C1 Spider System: Advantages

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1 C1 Spider System: Advantages Listed below are advantages that allow the C1 Spider System to stand out in the area of corrosion scanning inspection. Many of these properties came about from determining what would be the best approach to the problem after careful consideration of the task and the environment. After years of implementation in the field most of these have been confirmed as being required for a usable and efficient system. Many have been added, developed, or evolved upon approaching new issues that become apparent after continued utilization and increasing application in the field environment. 1. Maintaining magnetic field strength over changing surface geometry. This is best implemented by placing the magnets in the wheel assemblies. With other approaches, such as close proximity of the magnets in the scanner body, the surface distance of the magnet changes greatly on surfaces that are not perfectly flat over the entire inspection area. This seldom is the case. The magnetic field strength decreases exponentially with increasing distance, which makes the unit very sensitive to these changes and susceptible to falling from the tank. It is also important to use the strongest magnetic materials to increase the strength to weight ratio as much as possible. The C1 Spider uses the strongest rare earth magnets. 2. Maximizing contact with the surface via suspension. This is required for traction and adherence to the tank or vessel. We have found that having a suspension to maintain contact of the magnetic wheel assemblies is an absolute requirement. The Spider scanner has been utilized in some extreme applications, which is possible due to the greatest suspension compliance (travel) available in a remote scanner. In keeping with other requirements, this large suspension travel is accomplished using the simplest configuration possible that still meets all contact requirements. This also allowed us to do this with a very short wheel base. The Spider can maintain four wheel contact with on wheel elevated as much as 50 to 75mm. This has even allowed the unit to be turned 360 degrees inside a 20 inch pipe in one application. Tracked vehicles only maintain a high surface contact on flat surfaces. 3. High Maneuverability. During actual utilization of a remote scanner in varying conditions, it becomes very apparent that high maneuverability is an absolute requirement. This is required to recover from tight areas of obstruction, to traverse obstacles, to maintain course, etc. Surface conditions will often change the course of a scanner and without the ability to steer the scanner can become trapped in a remote area with no access. Even scanners with poor steering response are susceptible to

2 problems. The Spider can be turned 360 degrees with a very small turning radius on most surfaces. 4. High torque to weight ratio. Since the highest possible magnetic adhesion force is also a requirement, tight steering requires the highest torque possible with the minimum weight possible. The Spider has a very high torque to weight ratio and uses the best rare earth magnet servo motors available. To achieve the most optimum balance of torque to weight and maneuverability, the motor current and voltage characteristics have been optimized, also reducing cable weight. 5. High strength drive train. This high torque requires a very strong drive train while maintaining minimum weight. The gear heads are the strongest planetary type in their size range. ScanTech replaces each factory output shaft with one of our own design, which increases strength for the smaller package even further. No set screws are used to transfer torque. A high torque coupling is used from the gear head shaft to a high torque belt pulley. The wheel drive pulleys are screwed directly into the wheel assemblies. 6. Light weight, high strength, corrosion resistant materials. Each body and frame component is constructed from the most suitable material for its particular use. Engineering plastics are used for light weight where primarily compression strength is needed. The best aluminum alloys are used for higher strength components and thread durability. High strength, lightweight composites are used for areas requiring flexural rigidity. Stainless steel is used in all fasteners for corrosion resistance and on thin, non-flat components requiring high rigidity. 7. Water resistance and sealed components. Even when not using water as a couplant, these scanners often encounter wet areas where water can harm electrical components and induce corrosion. The motors on the Spider are 0-ring sealed in protective covers. Internal wiring areas are sealed. Connectors are water resistant types. The positional encoder assembly offers a level of sealing and mechanical durability that we were only able obtain by our own design, and has proven itself to be greatly superior to offthe-shelf housing assemblies. 8. Durable cabling and connectors. Cabling and connections are historically the most susceptible to damage in remote, portable systems. Connectors on the system are corrosion resistant, high

3 quality and durability sealed types of metal construction and minimum available size. Motor cables are easily replaceable, sealed and over-molded assemblies. The main umbilical cable assembly is covered with a protective sheathing offering protection and snag resistance due to cable loops. A strain relief reduces strain on the scanner end connections. Even the water coupling tubing has a high quality, small stainless steel quick-connect for connection to the scanner. All connections from the cable assembly to the scanner are made on a single, rearmounted bulkhead. 9. Higher ground clearance. A lower center of gravity is preferred. This has to be balanced with the ability to overcome obstructions and eliminate the possibility of high-centering. The Spider has a very high ground clearance and offsets the disadvantages by reducing weight on components further from the surface. 10. Remote joystick for line-of-sight control. 11. Durability. Although this is a relatively simple difference, many systems have directional controls that do not allow the ease of use the Spider joystick control offers. This control is intuitive to use, and the system includes a long connecting cable that allows the operator to move freely away from the controller and instruments to maintain line-of-sight with the scanner in distant or visually obstructed areas. The simplest design possible to accomplish design objectives is utilized. This, along with the high strength materials is used increase durability. A continual effort is made to eliminate the current weakest link in the system. 12. Ultrasonic signal strength and consistency. This property is the ultimate goal of the entire system, and is often not addressed with due diligence and importance in system trade-offs. While a dry contact, low loss wheel probe is optional on the Spider system, the bubbler technique standard with the system offers the highest signal return and consistency for remote scanning. More often than not, surfaces can compromise the effectiveness of ultrasonic coupling and the water saturation offered by the water-delay column offers signal return in areas that would require surface preparation for contact techniques. In remote areas preparation is not feasible, which is the advantage of the remote scanner in the first place. Composite element transducers are used to further maximize signal return. On heavily corroded or thin materials the system offers the flexibility to use higher frequencies and focused transducers for signals that allow the required gating. On

4 highly attenuative materials, special low frequency composite transducers are available and a special system is offered for velocity determination in cast iron. This flexibility of transducer selection is a definitive requirement for the various situations encountered in real-world field service. Another seldom-addressed aspect of signal quality is the requirement of maintaining the probe normal to the surface. The Spider transducer shoe is double-gimbaled for maximum surface conformity. The spring mounting is maximized for a more consistent tension over a large travel distance. 13. Efficient couplant delivery system. Although some systems leverage couplant-free ultrasonics for marketing purposes, in reality more effective coupling is needed for most field conditions. While offering a quality dry probe, we also have addressed the inclusion of a compact, efficient couplant supply as a standard part of the system package. This includes a small high pressure, low volume pump, a liquid filled pressure gauge, a pressure/flow adjustment valve, on/off switch and detachable power cord all housed in a small enclosure suitable for storage and portability. A water reservoir is included, but any container can be used with the pump if travel portability to a job site is of concern. Water connections are made with convenient quickconnects. 14. Comprehensive ultrasonic data acquisition package. For efficient, accurate acquisition of ultrasonic data, automated data acquisition is vastly superior to hand transcribed, single point readings. For data location correlation information, a positional encoder interface is required. The Analyst package allows all this and much more, as well as allowing the continuous scan method that is becoming more requested by customers, guidelines, and regulations. Continuous scan acquisition allows a true determination of wall conditions several times more revealing than single point readings. It also allows statistical evaluation that demonstrates data quality. Various system configurations are available for ultrasonic acquisition packages, all with various trade-offs. After utilizing and evaluating various combinations, a package was chosen with the best combination of cost effectiveness, ease of use, flexibility, performance, upgrade convenience, etc. The Spider package uses a high quality off-the-shelf flaw detector in conjunction with an off-the-shelf notebook computer and Analyst software/interface package. This combination leverages the flexibility and cost effectiveness of high-volume production compared to available application specific instruments.

5 Data storage inside portable ultrasonic instruments is not as well suited for very large amounts of formatted data. Memory requirements and user interface is not as upwardly mobile and flexible as the PC architecture. Manual transfer and formatting of data from a UT instrument is cumbersome and time-consuming. On the other end of the spectrum, completely integrated PC based systems are usually more expensive, require more training to operate, and are less flexible. The PC excels in user interface, flexibility, and data handling and presentation but is not as efficient in real-time I/O requirements as the dedicated UT instrument. Given all of the trade-offs with present technology, the UT instrument / notebook PC combination has proven to be a preferable package for this inspection. The use of a flaw detector type instrument is also much preferable compared to thickness gages. Adjustable square wave pulsers are available on the flaw detector, as well as better receiver electronics, faster screen updates, higher resolution screens, and more options. The Sonatest flaw detectors used with the system also provide the fastest digital data transfer available in portable digital flaw detectors, which is a major consideration in a scanning system. Many customers also find advantage in the fact that the ultrasonic instrument can be cross-utilized for conventional instrument-only inspections. This applies to the PC as well, where other reporting capabilities for various inspections, recording operations, and correspondence is convenient. One more very important advantage to this system is the ability to monitor the A- scan signal simultaneously with the B-scan thickness profile. The combination of PC and UT instrument allows intrinsic parallel processing completely independent of each other. This also allows constant access to the Ultrasonic control parameters independent of the PC display. Even with the power of today s PC processors, the simultaneous access of these three items has been unachievable with reasonable speed and response times. 15. Integrated reporting capability. One apparent disadvantage of the Spider electronic package is the inclusion of two electronic enclosures (UT instrument and PC) as compared to the minimum of one. Although it is easy to highlight this one detail, in the real world many compromises must be made and we did not choose trade off the many advantages for this one item. In addition to the availability of dual displays, control access, low cost of higher volume items, familiar interfaces, and easy upgrade path the architecture of this system eliminates the cumbersome transfer and formatting of data for reporting purposes. The Analyst software package has integrated automated reporting functionality. The software is built upon a database that minimizes entry of reoccurring data. It serves as a portable depository of inspection information that is useful for comparison during subsequent inspections.

6 The Analyst software allows input of inspection identification data and a convenient input of scan layout and parameters. After acquisition of the data a separate mode is available that provides automatic application of functions such as removal of irrelevant data, graphical marking of weld lines, high-average-low readings over a given data interval, minimum allowable thickness display, and graphical markup of areas with a customizable code legend for markup interpretation, as well as other functionality. These automated functions are activated by simply pressing a button on the analysis toolbar and entering the input. The software is optimized for ease of use and usability. Since the system is openloop controlled, you simply back up and re-scan any areas of data loss or when UT parameters may need to be changed. Calibration of the encoder for distance measurement using various scanners is made much simpler and easier than competitive products. Functionality exists for saving and loading UT parameters over a serial cable for consistent set-up. The list of functionality is exhaustive and help information is available under the help menu. Many systems claim to have automated reporting functions. This mostly consists of a method to export into a separate software package such as Microsoft Word or Excel. The Analyst software also has functionality for export to Excel spreadsheets, but this is normally used for special integration with other system results. In reality, getting the data into these packages is only the beginning of a long process of report preparation. As you can see, the Analyst software has already integrated the reporting information and formatted the data. After performing any analysis functions from the Analyst toolbar, you simply click on the Report Scan Plan menu item and the report is generated as a preview for your review. One more click, and it is automatically printed using your standard Windows compatible printer. At this point, you have saved hours of work normally required following the actual inspection. 16. Comprehensive system package. Due to the fact that most inspections are performed in customer facilities that may be distant from the inspection company s point of origin, logistics require that the inspection system be kept in service and free from down time. The technician may also be pre-scheduled for other travel locations. In some cases, the facilities being inspected are down for service and the time window for the inspection is very tight. When you add to this the complexity of a remote inspection system and the often brutal environment, it is very important to ensure that an incident such as a common cable failure does not cause an expensive shut-down of the inspection. While a competitor may concentrate on apparent cost comparisons, we have concentrated on minimizing effective costs and maximizing value per unit cost.. A direct comparison of cost should include the amount of system effectiveness

7 and engineering per unit cost, as well as the total offering of a standard package. While we do offer options and add-ons, the standard Spider package includes many items that are either not available or cost extra with other systems. Any additional required items should be considered from the start, rather than the base price only. The Spider package includes many items we feel may minimize the operator from the possible down time referred to above. Some of these items are listed below. A comprehensive, quality tool kit. A spare-parts kit containing common items that may be expendable or become worn such as short cables, bearings, springs, connectors, drive belts, or items that are easily lost such as fasteners and spacers. A second, spare cable for all connections including the main cable assembly. A second transducer, offered in a different frequency for alternative materials. The couplant delivery system. A hand truck for equipment mobility. The most durable storage and shipping cases available. 17. Service and Availability. As stated above, down time can be detrimental to an ongoing inspection. For occasions where the unit may have to be factory repaired or additional parts are needed, it is very important to have fast availability of parts and service. ScanTech Instruments, Inc. is known for fast, convenient service. Complete units and spare parts are stocked at a level much higher than competing systems and suppliers, some of whom maintain no stock at all. In an age of just-in-time manufacturing practices and stock reduction, ScanTech helps to buffer the customer from the harmful effects of this trend to the service industry.