Pipeline Welding for Today’s Energy Demands
Pipeline welding requires speed as well as precision. The speed of the welding is directly related to how much pipe a contactor can put in the ground. Each weld must pass visual and x-ray inspection, and must meet API 1104 Weld Procedure Specification.
Pipe operating conditions in the handling of oil, gases, water, and other substances range from high vacuum to pressure of several thousand pounds per square inch. Mechanical joints are not satisfactory for many of these services. Electric arc or oxyacetylene welding provide effective joints in these services and also reduce weight, increase the strength, and lower the cost of pipe installations.
PREPARATION FOR WELDING
a. Pipe Beveled by Manufacturer. If cut in field, it must be beveled.
b. Cutting of Pipe. The pipe must be cut in a true circle in a planeperpendicular to the center line of the pipe.
c. Cleaning of Pipe. Remove all rust, dirt, scale, or other foreign matter and oxide formed by oxyacetylene cutting.
d. Aligning the Joint. A pipe lineup clamp should be used to align and securely hold the pipe ends before tack welding.
The most commonly used processes for joining pipe are the manual oxyacetylene process and manual shielded metal-arc process.
The manual shielded Metal-arc process may be used for welding all metals used in piping systems and can be used for welding pipe materials such as aluminum, magnesium, and high chromium-nickel alloys that are difficult to weld by other processes.
Oxyacetylene welding is generally limited to small size piping or to welding operations where clearances around the joints are small.
PIPE WELDING PROCEDURES
Welding in the horizontal fixed position.
1. Starting at the bottom of 6 o’clock position, weld upward to the 3 o’clock position.
2.Starting back at the bottom, weld upward to the 9 o’clock position.
3. Starting back at the 3 o’clock position, weld to the top.
4. Starting back at the 9 o’clock position, weld upward to the top overlapping the bead.
When welding downward.
1. Start at the top overlapping the bead.
2. Work down one side to the bottom.
3. Work down the other side to join with the previous weld at the bottom.
New technologies and methods are being developed to automate many of the processes.
Globally, demand for natural gas continues to rise. A substantial number of pipeline projects have moved into remote regions to extract gas to meet the increasing demand. Some of these projects cross a variety of terrains and altitudes with exposure to harsh and demanding conditions. Offshore oil and gas drilling requires precision welds, even underwater.
The welds have to withstand pressure from the oil or gas inside the pipe and extreme weather conditions, even earthquakes.
PIPELINE WELDING JOBS – WHAT DO THEY HAVE TO OFFER? GET THE DETAILS
Pipeline fusing or melting jobs have been customarily partaken in since welded pipes fool around an necessary partial in a execution of most industrialized projects. This direct for welded pipes, creates employment. …
Publish Date: 06/18/2010 5:19
http://www.career.org.nz/?p=711
Internal pressure test succeeds where other measures fail – Oil …
X-ray examination took place on all the pipeline’s girth weld seams before the internal pressure test, potentially exposing disqualification flaws at the crack origination position. A combination of inadequate equipment and …
Publish Date: 02/08/2010 1:00
http://www.ogj.com/index/article-display.articles.oil-gas-journal.volume-108.issue-5.technology.internal-pressure.QP129867.dcmp=rss.page=1.html
Dedicated to just some of the welders I worked with this year on the pipeline. 2009
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Miller Engine-Driven 350 Welder PipePro – JoeWelder.com™
The Big Blue 350 PipePro, purpose-built for transmission pipeline welding, provides 20 to 400 amps for both DC Stick (325 amps at 100 percent duty cycle) and DC TIG welding, 14 to 40 volts for MIG and Flux Cored welding (350 amps at 100 …
Publish Date: 09/15/2010 12:37
http://joewelder.com/2010/09/15/miller-engine-driven-350-welder-pipepro/
Pipeline Welding Jobs – A Good Job To Depend On? Details Inside …
Welders participating in pipeline welding jobs play an important role in making sure pipes are joined together properly. This creates employment, but what about.
Publish Date: 06/14/2010 13:57
http://www.lost.ws/?p=29467
Explore a Career – Welding and Pipelaying in Pipeline Construction
Use this video with the Careers section at pipeline.ca. Pipeline construction is an exciting, on the leading edge of technology business. This short video helps with introducing careers that involve welding and pipelaying within Canada’s mainline (la…
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