Patent ID: 12203873

DETAILED DESCRIPTION

Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Throughout the following detailed description, the same reference numerals refer to the same elements in all figures.

In the current art, more and more plastic pipe is being deployed for distribution of many different fluids (gases or liquids) such as water and fuel gases (e.g., natural gas or liquid natural gas). As such plastic pipe is delivered in sections or in rolls, the current art utilizes several methods of joining two sections (or three sections in a tee) of the plastic pipe, such as butt fusion or socket fusion. These methods of fusion share one common issue—once the ends of two pipes are fused, it is almost impossible (using current art methods) to determine if the fuse is good and will withstand flexing and expected pressures.

Referring toFIG.1, a schematic view of a method of fusing of the prior and current art is shown. Note that this is but one example of how two sections of plastic pipe6are fused and not meant to be all-inclusive.

In this example, the ends of two sections of plastic pipe6are prepared (e.g., cleaned and in some cases, rotary shaved), then each section of plastic pipe is lifted off the ground (e.g., by sawhorses3) and inserted into a fusion socket8. Next, an electric potential (e.g., from a battery1through a switch2) is applied to electrical terminals9of the fusion socket8. Not visible is a coil of resistive wire7(e.g., seeFIG.4) that is wound internally to the fusion socket8running from one of the electrical terminals9to the other of the electrical terminals9. When the electric potential is applied to the electrical terminals9, the resistive wire7heats, melting some of the plastic of an outside surface of the plastic pipe6and an inside surface of the fusion socket8. After the electric potential abates (e.g., the switch2is turned off), the now co-mingled plastic cools, forming a strong bond between each end of the plastic pipe6and the fusion socket8.

There are many things that can go wrong when fusing two of the plastic pipes6, caused by, for example, moving either of the plastic pipes6before proper cooling, over shaving or uneven shaving of each end of the plastic pipes6, not cutting each of the plastic pipes6at almost exactly 90 degrees, etc.FIGS.3-21show examples of plastic pipes6that are fused as displayed by the system for non-destructive testing.

Referring toFIG.2, a failure report after destructive testing of fused plastic pipes of the prior art is shown. In the prior art, inspectors periodically, and randomly, select samples of fuses between plastic pipe6to make sure a particular fuser (a person who fuses the plastic pipe6—similar to a welder of iron or steel pipe) is making good fuses. In the example failure report100ofFIG.2, the fuser's name102and type/location of the plastic pipe6and fuse are recorded. A picture of the plastic pipes6and fusion socket8with electrical terminals9is shown before the samples are cut. Each sample is cut out of the plastic pipes6, then cut into strips and examined to determine if that sample had been fused properly. In this example, heavy scrapes106were found, measuring 0.031″ with a caliper104when the maximum allowable tolerance is 0.007″. This type of fusion often results in less melting of the plastic pipe6, thereby leading to a weak bond between the plastic pipe6and the fusion socket8that, after burying under dirt, highways, etc., often begins to leak.

The information provided by such destructive testing is somewhat of a measurement of the care and quality of the fuser, so if this fuse is suspect, it is likely that other fuses by the same fuser are also suspect and need to be inspected and likely redone.

Unfortunately, since the plastic pipe6was cut to take the above sample, it now has to be fused again, often by the same fuser.

Referring toFIG.3, a view of an x-ray imaging system of the system for non-destructive testing is shown. In this example, the plastic pipes6are shown held by saw horses3and the fuse (in this example, with a fusion socket8having electrical terminals9are shown.

A source of radiation150is held in position, for example, by legs156of a tripod. The source of radiation150is remotely controlled to emit radiation (e.g., x-rays) (optionally through a lens152) and directed at the fuse. In some embodiments, the lens152is made of a material such as Beryllium which allows enough radiation out of the source of radiation so as to penetrate the fuse, but a lower amount of radiation so as to not radiate harmful radiation towards operators of the source of radiation.

Preferably, on the opposing side of the fuse is a scanning device or a scanning plate154such as a phosphorous plate. The scanning plate154records exposure to radiation across the surface of the scanning plate154. The scanning plate154is held to the plastic pipe6at the fuse by any desired mechanism (e.g., using tape, resilient straps, rigs . . . ). As will be shown withFIG.22, after the source of radiation150is activated (initiating emission of x-ray radiation) for a period of time and the scanning plate154is exposed to the radiation through the ends of the plastic pipe6and the fusion socket8. The source of radiation150is deactivated (stopping) emission of x-ray radiation) and the scanning plate154is scanned into an image by placing the scanning plate154is placed on a scanner160(seeFIG.22), which also erases the scanning plate154so that it is ready for the next scan.

Now several examples of images captured by the system for non-destructive testing will be shown and described.

Referring toFIGS.4and5, x-ray images taken by imaging system of the system for non-destructive testing are shown. The resistive wire7of the fusion socket8is shown wrapped in a spiral within the fusion socket8. There are two issues highlighted inFIG.4. The first is a gap112between the ends of the plastic pipe6and the fusion socket8. There is a predetermined tolerance (e.g., predetermined distance) allowed for a gap112between the ends of the plastic pipe6and the fusion socket8, typically set by local or nation-wide codes for fusion of plastic pipes6. The second is an uneven or irregular spiral of the resistive wire7, as the resistive wire7(before heating) is evenly wound with each turn of the resistive wire7separated from each successive turn of the resistive wire7. These are examples of a bad fuse that is likely to fail once the plastic pipe6is pressurized or at some time before the expected end-of-life of the pipeline. In the highlighted area, there is an uneven spiral110as the windings of the resistive wire7are uneven and successive turns touch each other. This is evident of movement of the plastic pipe6before the plastic has had sufficient time for cooling. InFIG.5, a good fuse is shown as evident by a lack of gaps (gaps112inFIG.4) and a relatively even spiral of the resistive wire7.

Referring toFIGS.6,7, and8, x-ray images taken of a butt fuse by imaging system of the system for non-destructive testing are shown. InFIG.6, the x-ray image shows an uneven fuse118(an example of a bad fuse), likely caused by dirt on the ends of the plastic pipes6before fusing. InFIG.7, a void116has been detected in the x-ray image (another example of a bad fuse). Such a void will leak once the plastic pipe6is put under pressure. InFIG.8, a good butt fuse is shown in which the ends of the plastic pipe were properly cleaned, properly heated, and held together without movement until the fuse solidified.

Referring toFIGS.9and10, x-ray images taken by imaging system of the system for non-destructive testing are shown. The resistive wire7of the fusion socket8is shown wrapped in a spiral within the fusion socket8. There are two issues highlighted inFIGS.9and10. The first is voids111between the ends of the plastic pipe6and the fusion socket8. According to current standards, small voids are allowable, for example, up to 10% of the fusion zone length, or even smaller voids111in which the combined void size is less than 20% of the fusion zone length.

The second is an uneven spiral110of the resistive wire7, as the resistive wire7(before heating) is evenly wound with each turn of the resistive wire7separated from each successive turn of the resistive wire7. In the highlighted area, there is an uneven spiral110, the windings of the resistive wire7are uneven and successive turns touch each other. This is evident of movement of the plastic pipe6before the plastic has had sufficient time for cooling. These are examples of a bad fuse.

Referring toFIGS.11,12, and13, more examples of x-ray images taken by imaging system of the system for non-destructive testing are shown. The resistive wire7of the fusion socket8is shown wrapped in a spiral within the fusion socket8. Again, there is an uneven spiral110of the resistive wire7, with the resistive wire7likely shorting to itself during heating creating hot spots and cold spots. This uneven spiral110, the windings of the resistive wire7is evident of movement of the plastic pipe6before the plastic has had sufficient time for cooling. InFIG.13, another issue with the fuse is evident. There is a gap120of 0.624 inches between the ends of the two plastic pipes6. This creates a reliance totally on the strength of the fusion socket8in the area of the gap120, possibly leading to a rupture once the plastic pipes6are pressurized. This is an example of a bad fuse. Note that many local or nation-wide codes specify a maximum gap120or distance allowed between the ends of the plastic pipes6.

Referring toFIGS.14and15, x-ray images taken of a tee fusion socket joining three plastic pipes6by imaging system of the system for non-destructive testing are shown. In the case of a fusion tee8A, it is important not to insert the ends of the plastic pipe6too far into the fusion tee8A, as if the ends of the plastic pipe6are inserted too far into the fusion tee8A, the ends of the plastic pipe6will block flow of the fluid to the third leg of the fusion tee8A. The resistive wire7of the fusion tee8A is shown wrapped in a spiral within the fusion tee8A. There is only slight skewing of the resistive wire7but there is other evidence that the plastic pipe6was moved before the melted plastic of the plastic pipe6and the fusion tee8A sufficiently hardened. In FIG.15, the ends122of the plastic pipes6intrude upon the third leg of the fusion tee8A. This reduces the amount of fluid that will flow to the third leg of the fusion tee8A. Such intrusion is even more evident inFIG.17where a first one of the plastic pipes6completely blocks a second one of the plastic pipes6.

Referring toFIG.16, another x-ray image taken by imaging system of the system for non-destructive testing is shown. The resistive wire7of the fusion socket8is shown wrapped in a spiral within the fusion socket8. Again, there is an uneven spiral110of the resistive wire7, in this case one can see the top portion of the resistive wire7skewed towards the right as it was likely that the plastic pipe6to the right ofFIG.16bent downward before substantial cooling occurred. This is further evident by the gaps112between the ends of the two plastic pipes6and the fusion socket8.

Referring toFIG.17, another x-ray images of a fusion tee8A taken by imaging system of the system for non-destructive testing is shown. To repeat, in the case of a fusion tee8A, it is important not to insert the ends of the plastic pipe6too far into the fusion tee8A. If the ends of the plastic pipe6are inserted too far into the fusion tee8A, the ends of the plastic pipe6will block flow of the fluid to the third leg of the fusion tee8A. In the example ofFIG.17, the end126of one of the plastic pipes6intrudes upon the third leg of the fusion tee8A, totally occluding fluid flow to/from the third leg of the fusion tee8A.

Referring toFIGS.19through21, x-ray images of an electrofusion service tee taken by imaging system of the system for non-destructive testing are shown. InFIG.18, a failure report of the prior art is shown in which one tap tee8D remains connected to the plastic pipe6but another tap tee8d(not shown) fell off of the plastic pipe6at the location of the tap hole128. InFIG.19, reasons for such failure are evident as the same fuser likely made both fuses. There is a blow out130near the electrical contact9D and several of the resistive wires7D have shorted131, as the tap tee8D was likely moved before the plastic of the tap tee8D and the plastic pipe6cooled enough to harden. The same is shown from the side inFIG.20and the uneven spiral110appears to have a short between turns of the resistive wire7D is shown from the side inFIG.21.

Many of the above issues with butt fuses, fusion socket8, fusion tees8A, tap tees8D, etc., are not evident until either a destructive test is performed or a field failure occurs. Being that the plastic pipes6are often buried underground, often under roadways, sidewalks, parking lots, etc., a failed fuse is often very difficult to find and expensive to repair.

Referring toFIG.22, a schematic view of the system for non-destructive testing is shown. The source of radiation150(e.g., x-ray radiation) is shown in position, in this example, above a fusion socket8that connects two sections of the plastic pipe6. The source of radiation150is remotely controlled to emit radiation (e.g., x-rays) through a lens152and directed at the fuse, in this case, the fusion socket8, though any thermal fuse of two or more plastic parts (e.g., plastic pipes6). In some embodiments, the lens152is made of a material such as Beryllium which allows enough radiation out of the source of radiation so as to penetrate the fuse, but a lower amount of radiation so as to not radiate harmful radiation towards operators of the source of radiation.

On the other side of the fuse (or in this example, fusion socket8) is a scanning plate154such as a phosphorous plate. The scanning plate154records exposure to radiation across the surface of the scanning plate154. After the source of radiation150is activated for a period of time and the scanning plate154is exposed to the radiation through the ends of the plastic pipe6and the fusion socket8, the scanning plate154is removed and places upon a scanner160. The scanner scans an image from the scanning plate154while also erasing the scanning plate154so that it is ready for the next scan. The scanner160is, for example, computed radiography scanner and the amount of radiation received at each pixel of the scanning plate is recorded to create an x-ray image of the fuse. An example of a scanner160is a computed radiography scanner such as the CR 4100 produced by Virtual Media Integration of Pensacola, Florida, USA. Note that as technology progresses, it is fully anticipated that the image generation will be automatic from the scanning plate154without need of a separate scanner160.

The scanner160is operatively coupled to a computer500(seeFIG.25) where the x-ray image is stored, enhanced, recognized, and/or displayed on, for example, a display586. Note that it is fully anticipated that instead of using a plate system, a sensor array (scanner) be positioned at the fuse6and the x-ray image is scanned by the sensor array and copied directly into the computer.

In some usage scenarios, the system for non-destructive testing is installed in a vehicle (e.g., a van) so that the images are available for review immediately and any unacceptable fuses be recognized and removed (cut out and re-fused) before burying underground.

As it is important to archive results of testing and to provide feedback to the company performing the fusing and the employees performing the fusing (fusers), the images are often saved in storage such as persistent memory574(seeFIG.25) of the computer500and the images (and reports) are anticipated to be transferred to remote storage either using removable storage removably interfaced to the computer500or by transferring the images (and reports) over a network502(seeFIG.25) for remote storage, viewing, analysis, feedback, etc.

In some embodiments, software running on the computer500recognizes some or all flaws using image enhancement and recognition. For example, as the resistive wires7are typically factory wound in an evenly spaced spiral. Image recognition detects the contrast of the resistive wires7against the plastic of the fusion socket8and the plastic of the plastic pipe6and the software measures the continuous distance between each turn/loop of the resistive wire7, detecting if two adjacent turns of the resistive wire7are too close or too far from each other. In a similar way, the software locates each end of the plastic pipe6within the fusion socket8and determines if each end is close enough to each other. As for a fusion tee8A, the software locates each end of the plastic pipe6within the fusion tee8A and determines if the ends of the plastic pipe6encroach upon the third leg of the fusion tee8A.

Referring toFIGS.23-24, exemplary flow diagrams of the system for non-destructive testing are shown. The flow begins with erasing400the scanning plate154(if the scanning plate154was not previously erased). Now the source of radiation150and the scanning plate154are positioned402on opposite sides of the fuse. Note that often images of the same fuse are captured at different angles to detect problems that are not evident from only one angle.

Now the source of radiation150is enabled to emit404radiation (e.g., x-rays). Once the source of radiation150is stopped, the scanning plate154is moved406to the scanner160and scanned to extract the x-ray image of the fuse. The x-ray image of the fuse is then stored408(e.g., in persistent memory574of the computer). If there are more fuses to test410, the above is repeated, otherwise the non-destructive testing is complete.

InFIG.24, an exemplary program flow of an automated fuse quality check is shown for one x-ray image, though the same is applied to all x-ray images as desired. In this, the software reads420the x-ray image (e.g., from persistent memory574) and analyzes422the x-ray image by, for example, enhancing the x-ray image, detecting the resistive wires7, detecting outer edges and ends of the plastic pipes6, detecting inner edges of the socket8/8A/8D, etc.

In this example, the software determines if there is skewing426of the resistive wires7, and if there is skewing426of the resistive wires7, the software records the skewing426in the report for that fuse. Note that such skewing is determined by a pre-set tolerance of skewing of the resistive wires7based upon local or industry standards.

Now, the software determines if there is/are gaps428between the ends of the plastic pipes6, and if there is/are gaps428between the ends of the plastic pipes6, the software records the gaps430in the report for that fuse. Note that an acceptable gap is determined by a pre-set gap tolerance based upon local or industry standards.

Now, the software determines if there is/are coupling gaps432between the ends of the plastic pipes6and the fusion socket8/8A, and if there is/are coupling gaps432, the software records the coupling gaps434in the report for that fuse. Note that an acceptable coupling gap is determined by a pre-set gap tolerance based upon local or industry standards.

Next, a report is generated436including the location of the fuse, an identification of the fuser, etc.

Also, in some embodiments, a global fuser database is updated438with qualitative measurements of the fuse as well as issues found with the fuse. In this way, each fuser will have a history showing a percentage of faulty fuses, overall quality numbers, quality trajectories (e.g., quality improving or falling), etc., for use in determining how many of that fuser's fuses need inspection, performance reviews, etc. For example, if 50% of fuses made by a particular fuser are faulty, then all fuses by that fuser need to be inspected and that fuser needs feedback and/or disciplinary action, etc.

Referring toFIG.25, a schematic of a typical computer system as used by the system for non-destructive testing is shown. The example typical computer system500represents a typical device used as in the Referring to. This typical computer system500is shown in its simplest form. Different architectures are known that accomplish similar results in a similar fashion and the present invention is not limited in any way to any particular computer system architecture or implementation. In this exemplary computer system, a processor570executes or runs programs in a random-access memory575. The programs are generally stored within a persistent memory574and loaded into the random-access memory575when needed. The processor570is any processor, typically a processor designed for computer systems with any number of core processing elements, etc. The random-access memory575is connected to the processor by, for example, a memory bus572. The random-access memory575is any memory suitable for connection and operation with the selected processor570, such as SRAM, DRAM, SDRAM, RDRAM, DDR, DDR-2, etc. The persistent memory574is any type, configuration, capacity of memory suitable for persistently storing data, for example, magnetic storage, flash memory, read only memory, battery-backed memory, magnetic memory, etc. The persistent memory574is typically interfaced to the processor570through a system bus582, or any other interface as known in the industry. In some embodiments, the persistent memory574has stored therein a database of fusers (person who fuses the plastic pipes6) and each fuse performed by a specific fuser in the database of fusers is associated with that fuser and/or the quality of the fuse is associated with that fuser. In this way, quality feedback is available for the fusers (e.g., 1% of the fuses made by a certain fuser are bad).

Also shown connected to the system bus582is a network interface580(e.g., for connecting to other computers through a network502), a graphics adapter584and a keyboard interface592(e.g., Universal Serial Bus—USB). The graphics adapter584receives information from the processor570and controls what is depicted on a display586(e.g., displaying of x-ray images). The keyboard interface592provides navigation, data entry, and selection features. In some embodiments, the display586is a large screen graphics display for field view and analysis of fuses (e.g., to show and explain the issues to the fuser, etc.).

In general, some portion of the persistent memory574is used to store programs, executable code, data, scanned x-ray images, etc.

The peripherals are examples and other devices are known in the industry such as pointing devices, touch-screen interfaces, speakers, microphones, USB interfaces, Bluetooth transceivers, Wi-Fi transceivers, image sensors, temperature sensors, etc., the details of which are not shown for brevity and clarity reasons.

Equivalent elements can be substituted for the ones set forth above such that they perform in substantially the same manner in substantially the same way for achieving substantially the same result.

It is believed that the system and method as described and many of its attendant advantages will be understood by the foregoing description. It is also believed that it will be apparent that various changes may be made in the form, construction and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely exemplary and explanatory embodiment thereof. It is the intention of the following claims to encompass and include such changes.