JFE Steel Corporation
JFE Steel Develops World’s First Large-Scale Bending Test Rig
for Large-Diameter, High-Strength Linepipe
— Demonstrated 48-inch HIPER®’s High-Strain Capacity —
Tokyo – JFE Steel Corporation has developed the world’s first large-scale bending test rig that can validate the bending capacity of high-strength linepipes up to 48 inches (1,219 mm) in outside diameter. The test rig confirms critical buckling deformation and final failure of pressurized linepipes by applying large bending moment.
JFE Steel developed HIPER®* (High Performance for earthquake resistance), a linepipe with high strength and high-strain capacity, ahead of other companies in 2000. The new test rig enables demonstration of the high-strain capacity of a 48-inch HIPER® linepipe. The company conducted a validation test with the rig, in the presence of the customer, on a 48-inch API X80-grade** HIPER® linepipe which was produced for the Second West-East Gas Pipeline This pipeline has transported natural gas from the Talim Basin of western China to the customers in eastern China, a distance of about 4,800 kilometers, since 2009.
The pipes will help meet the rising demand for natural gas, 75% of which is transported through pipelines, often high-pressure pipelines covering long distances. Since the linepipes are sometimes constructed in seismic and/or permafrost areas, they must offer strength sufficient to withstand extreme external forces and be flexible to survive abrupt ground movement.
HIPER® has the capability to deform flexibly despite its high strength. It not only improves safety, it also reduces construction costs by improving bending capacity through material design without increasing wall thickness. In recognition of these properties, 48-inch API X80-grade HIPER® was chosen for the use in seismic zones along the Second West-East Gas Pipeline.
Previously, JFE Steel conducted validation tests on the high-strain capacity of 20-inch to 36-inch HIPER® and conventional linepipes. It established calculation techniques to estimate the bending capacity of up to 36-inch linepipes with great accuracy by examining the validation of a finite element model. The recently developed test rig demonstrates the high-strain capacity of large-diameter, high-strength HIPER® by using actual linepipes, and establishes a simulation technique to estimate bending capacity. As a result, the rig will contribute to practical use of 48-inch high-strength linepipes, which will lead to the steady supply of natural gas.
JFE Steel is now aiming to develop various sizes and strengths of HIPER® products using the test rig for strain capacity validation in hopes of securing orders for both the upcoming West-East Gas Pipeline project beginning in 2012 (almost the same scale as the Second West-East Gas Pipe line) and the giant Alaska Gas Pipeline project to transport natural gas a distance of about 2,800 km, from northern Alaska through Canada to the continental U.S.A., beginning in 2018.
Test Rig Specifications
|Maximum diameter of test pipe:||48 inches (Maximum wall thickness: 30 mm)|
|Maximum length of test pipe:||8 meters|
|Maximum load of hydraulic jack:||6,000 kN|
|Maximum bending moment:||35,000 kN/m|
|Maximum internal pressure:||30MPa|
*HIPER® is a high-quality linepipe offering greater high-strain capacity than conventional linepipes. It is made from high-strength thick steel sheet produced by Super-OLAC (OnLine Accelerated Cooling), which combines high-precision temperature control and high-cooling performance at the rolling process. This realizes linepipe featuring superior weldability and toughness in addition to high-strength. It also incorporates the Heat-treatment On-line Process (HOP) to meet demands for high-level material quality.
|Orders:||2,660 tons in Japan and 63,445 tons overseas (as of March 2010)|
|Awards:||34th Iwatani Naoji Memorial Award in 2007
Commendation for Science and Technology (Development Category) from the Minister of Education, Culture, Sports, Science and Technology in 2010
**API X80 grade
This strength grade for linepipes, which is based on standards of the American Petroleum Institute (API), is equivalent to linepipes with more than 555MPa yield strength.
Overview of the 48-inch linepipe bending test
Buckling deformation status of a linepipe after the bending test
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|JFE Steel Corporation:||www.jfe-steel.co.jp/cgi-bin/contact.cgi|