Quality Inspection Methods For Flat Gasket Metal Wound

- Nov 06, 2017-

Quality inspection methods for Flat Gasket metal wound
Flat Gasket is generally used in high temperature and pressure situations. These workplaces are of high quality for Flat Gasket. Once leaks occur, they often have serious consequences. For the petrochemical industry, the quality of the metal wrapped Flat Gasket should be highly valued. Metal Winding Flat Gasket quality problems mainly in the compression rate and rebound rate in two aspects. Compressibility is one of the key metrics for measuring the quality of a Flat Gasket wrapped around a metal. If the compression ratio is too high, it can cause structural damage and can not accommodate normal installation prestress. If the compression ratio is too small, you will need to apply a larger installation prestress, which can not achieve the designed seal effect under normal installation prestress. If the Flat Gasket does not have a good spring-back rate, it can not be fully reset after the load is unloaded. Flat Gasket rebound rate has a more compensatory ability, but also has a better sealing effect. Therefore, the quality inspection of the metal wrap Flat Gasket, the main is to examine Flat Gasket compression rate and rebound rate of these two key indicators.
In the metal wrap Flat Gasket for testing, according to the following ways:
①According to the inspection index of Flat Gasket performance, we choose the three indexes of rebound rate, compression rate and leakage rate to measure the comprehensive performance of a certain type of Flat Gasket.
② Select Flat Gasket seal performance analysis indicators will spring rate, compression rate and leakage rate as variables, respectively, as the source of variance, statistical calculation of the sum of squared deviations, degrees of freedom, mean square, F ratio and significance level;
③ selected evaluation indicators should be based on the corresponding national standards to travel, such as GBT4622.3-2007 in a variety of types of winding Flat Gasket compression rate, rebound rate, leakage rate made the corresponding classification and regulation, refer to These normative data to make a preliminary assessment;
④ Experimental methods Select different angle of the strip and radial compression as a variable, statistical changes in the sealing performance under the different combinations of these two variables, and calculate the corresponding square of the variance and deviation and the degree of freedom, the mean square , To calculate the significance level under different combinations (preferably a = 0.01) with the F distribution, and then determine whether to seal the flat gasket at the significance level of a = 0.01 according to the national standard;
⑤ For the same type of metal wrapped Flat Gasket, are using the above test steps, combined with sampling and testing theory, can be a comprehensive assessment of this type of Flat Gasket wrapped around the quality.
According to the statistics of engineering equipment, 60% -70% of the routine maintenance construction projects of stationary equipment are related to Flat Gasket leakage, especially to the winter season with low temperature. Flat Gasket leak problem is even more troubling. Now the metal wrap Flat Gasket leak rate related issues such as analysis and discussion.
Bolt Flange Flat Gasket connection system is a prestressed static indefinite system, the deformation of the system must be consistent, and to ensure that a certain amount of pre-stress and operating pressure. Engineering practice shows that leakage is the main form of connection failure. Compressive stress and leakage rates are calculated for a specific flanged system and for a specified service condition, the leakage index that the system can achieve, and the Flat Gasket compression load. The concrete method is to combine the mechanical properties and sealing performance of the metal-wrapped sheet by the coordination analysis of the deformation of the connection system. By combining the traditional and isolated Flat Gasket coefficient and the pre-stress ratio, Tightness analysis.
The relationship between the medium pressure, the residual compressive stress and the leakage rate of the rigid flange and the real flange is compared by choosing a certain prestressing force and the same relevant parameters; and for different performance parameters of the same kind of nonmetallic filler Flat Gasket metal winding simulation.

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