The United States consumes an incredible amount of energy every day, and this demand for energy shows no signs of decreasing. The U.S. pipeline infrastructure is critical to supporting this growing demand. We take a look at this infrastructure and break down some of the facts including age, material, miles and production.
Cars, we rely on them to get us from point A to point B on a daily basis. Through the years, car manufacturers have been driven to create a faster, safer and more economical vehicle to keep up with competition. One of the issues the automotive industry faced was how to reduce the weight of the car while increasing the strength to protect drivers involved in accidents. The solution was Tailor Welded Blanks.
Corrosion and cracking present problems for every industry that relies on pipelines to transport liquid and gas products. There are many different kinds of techniques and equipment used for examining pipelines. These vary based on specific needs, access restrictions, and environmental conditions. In the last few years, electromagnetic acoustic transducer (EMAT) has come to prominence for its ability to quickly scan exposed pipelines for corrosion, cracks, and other defects using medium-range guided waves and without the requirement for liquid couplants. Recent sensor and technique developments have now enhanced these capabilities to reliably inspect inaccessible or difficult to access areas for corrosion, such as the undersides of pipe supports and pipes with heavy coatings.
Electric resistance welding (ERW) is a process for creating spot or seam welds by using the electrical resistance of a material, combined with time and the force used to hold the materials together during welding. While ERW is a beneficial method for producing forged welds, the process is not perfect. Typical defects that can develop in the ERW process are:
In the realm of science, corrosion has been the subject of study for more than 150 years. It occurs naturally when a material (typically metal) or its properties deteriorate due to a reaction with its environment. The latest estimates by the World Corrosion Organization place the annual cost of corrosion worldwide at around $2.2 trillion USD, which is over 3% of the world GDP. While there are many types of corrosion and corrosion can form on many structures and in many areas, this discussion is focused on energy pipeline corrosion. There are currently over 2 million miles of oil and gas pipelines in the United States alone. These pipelines are important because they supply the fuel needed to power our communities and economies. They are the energy lifeline that sustains our nations, but they are vulnerable.
There are many techniques used to perform thickness measurements in manufacturing environments. Traditional thickness measurement options include Isotope, X-Ray, Laser Optical, Piezo Ultrasonic, and Laser Ultrasonic. An effective, yet underutilized technique is EMAT (Electro Magnetic Acoustic Transducer) generated UT. EMAT generates ultrasonic sound waves in the material being inspected and measures the Time-Of-Flight (TOF) of the signal through the part to calculate the thickness.
The Medium Range UT (MRUT) system was developed to decrease the amount of time it takes to inspect pipelines while also providing a full volumetric inspection and maintaining highly sensitive defect detection capabilities. This system harnesses the use of Electro Magnetic Acoustic Transducer (EMAT) technology which gives the MRUT distinct advantages over other inspection methods. Why choose the MRUT system with EMAT technology?
The conversion of electrical pulses to mechanical vibrations and the conversion of returned mechanical vibrations back into electrical energy is the basis for ultrasonic testing (UT). Although there are non-contact options available for some applications (e.g. EMAT), the most widely used technique involves using a piezoelectric element to generate the ultrasound. Due to the impedance mismatch between the piezoelectric transducer and the material inspected, a liquid couplant is typically used to transmit the vibrations from the transducer into the part and receive the vibrations back into the transducer. While this technique is very efficient and popular, liquid couplants used for ultrasonic inspection have some inherent limitations and disadvantages. The liquid couplant itself is sensitive to extreme weather conditions, can be harmful to the part and environment, can make some inspections cumbersome or impossible, and their use and disposal can be expensive. An alternative method to using liquid couplant is Dry-Coupled Ultrasonic Testing (DCUT).
Innerspec is introducing a hardware and software upgrade for their PowerBox H, the first high-power portable EMAT instrument in the market, to improve its MRUT (Medium Range UT) application. The MRUT technique uses guided waves with a typical inspection range between 0.1m (4”) and 5m (200”) to detect corrosion, cracks and discontinuities on tubes, gas lines, oil pipelines and storage tanks. This system uses Electro Magnetic Acoustic Transducer (EMAT) technology to perform fast scanning on exposed tubes and tanks as well as inspect inaccessible areas from a fixed position. With the use of higher frequencies and a shorter range, this technique detects isolated pitting and wall loss with up to 10 times better resolution than Long Range UT systems.
Readers were previously introduced to some of the practical advantages of EMAT Ultrasonic Testing (UT) in the March/April 2013 and July/August 2013 issues of Inspectioneering Journal. These advantages include dry inspection, an imperviousness to surface conditions, and unique wave modes such as shear waves with horizontal polarization (SH waves). In this article, I will cover the practical advantages of EMAT for in-service applications using Medium Range Ultrasonic Testing (MRUT).
We are pleased to announce that our MRUT (Medium Range UT) hand-held scanner and Innerspec PowerBox H instrument have successfully passed several qualification tests in North America and the Middle East, and it is now standard equipment for corrosion detection by most oil majors. The Innerspec PowerBox H is the first portable, battery-operated instrument that can run EMAT (bulk and guided waves) and conventional piezoelectric transducers. This system complements our automated MRUT system which has been in the market since 2008.