Abstract
The purpose of this study is joining main and branch gas pipes by friction welding without digging a paved road. By this development, only making a hole at vertical side of the paved road, the branch pipe can be connected to main pipe. In this study, an end face of branch pipe was welded to a side of main pipe. Furthermore, in consideration that gas main pipe is laid in the ground, an influence of mud on joining state is examined.
The experimental results are as follows;
1) Branch pipe welding without digging a paved road was enabled by friction welding method.
2) Developed method does not require digging and repairing the paved road. Therefore, construction cost can be reduced, and traffic is not obstructed.
3) Tensile strength and elongation of branch pipe friction welded joint were 17.7∼17.8MPa and 520∼525%, respectively. These were nearly equal to those of the base polyethylene.
4) A large amount of mud was eliminated from faying surface by friction. Therefore, the influence of the mud on tensile strength and elongation was not recognized.
