tailieunhanh - Welding Pipeline Handbook

Every day countless kilometres of steel pipelines are installed worldwide for the most varied civil and industrial uses. They form real networks comparable to a system of road networks, which, although not so obvious, are definitely much more intricate and carry fluids that have become essential for us. To comply with technical specifications and fulfil the necessary safety requisites, special materials and welding processes which have evolved with the sector have been developed in recent years. The main welding process used to install the pipelines is manual welding with coated electrode, which, thanks to its ease and versatility, is still the one most used | List of contents INTRODUCTION. Joint details . Joint types. Electrode positioning angles. Pipe classification . Consumption of electrodes . ASME EN positions . THE MANUAL METAL ARC PROCESS. General information. Filler materials . Pipeweld cellulosic electrodes . Basic electrodes . Basic electrodes - Technical data. Cellulosic electrodes - Technical dfata. WELDING TECHNIQUES AND OPERATIVE PRACTICES . General information. 3 4 5 6 7 11 13 15 16 17 17 19 20 22 25 26 Pipe welding in vertical down downhill with cellulosic electrodes 1 - Preparation and tacking. 27 2 - Joint in 5G PG position. 29 3 - Joint in 6G H-L045 position . 35 Welding of pipes in vertical up uphill with mixed cellolosic basic technique 1 - Preparation and tacking. 38 2 - Joint in 5G PF position . 40 3 - Joint in 2G PC position . 44 4 - Jioint in 6G H-L045 position . 47 DEFECTS CAUSES AND REMEDIES. 49 AUTOMATIC PIPE WELDING. 53 General information. 54 Filler materials . 55 Welding techniques and operational practices . 57 Examples of WPS . 58 Comparison between three welding methods. 62 Defects and remedies . 63 1 Presentation Every day countless kilometres of steel pipelines are installed worldwide for the most varied civil and industrial uses. They form real networks comparable to a system of road networks which although not so obvious are definitely much more intricate and carry fluids that have become essential for us. To comply with technical specifications and fulfil the necessary safety requisites special materials and welding processes which have evolved with the sector have been developed in recent years. The main welding process used to install the pipelines is manual welding with coated electrode which thanks to its ease and versatility is still the one most used. However to limit costs and increase welding productivity particularly on long routes various constructors have adopted the semi-automatic or completely automatic welding process with solid wire or wire flux coated with gaseous .