Generally speaking, the diameter of spiral steel pipe can be divided into outer diameter, inner diameter and nominal diameter. The outer diameter of a
spiral steel pipe is represented by the letter D, followed by the outer diameter size and wall thickness. For example, a seamless steel pipe with an outer diameter of 108 and a wall thickness of 5MM is represented by D108*5. Plastic pipes are also Expressed by outer diameter, such as De63, others such as reinforced concrete pipes, cast iron pipes, galvanized pipes, etc. are expressed by DN. In design drawings, nominal diameter is generally used to express it. The nominal diameter is artificially specified for the convenience of design, manufacturing and maintenance. A standard, also called nominal diameter, is the specification name of a pipe (or pipe fitting).
The nominal diameter of the pipe is not equal to its inner diameter and outer diameter. For example, there are several types of spiral steel pipes with a nominal diameter of 100MM, such as 102*5, 108*5, etc. 108 is the outer diameter of the pipe, and 5 represents the wall thickness of the pipe. Therefore, the inner diameter of the steel pipe is (108*5-5)=98MM, but it is not exactly equal to the difference between the outer diameter of the steel pipe minus twice the wall thickness. It can also be said that the nominal diameter is close to the inner diameter, but not equal to the inner diameter. A specification name for the diameter of a pipe. The nominal diameter is used in design drawings. The purpose is to determine the structural dimensions and connection dimensions of pipes, pipe fittings, valves, flanges, gaskets, etc. based on the nominal diameter. The nominal diameter is represented by the symbol DN. , if the outer diameter is used in the design drawings, a pipeline specification comparison table should also be made to indicate the nominal diameter and wall thickness of a certain pipeline.
How to achieve energy saving in spiral steel pipes for transporting fluids
The conveying fluid pipe took advantage of the seasonal changes in the temperature drop in late autumn and took measures to reasonably start and stop the cooling tower operating fan and the axial flow fan used for cooling in the pump room, effectively reducing power consumption. According to calculations by the professional management department, this alone can reduce costs by nearly 100,000 yuan per month. In daily production operations, 15 cooling tower fans (sets) are running at full load at the same time, with a total power of up to 1,600kW per hour, making it a veritable power consumer. Since the steelmaking system and continuous casting system have special requirements for the supply of water medium, especially when smelting fine steel types, the control of the temperature difference of the water medium plays a vital role in stabilizing product quality and developing new steel types.
In addition, the changes in outdoor temperature can be used to reasonably start and stop the fan to achieve the purpose of reducing power consumption and saving energy. Actively contact each production line user point to gain an in-depth understanding of the specific requirements for water temperature, determine the most reasonable range, and achieve the purpose of reducing costs and increasing efficiency while meeting production needs. Make full use of the characteristics of seasonal changes and the decrease in outdoor temperature at night, and adopt the method of real-time tracking and detection of the temperature change data of the water medium at the production site by on-duty personnel to adjust the operating fans in a timely manner to minimize the number of operating fans. Over the past week, the number of operating fans has been halved, as has power consumption.
Static pressure bursting strength of spiral welded pipe
Through relevant comparative tests, it was verified that the measured values of yield pressure and burst pressure of spiral welded pipes and straight seam welded pipes are basically consistent with the theoretical values, and the deviations are close. However, whether it is yield pressure or burst pressure, spiral welded pipes are lower than straight seam welded pipes. The blasting test also shows that the circumferential deformation rate of the blast hole of the spiral welded pipe is significantly greater than that of the straight seam welded pipe. This confirms that the plastic deformation ability of spiral welded pipes is better than that of straight seam welded pipes, and the blast opening is generally limited to one pitch. This is because the spiral welds play a strong role in constraining the expansion of the crack.
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