Boiler tube quality problems mainly in the cracks, shrinkage, peeling, pit, layered, pinhole, slag and so on. Boiler tube defects and injuries that may exist in the same smelting and rolling process. The main defects in the surface of the boiler tube and an outer surface than the inner surface. About 70 percent of these defects from the raw material (billets), billets in blowing insufficient residual slag material, shrinkage, etc., with which there may be rolled steel transverse cracks, laminated, folded, heavy leather and other defects, longitudinal cracks caused mostly rolling strain. If the boiler tube in the emergence of these defects or injuries, considers the material appeared discontinuous density within the material is damaged, it is possible leaks in the hydraulic pressure test, boiler pressure element is made at run time there may leak or burst pipes. Because of this, in order to ensure the quality of boiler pipe, whether it is related to a foreign country or boiler seamless steel pipe standards are clearly defined, as the process performance guarantee, steel hydraulic test should be made by the root.

The purpose of the hydrostatic test, there are two: one is the process of hydraulic test, its purpose is to test the material (or components) for leaks, that the sealing properties of materials; the other is the verification of the hydrostatic test, its purpose is to strength test material (or components) is adequate. From here, the hydrostatic test pressure boiler tube is part of the process of trial, is the material density test, if the test material is dense and continuous; it is not the strength of experimental verification. Strength theory of mechanics of materials known from, seamless steel components are thin and long, and its diameter is very small, even for thin-walled tubules can withstand a lot of pressure.