Carbon steel flange blind flange with the rapid development of domestic foreign minister pipeline construction, pipeline pressure test become an indispensable important link, in the before, during and after the test must be conducted for each section of the pipeline ball sweep line, generally for 4 ~ 5 times. Especially after the pressure test, pipeline inside water is very difficult to clean, cleaning the number will be more. In the closed ball using repeated construction method of welding head, its existing problems: one is to increase the Labour strength of workers; 2 it is repeated welding consumables high head method, need more large equipment, the cost is high. For long distance pipeline pressure test to pass the ball after the scanning line, at the serve by repeated welding head method of high labor intensity big, consumables, need more large equipment, the problem of high cost, this paper proposes a new simple quick opening large blind flange plate construction method. The construction method of this article introduces the structure of the fast-opening blind, work steps and intensity. Through application on acerbity NingLan gas transmission pipeline engineering, prove fast-opening blind construction method than repeated three times welding head construction methods to improve work efficiency, not only reduce the labor intensity of workers, and reduce the cost. Carbon steel flanges need to do some preparation work before measurement, measurement, according to certain way and method to determine the different measurement methods, according to the specific situation to ensure the accuracy of the measurement.

To introduce the following carbon steel flange measurement: measure the preparation work before the:

1. According to the large flange position before measurement, should first sketches, equipment each connecting large flange and numbered consecutively, so that the fixture installation to the number, according to certain way and the principle for installation, ensure the normal use.

2. Because when installed, the carbon steel flange diameter is different, possible hi-lo (different), the thickness of the gasket is not equal, so the processing of fixture should correspond to the side of the carbon steel flanges are not interchangeable, thus measurement by size and number is the key to the fixture processing and installation

3. The measurement, it is best to arrange three, two of them were measured, proofread and fill out a form, measuring tool use vernier caliper, if there were no conditions available outside calipers and steel ruler. Measurement is a careful work, is the precondition of fixture installation, measure and record must be prepared to correct, when completing this form must be clear. Seriously to each other in the actual measurement to cooperate, can according to the principle of the right to cooperate and use.