Preparation for carbon steel flange measurement

　　With the rapid development of domestic and foreign pipeline construction, the carbon steel flange blind plate has become an indispensable and important part of the pipeline pressure test. Before and after the pressure test, each section of the pipeline must be cleaned by passing the ball, usually 4-5 times. Especially after the pressure test, it is difficult to clean the water stored in the pipeline, and the cleaning times will be more. The construction method of repeatedly welding the head at the ball receiving place has the following problems: first, increasing the labor intensity of workers; Second, the repeated welding head method has high consumables, requires many times of large-scale equipment and high cost. In view of the problems of high labor intensity, high consumables, many times of large-scale equipment and high cost caused by the repeated welding head method at the launching point when the ball cleaning is carried out after the pressure test of long-distance pipeline, a new simple quick opening large-scale flange blind plate construction method is proposed. Before the measurement of carbon steel flange, certain preparations shall be made, and the measurement shall be carried out according to certain ways and methods. Different measurement methods shall be determined according to specific conditions to ensure the accuracy of measurement.

　　Preparation before measurement:

　　1. before measurement, according to the position of the large flange, the sketch of each connecting large flange of the equipment shall be drawn and numbered continuously, so that the fixture can be installed in a certain way and principle to ensure normal use.

　　2. during installation, the carbon steel flange may have different outer diameters, staggered joints and unequal gasket thickness, so the machined fixture should correspond to the carbon steel flange on the side and cannot be interchanged. Therefore, measuring the size and number of each part is the key to fixture processing and installation

　　3. when measuring, it is better to arrange three people, two of whom measure, one of whom proofreads and fills in the form, and the measuring tool is vernier caliper. If there is no condition, the external caliper and steel ruler can be used Measurement is a meticulous work and a prerequisite for fixture installation. Measurement and recording must be prepared without error and the form must be filled out carefully and clearly In the actual measurement work, we should cooperate with each other and be able to cooperate and use according to the correct principle.