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PRCI PR-185-9908
- Welding onto In-Service Thin-Wall Pipelines
- Report / Survey by Pipeline Research Council International, 08/03/2000
- Publisher: PRCI
$375.00$749.00
L51824e
Edison Welding Institute
Need: To control the risk of burnthrough, most companies prohibit welding on in-service pipelines with wall thicknesses below specified limits. The risk of burnthrough depends not only on the wall thickness however, but also on the welding parameters and the operating parameters of the pipeline. The objective of this program was to develop guidelines for safely welding onto in-service pipelines with wall thicknesses down to 0.125 in.
Benefit: The use of small diameter electrodes has a pronounced effect on the maximum allowable heat input. The use of smaller diameter electrodes allows the use of higher heat input levels.
Result: Heat input limits were determined as a function level (electrode diameter) for 0.125 and 0.156 in wall thickness pipe for methane gas at a variety of flow rates. These results tend to fall between the results generated in the laboratory for nitrogen gas and water. The most significant result seems to be the beneficial effect of current level restrictions on the risk of burnthrough.
Edison Welding Institute
Need: To control the risk of burnthrough, most companies prohibit welding on in-service pipelines with wall thicknesses below specified limits. The risk of burnthrough depends not only on the wall thickness however, but also on the welding parameters and the operating parameters of the pipeline. The objective of this program was to develop guidelines for safely welding onto in-service pipelines with wall thicknesses down to 0.125 in.
Benefit: The use of small diameter electrodes has a pronounced effect on the maximum allowable heat input. The use of smaller diameter electrodes allows the use of higher heat input levels.
Result: Heat input limits were determined as a function level (electrode diameter) for 0.125 and 0.156 in wall thickness pipe for methane gas at a variety of flow rates. These results tend to fall between the results generated in the laboratory for nitrogen gas and water. The most significant result seems to be the beneficial effect of current level restrictions on the risk of burnthrough.