Steel pipes have been used in water transmission lines in the United States since the early 1850s. Previously, steel pipes were produced by rolling steel sheets and plates into a tubular form and riveting the joints. This method, which is quite suitable for pipe production, continued until the 1930s with some improvements. The different pressure demands of a pipeline design could easily be met by changing the wall thickness.
Compared to today, project engineers previously determined the safe project pressure as 10,000,- psi (689 bar) due to the low tensile strength of the steels used at that time, the low efficiency of cold riveted joints and their interlocking connections in the form of riveted or stovepipes. Riveted connections are stronger and more durable. Over the years, as riveted pipe production methods have improved and higher-strength steels have been produced, project pressures have generally increased to 12,500,-, 13,750,-, and finally 15,000,- psi, depending on the efficiency of riveted joints, with a safety factor of ¼ of the tensile strength. has risen up. Pipe diameters ranged from 4 inches to 144 inches, with wall thicknesses ranging from 0.04 inches to 1.5 inches. There were production methods with single, double, triple or even four rivets with efficiencies varying between 45% and 90% according to the project.
Developed in 1905, the bolt-lock tube almost completely replaced the riveted tube by the 1930s. Production Cut 30 ft (9.14 m) long plates to a length approximately half the desired pipe circumference, form 30 ft long semicircular grooves by squeezing the long sides from both sides, and combine two grooves with special H-shaped sliders to form a full circle. It was made by the method of manufacturing a pipe.
According to the general procedure at that time, steel with a final tensile strength of 55,000,-psi was used. The project pressure would be 13,750 psi with a 4 to 1 safety factor. Bolt-lock pipes had significant advantages over riveted pipes. This type of pipe has only one or two straight joints and did not have any round joints. Straight joints were considered 100% efficient, compared to the 45% – 70% efficiency usually applied to riveted joints. Barrel-lock tubing, with tube diameters from 20 inches to 74 inches and wall thicknesses from 3/16 inches to ½ inches, played an important role in tube manufacture until the invention of automatic electric welding in the mid-1920s.
Until the first half of the 1930s, the old methods were replaced by welded pipes. Automatic electric fusion welding offered significant advantages such as fewer parts, fewer processes, faster production, little outward protrusion of the joints and 100% efficiency of the welds. Manufacturers of fusion welded tubing used more or less the production sequence of bolt-lock tubing in the early days. 30 ft long plates were used throughout the 1930s and 1940s. Until the 1950s, some companies had supplied sheets of 40 ft long, and a few were making sheets of this length in presses.
In the 1930s, during the development of the welding method, an important innovation was brought about the project pressure. Until then it was common practice to work with a factor of safety of one quarter of the final pulling force. As the production of welded pipes increased, the idea of using 50% of the yield force as the project pressure was generally accepted.
Spiral shaped welded pipe was developed in the early 1930s and was used extensively in pipe diameters from 4 inches to 36 inches. Welding was done by electric fusion method. After the Second World War, German machines were imported, and then machines capable of spiral forming and welding up to 144 inch pipe diameters were developed.
Source; AWWA M11 American Water Works Association, Handbook of Water Supply Applications, Design and Placement Principles of Steel Pipes.
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