Views: 0 Author: Site Editor Publish Time: 2020-08-03 Origin: Site
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 indicated by the letter D, followed by the size and wall thickness of the outer diameter. For example, a seamless steel pipe with an outer diameter of 108, with a wall thickness of 5MM, is represented by D108*5. Plastic pipes are also It is expressed by the outer diameter, such as De63. Others such as reinforced concrete pipes, cast iron pipes, galvanized pipes, etc. are expressed by DN. In the design drawings, the nominal diameter is generally used. The nominal diameter is artificially specified for the convenience of design, manufacture and maintenance. A standard, which is also the nominal diameter, is the specification name of the pipe (or 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, 108 is the outer diameter of the pipe, and 5 is the wall thickness of the pipe. Therefore, the inner diameter of the steel pipe is (108*5-5)=98MM, but it is not exactly 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 kind of pipe diameter specification name, so the nominal diameter is used in the design drawings. The purpose is to determine the structural dimensions and connection dimensions of pipes, pipe fittings, valves, flanges, gaskets, etc. according to the nominal diameter. The nominal diameter is represented by the symbol DN If the outer diameter is used in the design drawings, a pipe specification comparison table should also be made to indicate the nominal diameter and wall thickness of a certain pipe.
How to realize energy saving in conveying fluid spiral steel pipe
The conveying fluid pipe catches the seasonal changes of the temperature decrease in late autumn, and adopts reasonable measures to start and stop the cooling tower operation fan and the axial flow fan used for cooling in the pump room to effectively reduce the power consumption. According to calculations by professional management departments, this alone can reduce costs by nearly 100,000 yuan per month. In daily production and operation, there are 15 (sets) cooling tower fans running at full load at the same time, with a total power of up to 1600kW per hour, which is a veritable power consumer. Because the steelmaking system and continuous casting system have special requirements for the supply of water medium, especially when smelting high-quality steel, the control of the temperature difference of the water medium plays a vital role in stabilizing product quality and developing new steel grades.
In addition, the change in outdoor temperature can be used to reasonably start and stop the fan to achieve the purpose of reducing power consumption and saving energy. Proactively get in touch with each user point of the production line, deeply understand the specific requirements of the 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 seasonal changes and the characteristics of outdoor temperature reduction at night, adopt the method of real-time tracking and detection of water medium temperature change data transmitted by the staff on duty at the production site, timely adjust the running fans, and minimize the number of fans in operation. In the past week, the number of fans in operation has been halved, and power consumption has also been reduced by half.
Static pressure blasting strength of spiral welded pipe.
Through relevant comparative tests, it is verified that the yield pressure of spiral welded pipe and longitudinal welded pipe is basically consistent with the actual and theoretical values of burst pressure, and the deviation is close. But whether it is yield pressure or burst pressure, spiral welded pipe is lower than that of straight seam welded pipe. The blasting test also showed that the circumferential deformation rate of the spiral welded pipe blasting port was significantly greater than that of the straight welded pipe. This proves that the plastic deformation ability of spiral welded pipe is better than that of straight seam welded pipe, and the blast opening is generally limited to one pitch, which is caused by the strong restraint effect of spiral weld on the expansion of the crack.