In 1895, the first plant to produce seamless tubes was built. As early as 1840, ironworkers could already produce seamless tubes. Seamless tubes are typically more light weight, and have thinner walls.
Often the type of steel will also have an impact on pipe’s the strength and flexibility. The primary raw material in pipe production is steel. 5 Blooms are typically processed further before they are made into pipes.
The most common type of joint for pipes with smaller diameters is threading—tight grooves that are cut into the end of the pipe. Pipes are also inspected for defects at the end of the process. This machine fills the pipe with water and then increases the pressure to see if it holds.
“Steel Pipe.” How Products Are Made. TABLE 1. Nominal bore size steel tubes to BS 1387. Steel pipes are normally used with threaded connections. According to the principle of self-reliance and auxiliary foreign pointer, Chinese pipe steel production aims at realizing nationalization of it. According to international standards for use of steel plate in the manufacturing the submarine pipelines, China still does not have the necessary specialized steel plate (e.g., API5LX65, X70, and X80 and the X100 and X120), so it mainly relies on imports. Austenitic stainless steels, identified with the 300 series, contain a maximum of 0.15% carbon and a minimum of 16% chromium, along with nickel and/or manganese. Austenitic stainless steels are nonmagnetic and have the best high-temperature strengths of all the stainless steels.
The pipes can further be melted down and turned into other usable material in industry. The disadvantages of steel pipes include thermal conductivity, which is very poor as there is a difference in heat transfer. Steel pipe is normally used for pipelines operating at a pressure of 100 psig or more.
Steel pipe withstands high pressures, is durable, and has a long operating life cycle. Fiberglass, PVC, or high-density polyethylene (HDPE) pipe is used in certain instances for low-pressure gas gathering pipelines. Seamless pipe is seldom used in pipeline applications because of the higher cost and limited availability.
Steel pipe should be welded, except for joints which need to be taken apart for service, which will be flanged. Mild steel pipes and casing (externally flush) were commonly used since 1940s. In mines, using DC current for haulage, the steel pipes are corroded by ground current.
During 1970s, the author first replaced steel pipes by high-density polyethylene (HDPE) pipes that had many advantages as listed below: A crew of four can easily lay more than 1000 ft in a shift of 8 h compared with about 300 ft for heavy steel pipes. Pipes larger than 8 inches (200 mm) in diameter are usually not needed.
The in situ coal seam pressure may be as high as 200 psi, but the gas pipeline is seldom pressurized beyond 50 psi. Steel pipes used are API 5LX X52 and X60, with 16 inch outer dia. Table 6. Chemical Compositions of Pipes and Filler Wire Used for Welded Joint Tests.