In March 1927, the American Standards Association authorized a special committee to develop dimensional standards for wrought steel, wrought iron and tubing. At that time only pipe wall thicknesses were standardized and used: standard weight (STD) for extra-strong (XS), and twice extra-strong (XXS) pipes, depending on iron pipe size (IPS). However, these parameters were not sufficient for practical applications. The committee surveyed the industry and developed a graphical system of numerical wall thickness and pipe size ratios equivalent to IPS and NPS.

The original intent was that each graph would relate the parameters (wall thickness and nominal pressure, but the scatter of numbers was such that this initial objective was not met. The STD, XS, and XXS standards were supposed to be discontinued in 1939, but they were still widely used. They are sometimes referred to as the standards, extra heavy (XH) and double extra heavy (XXH) pipe, respectively.

Many changes and additions were made to the original table of standards to facilitate practical use. Thus, modern industrial standards of API, ASTM, and others were created.

In the mid-20th century, stainless steel made it possible to replace thick-walled pipes with lighter, thinner walled pipes with less risk of pipeline system failure due to corrosion. By 1949, standard tables were created for thin 5S and 10S, which took into account pressure change requirements to the nearest BWGnumber, as well as other regulations for "S" steel pipe. According to ASME, the thinnest "S" pipes cannot be threaded because of the thin wall. Such pipes must be joined by welding.

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Evek GmbH has a wide range of high quality rolled steel products in standard and non-standard sizes in stock. We deliver stainless steel pipes of various brands in retail and wholesale. All the products have quality certificate for compliance with standards and technical conditions of operation. The certificate marks the manufacturer, alloy grade, melting number, chemical composition and mechanical properties. Implementation of orders - in the shortest possible time. Preferential discounts are available for wholesale customers.