According to the production process, high pressure alloy elbow can be divided into: high pressure alloy elbow, pressing high pressure alloy elbow, casting high pressure alloy elbow, etc.. According to the connection with the pipe can be divided into: direct welding (the most common way) flange connection, threaded connection and socket connection, etc..
High-pressure alloy elbow connecting pipe is practical, new, with reasonable structure, can make the piping stress is uniform, can simplify the pipeline system, easy to operate and can save investment and can reduce the resistance of pipeline, pipeline layout optimization, is conducive to the operation cost reduction and balanced flow distribution, reduce the vibration of the pipe lines, to ensure the safe operation of the equipment and pipeline has the advantages.
Even so, high-pressure alloy elbow note also nots allow to ignore: high pressure elbow welding when, by repeated heating precipitated carbide, lower corrosion resistance and mechanical properties; high alloy welding elbow sclerosing big, easy to produce cracks. If the same type of high pressure alloy elbow welding, must be carried out more than 300 degrees Celsius, 700 degrees Celsius after the preheating and slow cooling treatment. Or should use high-pressure alloy elbow electrode; electrode for use should be kept dry, titanium calcium type should be 150 DEG C and dried for 1 hour, low hydrogen type should be between 200 and 250 DEG C dry 1 hour (do not repeat a drying, otherwise coating are apt to crack and spalling) to prevent electrode viscous oil and other dirt, lest cause the weld increase with carbon content, and the influence of welding quality; to prevent eye corrosion due to heating, welding current should not be too large, about 20% of the carbon steel electrode is less than, arc shoulds not be too long, interlayer fast cooling, a narrow weld bead is appropriate.
Source: Yaang Pipe Industry(www.yaang.com)