More than 65% of the factories buy pipes from small factories, price about 5% cheaper. These pipes don’t have even wall thickness, the result is the fittings wall thickness will go below the minus tolerance requested by standard. Moreover, fittings made from these pipes may have defects, such as lamination, external spirals, cracks and other problems. After grinded, these defects are invisible; but there is big risk during service.
Another 35% of the factories buy used pipe, wasted pipes, broken pipes or pipe ends to produce fittings. Price about 20% lower. For example, while nickel and chromium qualify, carbon seriously exceeds the standard. Fittings made from these materials are not qualified: neither chemical composition nor mechanical properties are good. For this reason, the fittings may fail to be welded to pipeline; or fittings are broken easily; or leakage due to invisible defects.
Qingdao CONTUBE only buys pipes from first-class pipe plants in China, such as Tsingshan, Jiuli, Froch, etc. We control fittings quality from the beginning: all pipes are tested and guaranteed excellent physical and chemical properties and even wall thickness.
We supply mill test certificate issued by pipe plants to our clients’ requirement.