As one of the tests to detect the performance of the metal compensator, the pressure test is mainly used to test the tightness of the metal compensator weld and the bearing capacity of the metal bellows. Before the compensator leaves the factory, the manufacturer will carry out pressure test on it, and it can leave the factory after passing.
The bellows were straightened because the fixed bracket was not set or the procedure was wrong when the user performed the pressure test on the metal compensator after the installation. The usage is affected. It is recommended that users consult the manufacturer to understand the steps before the pressure test.
Before knowing the method, you should know the requirements to be met by the test. All welds of the metal compensator shall not leak under 1.5 times the design pressure. The change rate of U-wave and ω-wave distance is less than 20%, and there is no obvious change in the structure. According to the structure, it is divided into non-constrained type and constrained type, and the two form methods are slightly different.
During the test, both ends of the metal compensator are fixed and sealed effectively, and its initial state should be in a straight line state. It should be noted that the fixed bracket, guide bracket and fixed support before the pressure test meet the installation requirements, and should be fixed firmly, and the pressure test should be carried out after confirmation. During the test, the pressure should be slowly boosted. When the pressure reaches the test pressure, attention should be paid to observe whether the bellows have plane instability and column instability, and whether the metal structural parts have cracking and deformation. It is recommended to use two pressure gauges with the same range. When one of them is faulty, it can be found in time to avoid the phenomenon of over pressure or not reaching the test pressure.
The specific method of the pressure test of the metal compensator needs to be confirmed according to the specific working conditions, and the manufacturer of the compensator needs to be consulted in advance for the segmented test.