Use of natural gas as an eco-friendly and user-friendly fuel increases day by day, in parallel to developments in industry and need for comfort. The common use of natural gas arouses interest about gas transfer and joining of pipes in order to install gas pipe lines. In this study, two methods to join PE plastic pipes are compared: electro-melting welding and hot element (butt) welding methods. Tests are applied in order to measure the leaktightness and strength properties of the joined pipes in ambient conditions similar to actual working conditions. Results of the standardized tests are compared. Consequently, electro-melting welding is found to be the ideal method for pipes of certain diameters. However, for main transfer line pipes (of larger diameters), hot butt welding gave more successful results.