In general, the diameter of spiral steel tubes can be classified into outer diameter, inner diameter, and nominal diameter. The outer diameter of a spiral steel tube is denoted by the letter "D," followed by the dimensions of the outer diameter and wall thickness. For instance, a seamless steel tube with an outer diameter of 108mm and a wall thickness of 5mm is represented as D108*5. Similarly, plastic pipes are also indicated by their outer diameters, such as De63. Other materials like reinforced concrete pipes, cast iron pipes, and galvanized pipes use DN for representation. In design drawings, the nominal diameter is typically adopted, which is a standardized measurement for design, manufacturing, and maintenance convenience. It is also known as the nominal bore and serves as the specification name for pipes (or pipe fittings).
The nominal diameter of a pipe does not equal its inner or outer diameter. For example, a spiral steel tube with a nominal diameter of 100mm can have various dimensions like 1025 or 1085. Here, 108 represents the outer diameter, and 5 indicates the wall thickness. Therefore, the inner diameter of this steel tube is (108-2*5)=98mm, but it is not exactly equal to the difference between the outer diameter and twice the wall thickness. In other words, the nominal diameter is a specification name that approximates the inner diameter but does not equal it. The use of nominal diameter in design drawings facilitates determining the structural and connection dimensions of pipes, fittings, valves, flanges, gaskets, etc. The nominal diameter is denoted by the symbol DN. If the outer diameter is used in design drawings, a pipe specification comparison table should be provided, indicating the nominal diameter and wall thickness of each pipe type.
Achieving Energy Saving in Spiral Steel Tubes for Fluid Transportation:
To achieve energy saving in spiral steel tubes for fluid transportation, measures are taken to capitalize on seasonal temperature changes, particularly during late autumn when temperatures drop. By reasonably starting and stopping the operation of cooling tower fans and axial fans in pump houses used for cooling, electricity consumption is effectively reduced. According to professional management estimates, this alone can save nearly RMB 100,000 per month. In daily operations, 15 sets of cooling tower fans run simultaneously at full capacity, consuming a total power of up to 1600kW per hour, making them significant electricity consumers.
Given the specific requirements for water medium supply in steelmaking and continuous casting systems, especially when refining high-quality steel grades, precise control of water temperature differences is crucial for stabilizing product quality and facilitating the development of new steel grades.
Actively communicating with each production line user point to gain a deep understanding of specific water temperature requirements enables determining the most reasonable range, thereby achieving cost reduction and efficiency enhancement while meeting production needs. By leveraging seasonal changes and the decrease in outdoor temperatures at night, on-duty personnel can real-time track and transmit water medium temperature variation data on the production site, promptly adjusting the operating fans and minimizing the number of fans in operation. Over the past week, the number of operating fans has halved, resulting in a corresponding 50% reduction in electricity consumption.
