NZ243346A - Connecting the right pipe to the right tank; testing electrical continuity - Google Patents

Description

243346 Patents Form 5 Priority Date(s): Complete Specification Filed: Publication Date: .?..Z..f£B...199$ P.O. Journal No: N.Z. No.

NEW ZEALAND Patents Act 1953 COMPLETE SPECIFICATION A SYSTEM/APPARATUS FOR INDICATING ELECTRICAL CONTINUITY OF FLUID CARRYING COMPONENTS q J >nC° ' Aas"-"** We, LIQUIP SALES PTY LIMITED, an-Australion company^ of 13 Hume Road, Smithfield, New South Wales 2164, Australia do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- p ©V n A 'ft/ - 1 - (Followed by 1A) ^ ^ JUL1992 24334 " 1 f\- A System/Apparatus for Indicating Electrical Continuity of Fluid Carrying Components The present invention is particularly relevant to chemical storage systems.

Typically, a chemical storage facility stores chemicals in suitable tanks which are filled and emptied through a network of pipes. If mobile tankers are used to distribute fluids from manufacturing centres to end users or to intermediate storage, typically, such mobile 10 tanks must comprise several compartments each designed for different products; an example of this is the distribution of petroleum products by road tanker to a service station, the latter also having several tanks.

To protect the quality of product and for safety 15 reasons, it is of great importance that intermixing of products is prevented.

Therefore, it is essential that the person who is emptying or filling a compartment of a road tanker, knows which product is loaded into which compartment of 20 the tanker at the central terminal of the distribution system and in addition, knows and can identify which tank at the end user or secondary storage is to receive the product and ensures the hose used for transfer is correctly connected to the tanker and the receiving site. 25 Common systems in use to help prevent mixing of products due to incorrect connections or incorrect identification include bills of lading (paperwork), product name tags, colour codes and sight glasses to provide visual reminders. The systems however, are often 30 insufficient as accidents occur on a regular basis and wrong products are filled into wrong compartments or tanks.

According to the present invention there is provided a system for indicating electrical continuity of electrically conductive parts, comprising 35 an apparatus for measuring impedance of electrically conductive paths, a display for indicating whether an electrically conductive path has a predetermined imped an^faplfiiaftVpf conduits each for transferral of a respective fluid product from a first end tcp*second end, vflwein each II y , T u • conduit comprises a respective electrically conductive path havin| a ^fespective predetermined impedance. 243346 Preferably, each conduit comprises a first and second conduit path which are connectable together via an interconnecting conduit. Preferably the interconnecting conduit is connectable and disconnectable from each conduit part so as to make or break each conduits electrically conductive path.

Preferably a part of each conduit is provided with a component which provides the predetermined impedance. Predetermined impedance is preferably provided by a resistance.

Preferably, components of each conduit comprise electrically conductive sub-paths. Each conduit preferably comprises part of a pipeline which is connected with a reservoir for holding fluid product. The reservoir may be a stationary reservoir and/or a reservoir on a mobile tanker. The interconnecting conduit preferably comprises a hose.

The electrically conductive path further preferably comprises an electrically conductive cable or wire. The path is also preferably connected to an earth. The apparatus is preferably connected to opposite ends of each electrically conductive path.

The apparatus may be located in a control station permanently connected with at least one end of each electrically conductive path.

The first conduit part preferably comprises a stationary pipeline and the other conduit part may be provided on a mobile tanker. The apparatus may be provided on a mobile tanker.

In a preferred embodiment, the apparatus is arranged to control actuation of valves associated with each conduit when a container associated with one conduit is detected as having an expected predetermined impedance. 243346 Preferred embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 shows a system for monitoring electrical 10 continuity of components forming a pipeline network; and Figure 2 shows an electrical circuit diagram of a pipeline network when connected to a tanker having an apparatus for monitoring electrical continuity.

Referring to figure 1, the system shown therein 15 comprises 3 pipelines 11, 12 and 13 which are each electrically connected through cabling 14 to an earth. Each pipeline has a pipe fitting 11a, 12a and 13a of a predetermined resistance. The outboard end of each of these pipeline fittings is arranged to be connected with 20 a flexible hose 15 through hose flange 16. The other end of the hose 15 has a hose flange 17 which is arranged to be connected with an outlet of the mobile tanker 18.

The mobile tanker 18 comprises 3 tanks 19, 20 and 21 each having an outlet 19a, 20a and 21a comprising 25 an insulated joint 22 and a remote operated valve 23.

An apparatus for indicating electrical continuity is provided on the mobile tanker and is indicated by reference numeral 24. The apparatus 24 comprises a detector which in figure 1 is shown connected 30 through wire 25 to a point on ground line 14. A signal generator of the apparatus is connected to each of the outlets 19a, 20a and 21a by virtue of lines 26, 27 and 28 and the remote operated valves are each connected to a controller of the apparatus by cabling 29, 30 and 31. 35 In figure 2, the apparatus 24 is shgsgjsia^ying 3 separate controllers 32, 33 and 34 whircii are^/Sach arranged to comprise a signal generator a switcfu^tg means for actuating the valves 23. | \C> , <<* r>// '« 243 As shown in figure 2, the pipeline network is effectively capable of forming a number of electrical paths, such as path 1 which is formed by cable 26, hose 15, resistance R1 and pipeline 11; path 2 which is formed by cable 27, 5 hose 15, resistance R2 and pipeline 12; path 3 which is formed by cable 28, hose 15, resistance R3 and pipeline 13; path 4 which is formed by cable 26, hose 15, resistance R2 and pipeline 12; path 5 which is formed by cable 26, hose 15, resistance R3 and pipeline 13; path 6 10 which is formed by cable 27, hose 15, resistance Rl, pipeline 11; path 7 which is formed by cable 27, hose 15, resistance R3 and pipeline 13; path 8 which is formed by cable 28, hose 15, resistance Rl and pipeline 11; and path 9 which is formed by cable 28, hose 15, resistance 15 R2 and pipeline 12.

In the figures shown, the apparatus is connected to a point on earth cable 14 but could equally be connected to one of the pipelines or resistances.

Each of the paths defined above, although having 20 the ability to be electrically conductive, will not conduct electricity unless the hose 15 is connected at one end to either of cables 26, 27 and 28 and at the other end to either of resistances Rl, R2 and R3. Thus, a test signal which is sent by controller 32 will be 25 detected by the detector of controller 32 after having travelled through hose 15 through one of the resistances Rl, R2 or R3, through one of the pipelines 11, 12 or 13 and through the earth cable 14 for detection by the detector.

If it is desired to fill tank 18 of the mobile tanker with the contents of whatever is connected with pipeline 11, hose 15 must be connected at one end to pipe fitting 11a and at the other end to outlet 26. A test signal sent by controller 32 will then pass along path 1 35 along cable 14 and will be detected by the dete^toi^of 32 V * ' « A/ /V and the resistance of that path will be Rl. yAja indica£8 of the apparatus 24 will then show that ths'^hose 15 : been connected correctly as the resistance ^e^qAtected ^9Sy sf'VtO 2433 correct.

If by accident the hose 15 is connected at one end to outlet 19a and at the other end to pipe fitting 12a, a test signal generated by the controller 32 will 5 pass along path 4 through cable 14 and will be once again detected by the detector of controller 32. The resistance of path 4 however, will be R2 and the indicator of apparatus 24 will show that a wrong connection has been made as the resistance should be Rl. 10 Similarly, if the hose 15 is accidentally connected to pipe fitting 13a instead of pipe fitting 11a, the resistance detected would be R3 instead of Rl again indicating that a wrong connection had been made.

The advantage of the system described above is 15 that in addition to ensuring that the contents of a reservoir connected to a pipeline are transferred to the correct tank of a mobile tanker or alternatively, the contents of a tanker are transferred to the correct reservoir through its connecting pipework, electrical 20 continuity of each of the paths formed by the above described components can be checked continuously or at regular intervals to ensure that all components are grounded, this is particularly important when the fluid being transferred is particularly volatile and 25 susceptible to explosion through static electricity build up.

The system described above can be modified so that the system can monitor the electrical continuity of a pipeline network having electrical conductive paths 30 which are not necessarily formed by mobile tankers, for example, the mobile tanker 18 could in fact be a fixed installation and the flexible hose 15 could be replaced by an appropriate valve network so that a particular pipeline can be connected to a desired outlet by 35 operation of appropriate valves. The apparatus - 24 -could then ensure that the appropriate valves are /operated f; ensure that electrical continuity is always /piaintained that there is no possibility of static elec 243 up on any of the pipeline network components such as the pipeline tanks, valves etc.

A preferred operation or sequence will now be described by way of example only.

The following describes those operations pertinent to the invention and does not preclude the later addition of other features or operations.

A transportable tank arrives at the loading station at a fuel terminal to receive a load. Typically 10 the loading station has several flexible members each of which can be connected to any of several entry valves to the several compartments of the tank. it is standard safety practice for the first operation to be to connect the metal body of the 15 transportable tank to a known earth point on the loading station to dissipate any electrical charges. This earthing connection is of essentially negligible resistance.

Each flexible member is also connected to earth 20 and is electrically continuous through to the outboard valve connection with essentially zero resistance.

Now, for the purpose of this invention, each of the flexible loading members is provided with a joint in its outboard section, this joint having an accurately 25 known resistance with its value varying according to the product in that member.

A device on-board the vehicle can now use the electrical loop so formed to measure the resistance of each loop as the flexible member is connected to each 30 valve on the vehicle and so identify the product.

It may also visually indicate such product for use of persons present and record same on-board the vehicle.

As more than one loading operation can take 35 place at the same time (ie 2 or more flexible members may be connected to the vehicle) it is also /necessaryto electrically isolate each outboard valvef^of each p%)e from each compartment of the tanker. 2433 7- Electrical continuity is then established between each outboard valve separately from each other to. the measuring device on-board the vehicle: thus the measuring device can distinguish and record which product 5 was loaded into each compartment.

Should the system be incorrectly connected, for example the earthing cable is not connected, the measuring device will detect incorrect resistance values and prevent loading of any product by, for example 10 holding on-board valves closed.

Thus the on-board device has stored information on which compartments of the tank hold which products.

The vehicle is then driven to its destination(s) to discharge its load.

' Discharging is essentially the same in principle as loading. The tanker arrives with various products in its several compartments. A flexible member is used to connect any of the vehicle compartments to any of several receiving tanks.

For the purpose of this invention, each of the inboard ends of the several receiving tanks pipework is electrically bonded together to a common point with essentially negligible resistance. However each outboard end, to which the flexible member attaches, is separated 25 from its pipe by a joint with a known electrical resistance set according to the product kept in that tank and pipe.

The vehicle body is then connected to the common earth point to dissipate any electrical charges and 30 provide a continuous negligible resistance loop to each and every receiving tank.

The flexible member is connected at one end to a particular discharge valve on the vehicle. The on-board device, having stored the information at the loading 35 station, then identifies which product is in that compartment to which the flexible member isx The flexible member, for safe electrically conductive and has essent: 2433 8- resistance.

The other end of the flexible member is then connected to a chosen receiving point of one of the several tanks. This action completes an electrical loop 5 having a given resistance which the on-board device measures. The on-board device also compares this measurement with its stored knowledge of what the product is in that compartment of the vehicle. If the values match, then the receiving tank contains the same product 10 and the device will allow valves to open to commence discharge. If the values do not match, the device will prevent discharge and various messages or warnings can be produced to alert the operator.

If values do not match, the reason may be a 15 connection to a different product or a loss in good electrical continuity. The device may also detail whether the problem is "operational" (wrong product) or "safety" (poor electrical continuity).

As noted, other devices may be integrated with 20 the system. For example, the on-board device needs its memory "cleared" after every load ready to accept its new record. This can be done automatically by having liquid detectors in the bottom every vehicle compartment. When the sensor detects that the compartment is empty, it 25 can signal the vehicle device to clear that compartment memory ready for its next load.

Also for loading points not equipped with automatic identification, the onboard device may be such that it can be set manually after loading and so still 30 provide protection when unloading.

A further variant is to use the invention only as a safety device to ensure electrical continuity between all connections. In this variant, essential features are the same but varying values are set to 35 essentially zero resistance. Thus the devicas*e£»aks for . Kyf-vV electrical continuxty but does not distinguish between products. 243 An important advantage of the present invention as described in the preferred embodiment lies in the use of specific values of resistance in the circuits formed by the various electrical parts 1, 2 and 3. Each of the resistors Rl, R2 and R3 are chosen to indicate particular 10 products which that particular pipe line is to carry. This type of system is particularly suited to mobile tankers. This is because the specific value of the impedance shown in figure 2 by Rl, R2 and R3 can be measured by the apparatus 24. The apparatus identifies 15 the particular impedance or resistance measured with a particular electrical path and hence a particular pipeline. Without the specific resistances being associated or embedded somewhere in each pipeline there would be no clear way of distinguishing between the 20 pipelines carrying the various products. This being because the pipelines would normally have a similar resistance value.

It follows therefore that when a tanker is connected to one of the pipelines by the hose 15, the 25 apparatus 24 can monitor the product specific resistor value in the stationary pipeline 11, 12 or 13 and can change the product identification on the mobile pipeline (hose 15) or check that the resistance on the stationary pipeline corresponds to the product currently assigned to 30 the mobile pipeline connected to it.

This facility for updating means that on the side of the stationary pipelines there is a common return wire 14 which may be connected to the apparatus by cable . Because each of the stationary pipelines are earthed, there is no requirement for the stationary pipelines to be insulated in the same way tha€? thg^obile /r pipeline is insulated. It is prefaced that»\the II H stationary pipeline has a resistor embeddfec|p in the endjlas 2433 referenced by items 11a, 12a and 13a so that the joint between the stationary pipeline and the mobile pipeline is not insulated. Typically the resistance is very low between 100 to 680 ohms.

The embodiment described above is particularly useful for mobile tankers because a controller in the form of apparatus 24 can be installed in the cabin of the tanker and by merely connecting a cable 25 to the return line 14 the apparatus 24 can be used to ensure that the 10 correct product is attached via the hose 15 to the applicable stationary pipeline.

Claims (19)

243346 " 11 " WHAT-WE CLAIM IS:

1. A system for indicating electrical continuity of electrically conductive parts, comprising an apparatus for measuring impedance of electrically conductive paths, 5 a display for indicating whether an electrically conductive path has a predetermined impedance, a plurality of conduits each for transferral of a respective fluid product from a first end to a second end, wherein each conduit comprises a respective electrically 10 conductive path having a respective predetermined impedance.

2. A system as claimed in claim 1 wherein each conduit comprises a first and second conduit part connectable together via an interconnecting conduit.

3. A system according to claim 1 or claim 2 wherein 15 the interc mnecting conduit may be connectable and . disconnectable from each conduit part so as to make or break each conduits electrically conductive path.

4. A system as claimed in any one of the preceding claims wherein any part of each conduit is provided with 20 a component having the predetermined impedance.

5. A system as claimed in claim 4 wherein the predetermined impedance is provided by a resistance.

6. A system as claimed in any one of the preceding claims wherein components of each conduit comprise 25 electrically conductive sub-paths.

7. A system as claimed in claim 2 wherein each conduit includes a reservoir which is connected to one of the conduit parts.

8. A system as claimed in any one of the preceding 30 claims wherein each conduit comprises part of a pipeline.

9 A system as claimed in claim 2 wherein one of the conduit parts is connected to a reservoir on a mobile tanker.

10. A system as claimed in claim 9 wherein ^the 35 interconnecting conduit comprises a. hose.

11. A system as claimed in claim 6 electrically conductive path comprises an conductive cable or wire. n * > 24334 - 12-

12. A system as claimed in any one of the preceding claims wherein each electrically conductive path is connected to an earth terminal.

13. A system as claimed in claim 12 5 wherein the apparatus is connected to an iearth- which is common to each electrically conductive path.

14. a system as claimed in any one of the preceding claims wherein the apparatus is connected to opposite ends of each electrically conductive path. 10

15. A system as claimed in any one of the preceding claims wherein the apparatus is located in a control station and is permanently connected to one end of each electrically conductive path.

16. A system as claimed in claim 2 wherein each 15 electrically conductive path is defined by a wire connecting the apparatus to one end of a resistance comprising the first or second conduit part, an electrical connection between the other end of the resistance and one end of the interconnecting conduit, 20 and an electrical connection between the other end of the interconnecting conduit and the apparatus.

17. A system as claimed in claim 16 wherein each electrically conductive path is further defined by an electrical connection between the one end of the 25 interconnecting conduit and the other end of the interconnecting conduit.

18. A system as claimed in claim 17 wherein each 30 electrically conductive path is further defined by an electrical connection between the other end of the interconnecting conduit and the other conduit part and an electrical connection is provided between the other conduit part and the apparatus. 35

19. A system according to claim 18 or claim 2 wherein the other conduit part is provided,/on a mobi^ tanker. j'I 0 201 A system according to any one of c3 24334 - 13- 19 wherein the first conduit part comprises a stationary pipeline.

21. A system according to any one of claims 1 to 14 or 16 to 20 wherein the apparatus is provided on a mobile 5 tanker.

22. A system as claimed in claim 2 wherein the interconnecting conduit is arranged to be connected to the first and second conduit parts and is arranged to form an electrical connection between its part of the 10 electrically conductive path and the parts of the electrically conductive path associated with the first and second conduit parts.

23. A system as claimed in any one of the preceding claims wherein each conduit comprises a return 15 electrically conductive path.

24. A system as claimed in claim 23 wherein each component of the conduit when connected together provided a return electrically conductive path.

25. A system as claimed in any one of the previous 20 claims wherein the apparatus is arranged to control actuation of valves associated with each conduit when a container associated with one conduit is detected as having an expected predetermined impedance.

26. A system as claimed in claim 25 wherein the 25 interconnecting conduit is arranged to be connectable between conduit parts of different conduits.

27. a system as claimed in claim 26 wherein the display provides an indication of the resistance of the electrically conductive path of the conduit formed by 30 connecting the interconnecting conduit between two conduit parts.

28. A system as claimed in claim 27 wherein one conduit part constitutes an outlet from a reservoir and the other conduit part constitutes an inlet to a 35 receptacle.

29. A system as claimed in claim 28 wherein the 4 } 243346 - 14- mobile tanker in response to the detected impedance of one conductive path associated with one particular conduit.

30. A system in accordance with any one of the preceding claims, wherein the predetermined impedance of each conduit has a difference value.

31. A System substantially as hereinbefore described with reference to the accompanying drawings. LIQUIP SALES PTY LIMITED By Their Attorneys