely, for example by a second operator.

The locking means may comprise a first indicator to indicate whether the locking means have been activated. The first indicator is preferably provided on or in relation to the moving means to indicate activation of the moving means.

In an embodiment, the coupling comprises at least two co- operating coupling elements. The locking means may comprise one or more locking members, the locking members being provided on a first coupling element. The locking means may comprise at least one locking member provided on a first coupling element. A further coupling element may be adapted to receive the locking member. In a preferred embodiment, the further coupling element comprises an aperture for receiving the locking member. The further coupling element may also comprise a blanking cap which is adapted to close off the coupling.

When the locking means are activated and the locking members of one coupling element engage with a further coupling element, the coupling elements are prevented from twisting or rotating relative to one another. This prevents most conventional couplings from being undone.

Particularly, the popular Storz coupling which relies on a twisting action to inter-connect and disconnect the coupling elements can be prevented from being coupled.

The locking means and locking members may be configured in a suitable configuration to allow the locking means to be applied to a wide variety of conventional couplings.

The locking means and the locking members may comprise a second indicator for indicating the position of the locking member relative to a coupling element. This provides the user with an indication that the locking members are engaging (locked) or are in a non-engaging position (unlocked).

In a further embodiment of the invention, the locking member may comprise a second indicator which engages with the further coupling element when the locking member is in the locked position. The further coupling element may comprise a recess for receiving the second indicator. As the second indicator travels across to the second coupling element, it is immediate clear to the operator or user of the coupling that the coupling is locked.

The further coupling element may comprise a further recess which provides access to the locking member from outside the coupling elements. This allows manual unlocking of the coupling in case the locking means are malfunctioning.

Preferably, the coupling is unlocked by means of a special tool to prevent accidental uncoupling when hazardous conditions are present in the coupling.

In another embodiment of the invention, the locking member is activated by means of a reciprocating expendable member such as an air cylinder which is operated by a pressurised fluid such as air or an hydraulic fluid.

Alternatively, the locking members may be activated by means of an expandable seal which is provided at or near the locking member and which upon expansion allows the locking member to protrude from the first coupling element and to engage with a further coupling element.

The pressurized fluid for activating the coupling may be provided by a pressurized fluid supply such as a compressor, or the braking supply or air suspension of a heavy goods vehicle. For multiple coupling arrangements, a single air supply may be provided which is fed either along the hose from one coupling to the next by adding a small bore pipe to the hose or adding the small bore pipe in the wall of the hose during manufacture. A suitable indicator may be added to the air line feeding the air to the locking member that shows that there is pressure in that line thus also indicating that locking member is in a locked or unlocked position.

The coupling arrangement may be applied to any facility in which hazardous substances are stored, conveyed or otherwise present.

In yet another embodiment of the invention, the coupling arrangement may comprise an additional condition sensor, the additional condition sensor providing a back-up to the first condition sensor in case this sensor fails for whatever reason. In addition, the additional sensor may comprise different sensing characteristics from the first condition sensor. For example, the first condition sensor may comprise a pressure sensor whereas the second condition sensor may comprise a conductivity sensor.

The additional condition sensor may comprise a visual warning or audible alarm to indicate that the first condition sensor and/or the second condition sensor is malfunctioning.

In yet another embodiment of the invention, there is provided a fluid conveying or containing structure comprising one or more coupling arrangements as herein before described. The structure may comprise monitoring means for monitoring the coupling arrangements.

In a further embodiment, the storage facility may comprise a pressure gauge, the activation means being connected to the pressure gauge. This has the advantage that it provides a dual safety system, which prevents the coupling from being uncoupled when pressure is present in the facility.

The condition sensor may be remotely monitored by a hard wire link or by a remote, wireless link. The condition sensor may be monitored on a panel which is visible to an operator or controller of the facility. The sensor means and/or activating means may be remotely operated by an operator to allow the couplings to be locked or uncoupled if desired.

The pre-determined condition which is sensed and which enables the locking means to be activated may be pre-set by direct adjustment of the condition sensor. Alternatively or in addition, the arrangement may comprise a controller for enabling the operator to pre-set the desired pre-determined condition.

In yet another embodiment of the invention, there is provided a coupling arrangement and/or a coupling element and/or a coupling as herein before described.

According to the various aspects of the invention, there is provided an automatic safety coupling arrangement for hoses, supply lines and other conduits which cannot be undone whilst a pre-determined condition exists within the supply line which poses a risk to the health and safety of operators, bystanders or the environment.

Although the safety coupling arrangement is suitable for use in fluid conveying and containing structures, an arrangement similar to the coupling arrangement may also be applied on safety covers, safety valves and other equipment to prevent access to storage facilities which contain hazardous and/or pressurized substances in conditions that are hazardous to the operator. These arrangements may comprise a means for locking the cover or facility and means for activating the locking means in response to a sensed condition inside the facility to prevent the facility from being accessible. The activating means may comprise a suitable sensor for sensing the condition. The arrangement may further comprise a trigger for triggering activation of the locking mechanism if the sensed condition corresponds to a pre-determined condition.

In an embodiment of the invention, there is provided a safety cover arrangement for use in fluid containing or fluid conveying structures comprising a releasable cover, wherein the arrangement comprises a sensor for sensing a condition inside the arrangement or structure; means for locking the cover to prevent the cover from being released, and; an activator for activating the locking means in response to the sensed condition to provide automatic locking of the cover.

From the aforesaid disclosure, it is clear that the coupling arrangement can be applied to any suitable coupling and is not necessarily limited to twist engagable couplings such as Storz couplings. Preferably, the automatic activation means comprises a visual indicator which allows the operative to see immediately whether the locking means are engaged or disengaged.

Embodiments of the invention will now be described by way of example only and with reference to the accompanying illustrative drawings in which: Figure 1 presents a diagrammatic side view of a coupling arrangement according to an embodiment of the invention; Figure 2 presents a diagrammatic cross-sectional view of the coupling arrangement of Figure 1; and Figure 3 presents a diagrammatic side view of a coupling arrangement according to an alternative embodiment of the invention.

The coupling arrangement 10 comprises a coupling 12. The coupling 12 comprises two coupling elements 32, 34 which are each connected to a pipe section 36, 38. The coupling elements 32, 34 are of a so-called Storz type which engage and disengage by means of a twisting action. However, the coupling arrangement 10 as herein described can be applied to any type of coupling such as an instantaneous-type coupling, a Machino-type coupling or a NPSH type coupling.

The arrangement 10 comprises a sensor 18 in the form of a pressure sensor 19 for sensing a pressure inside the coupling 12, means 14 for locking the coupling to prevent the coupling from being released, and an activator 20 for activating the locking means 14 in response to the sensed condition to provide automatic locking of the coupling 12.

The pressure sensor 19 is powered by an electric power supply 28 and the sensor 19 provides an electric activation signal 30 to he activator 20. I'he activator 20 is a solenoid valve or switch which is adapted to switch compressed air 22 to the locking means 14 via air supply lines 24.

The locking means 14 comprises reciprocating expendable members for moving the locking means 14 in a locked position. The expendable members comprise air cylinders 42, 44 with movable pistons 46, 48. The pistons 46, 48 form locking members 57,59. The locking members 57 59 are adapted to extend to prevent the twisting action of the coupling elements 32, 34 relative to one another to prevent the coupling 10 from being uncoupled.

The locking members 57,59 do not engage with the opposite coupling element 34, but merely prevent: the opposite coupl:TIy element 34 from rotating relative t., file other coupling element 32 to prevent the coupling from being uncoupled. Therefore, the opposite coupling element 34 is unmodified.

The user is advised of the position of the locking members 57,59 by two separate visual indicators 26,54,56. The first indicator 26 is provided in the airline 24 and indicates whether the line its pressurized or unpressr:i.sed. In addition, the locking members, 57,59 each comprise additional visual indicators in the form of flags 54, 56 which extend from the locking members 57,59 and which are visible from outside the coupling 12 to indicate the 0 position of the locking members 57,59. I'h.e visual indicators 54, 56 are each slideably arranged in a recess.

The locking members 57,59 are resiliently biased in an unlocked position in the absence of pressure in the air line 24. This allows the coupling to be disengageable when no pressure is sensed by the sensor 18.

In use, the coupling elements 32, 34 are coupled together by means of a twist action to provide an inter-connected coupling 12. As no pressure is present in the coupling 12, the locking members 46, 48 are not engaged. As a pressurized fluid is conveyed through the pipes 36, 38 and coupling 12, the pressure sensor 19 activates the solenoid valve 40 and this activates the air cylinders 42, 44 and associated locking members 46, 48 so that these extend and prevent the coupling 12 from being undone.

As the pressure in the system is removed or reduced below the predetermined level or condition, this is detected by the pressure sensor 19 which causes the solenoid valve to release the air pressure to the locking members 57,59 and which consequently allows the locking members 57,59 to withdraw. This allows the coupling 12 to be undone by a twisting action.

Figure 3 prevents an alternative coupling arrangement 100 which is largely similar to the coupling arrangement of Figures 1 and 2.

The coupling arrangement 100 comprises a coupling 112. The coupling 112 comprises two coupling elements 132, 134 which are each connected to a pipe section 136, 138.

The arrangement 100 comprises a sensor 118 in the form of a pressure sensor 119 for sensing a pressure inside the coupling 112, means 114 for locking the coupling to prevent the coupling from being released, and an activator 120 for activating the locking means 114 in response to the sensed condition to provide automatic locking of the coupling 112.

The pressure sensor 119 is powered by an electric power supply 128 and the sensor 119 provides an electric activation signal 130 to the activator 120. The activator is adapted to switch compressed air 122 to the locking means 114 via air supply lines 124 similar to the arrangement as shown in Figures 1 and 2.

The locking means 114 comprises air cylinders 142, 144 with movable pistons 146, 148. The pistons 146, 148 form locking members. The pistons 146,148 are adapted to extend to prevent the twisting action of the coupling elements 132, 134 relative to one another to prevent the coupling 100 from being uncoupled.

The pistons 146,148 comprise visual indicators 154,156 which travel across to the opposite coupling element 134 when the coupling is locked. The coupling element 134 comprises recesses 160, 162 for receiving the indicators 154,156. In this way, it is immediately visible to the user when the coupling is in a locked position and unlocked position.

The locking members are resiliently biased in an unlocked position in the absence of pressure in the air line 124.

This allows the coupling to be disengageable when no pressure is sensed by the sensor 118. The coupling element 134 comprises additional recesses 164,166 which allow an operator to manually unlock the coupling 112 by moving the pistons 146,148 into the unlocked position. This is useful in case the locking means 114 malfunction.

In use, similar to the coupling 10 of Figures 1 and 2, the coupling elements 132, 134 are coupled together by means of a twist action to provide an inter-connected coupling 112.

As no pressure is present in the coupling 112, the locking members 146, 148 are not engaged. As a pressurised fluid is conveyed through the pipes 136, 138 and coupling 112, the air cylinders 142, 144 and associated pistons 146, 148 are activated so that these extend and prevent the coupling 112 from being undone.

As the pressure in the system is removed or reduced below the predetermined level or condition, this is detected by the pressure sensor 119 which causes the activator 140 to release the air pressure to the locking members and which consequently allows the pistons 146,148 and associated locking members to withdraw. This allows the coupling 112 to be undone by a twisting action.

It is evident that the coupling arrangement as herein before described has a wide range of applications and can also be applied to secure facilities to prevent accidental access to dangerous substances and dangerous operating conditions.

Claims

1. A coupling arrangement for use in fluid containing or fluid conveying structures comprising a releasable coupling, wherein the arrangement comprises a sensor for sensing a condition inside the arrangement or structure; means for locking the coupling to prevent the coupling from being released, and; an activator for activating the locking means in response to the sensed condition to provide automatic locking of the coupling.

2. An arrangement according to claim 1, wherein the arrangement comprises means for triggering activation of the locking means if the sensed condition corresponds to a pre-determined condition.

3. An arrangement according to claim 2, wherein the sensor means comprises the trigger means.

4. An arrangement according to claim 2 or 3, wherein the locking means comprises the trigger means.

5. An arrangement according to any of the preceding claims, wherein the arrangement comprises a conduit, the conduit interconnecting the inside of the arrangement or structure and the locking means to sense the condition inside the arrangement or structure and to activate the locking means.

6. An arrangement according to any of the preceding claims, wherein the condition sensor comprises a pressure detector and/or a conductivity sensor.

7. An arrangement according to any of the preceding claims, wherein the activator comprises a first indicator for indicating activation of the locking means.

8. An arrangement according to any of the preceding claims, wherein the arrangement comprises a power supply for powering the locking means, the activator comprising a switch for switching the power supply to power the locking means.

9. An arrangement according to any of the preceding claims, wherein the locking means comprises one or more locking members and means for moving the locking members into a locking position.

10. An arrangement according to claim 9, wherein the moving means comprises an expendable member.

11. An arrangement according to claim 9 or 10, wherein the locking members are biased in an unlocked position in the absence of the sensed condition.

12. An arrangement according to any of claims 9 to 11, wherein the moving means is powered by electricity and/or a pressurised fluid.

13. An arrangement according to any of claims 9 to 12, wherein the coupling comprises at least two co-operating coupling elements.

14. An arrangement according to claim 13, wherein the locking means prevent the coupling elements from rotating relative to one another such that the coupling can be undone.

15. An arrangement according to claim 13 or 14, wherein the locking members are provided on a first coupling element.

16. An arrangement according to claim 15, wherein a further coupling element comprises one or more apertures for receiving the locking members.

17. An arrangement according to any of claims 13 to 16, wherein the locking member comprises a second indicator for indicating the position of the locking member.

18. An arrangement according to claim 17, wherein the second indicator engages with the further coupling element when the locking member is in the locked position.

19. An arrangement according to claim 18, wherein the further coupling element comprises a recess for receiving the second indicator.

20. A coupling or a coupling element for use in a coupling arrangement according to any of the preceding claims.

21. A fluid conveying or containing structure comprising one or more coupling arrangements according to any of claims 1 to 19.

22. A structure according to claim 21, wherein the structure comprises means for monitoring the coupling arrangement.

23. A structure according to claim 21 or 22, wherein the structure comprises means for controlling the coupling arrangement. - 1 9

24. A coupling arrangement and a structure as shown in any of the accompanying drawings and as herein before described.