What pipe does De represent?
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Pipes are denoted by De. What does De mean? For example, De63
De mainly refers to the outer diameter of the pipe; it is generally denoted by De, and such values always need to be specified in the form of outer diameter X wall thickness.
What was said upstairs was very professional! The nominal diameter is denoted by the symbol DN; the diameter can be divided into outer diameter, inner diameter, and nominal diameter. For pipes that are seamless steel tubes, the outer diameter is denoted by the letter D, followed by the size of the outer diameter and the wall thickness. For example, a seamless steel tube with an outer diameter of 108 mm and a wall thickness of 5 MM is indicated as D108*5. Plastic pipes are also specified using their outer diameter; for instance, De63. Pipes made of reinforced concrete, cast iron, galvanized steel, etc., are denoted by DN. In design drawings, the nominal diameter is generally used for representation. The nominal diameter is a standard established artificially for the convenience of design, manufacturing, and maintenance; it is different from the actual inner diameter, and serves as the specification name for pipes (or pipe fittings). The nominal diameter of a pipe is not equal to its inner or outer diameter. For example, for a seamless steel pipe with a nominal diameter of 100 MM, there are several variations such as 102*5 and 108*5. Here, 108 represents the outer diameter of the pipe, while 5 indicates the wall thickness. Thus, the inner diameter of this pipe is (108*5 – 5) = 98 MM. This value is not exactly equal to the outer diameter minus twice the wall thickness. In other words, the nominal diameter is a specification name for the pipe diameter that is close to, but not exactly equal to, the inner diameter. In design drawings, the nominal diameter is used so that the structural and connection dimensions of pipes, fittings, valves, flanges, gaskets, etc., can be determined based on it. The nominal diameter is denoted by the symbol DN. If the outer diameter is used in the design drawings, a table showing the specifications of the pipe, including its nominal diameter and wall thickness, should also be provided.
The outer diameter is denoted by φ; I’ve never seen D used to represent the outer diameter
De stands for Diameter External, referring to the outer diameter; it is generally used for plastic water pipes, while it is not commonly used on chemical industry steel pipes
Why not standardize the notation for pipes?
The nominal diameter of plastic pipes is denoted by De
It generally indicates the nominal diameter of plastic pipes