The tube that used in Oil pipeline is mainly carbon steel pipe, according to its manufacturing process, it can be divided into seamless steel pipe and welded steel pipe.
Seamless steel pipe has the characteristics of high strength, specifications and more features, so it is applicable to transport strong corrosive oil or transport in the high temperature conditions. The technology of seamless steel pipe is divided into hot rolling and cold drawn. As the cold drawing process will cause the material hardening, it also needs to do the corresponding heat treatment based on the specific use of pipe.
Welded steel pipe can be divided into two kinds, straight seam steel pipes (LSAW steel pipe) and spiral welded pipe (SSAW steel pipe). The process characteristics of carbon steel pipe leds the steel pipe to tend to become brittle at low temperatures, so it is mainly applied to the normal temperature pipeline, the use of pipe temperature should not exceed 300 degrees Celsius. In general, the temperature of ordinary carbon steel pipe is between 0 to 300 degrees Celsius. If using the high-quality carbon steel pipe, the temperature range can be broadened from -40 to 450 degrees Celsius. The experimental pressure of the steel pipe is generally 1.5 times of the nominal pressure. When the temperature of the material delivered does not exceed 200 degrees Celsius, the working pressure is the nominal pressure. When the temperature exceeds 200 degrees Celsius, the working pressure should be correspondingly lower than the nominal pressure.