Oil pipeline must use a certain connection to form a complete system. Connection methods of pipeline are mainly three categories, including screw thread, welding and flange connection.
When the pressure is not high, the pipe with small diameter can be connected by using screw thread this method. This connection method is very convenient, but most of the diameter of oil pipelines are generally larger, so other two connection methods are used commonly.
The pipeline that DN≥50 basically uses welding method to connect. Welding has many advantages, such as convenient construction, strong, tight and saving steels. The general straight pipe or bends those parts do not need to tear down can use this method.
The connection of pipes and valves or other equipment (such as: pump) and the parts those need to disassemble of pipeline need to use flange to connect. In order to ensure the tightness of the flange connection, we also need to use a relatively soft flange grommet to assist on both sides of the flange. According to the production process, flange can be divided into flat welding, thread, butt welding, loose tube and blind plate and other types. Except blind plate flange, others are all used in interconnection between the pipeline. If you need to connect different diameters of the pipeline, you can use the adapter flange that two diameter corresponding. The blind plate flange is used to close the end of the pipe head. Therefore design of it make it can withstand greater bending stresses.
