The checking procedure of seamless steel pipe before delivery

Seamless steel pipe is divided into general carbon steel, high-quality carbon steel and alloy steel three kinds according to its material, according to the manufacturing method of hot-rolled and cold drawn two kinds. There are many kinds of specifications of seamless steel tubes for all kinds of working pressure of work, so the quality inspection requirements of the installation site of seamless steel tubes are also different. Low pressure (P≤1.6MPa) and medium pressure (1.6MPa (1).Verify the qualified certificate of the manufacturer. The manufacturer must provide the full name, specifications, manufacturing steel, heat number, lot number, chemical composition, the factory inspection records and other raw materials with the arrival time of seamless steel tubes. (2). Visual inspection on the specifications, package, and marking. It shall be equipped with signs, marked with the manufacturer confirmed code, material, seal of quality inspection departments. (3). the appearance checkthere should not be cracks, shrinkage, slag, folding, heavy leather and other defects. (4). The sampling pipe diameter and wall thickness deviation (5). For high pressure seamless steel pipe and alloy steel pipe, in addition to checking the above four items, it still need to do the hardness test. Each batch should spot a pipe, two tensile testing, two impact testing, one crushed or cold bending testing. Factory without flaw inspection report shall be conducted nondestructive testing one by one, and inspection standards should be consistent with the relevant provisions. These seamless steel pipe can be used in the high-pressure pipeline project only when they all pass the tests.