The famous factories for the steel plates are JINAN Steel、, ANSHAN STEEL、 SHA STEEL The Third Steel. These pipe mills can produce raw materials in very good quality. The order specification shall be2000、 2500mm board width and length direction fixed size (double fixed size board).The gas pipes in the production factory shall be checked one by one in the unloading, the content of the check shall be:
a. The length and width of the water pipes shall be consistent with the specification in the delivered material list.
b. The spraying sign material and furnace No. of the petroleum pipes shall meet with the submitted Quality Warranty.
c. Whether the surface of the steel plate have the defect such as concave pit, interlayer etc.
d. The water pipes must be piled in order in separate according to the specification and wall thickness when they are entering in the factory. It is forbidden to pile in disorder.
It shall conduct the sampling inspection on the welding wire, welding flux, welding rod in the first supply by the supplier. It especially must carry on the chemical analysis on the supplied welding wire and inspect that its every chemical component is whether to meet the need of the demanded material. The longitudinal welded pipes material quality of the project is S355. Its selected welding wire sign by the welding is H08MnA. The welding flux sign matching with welding is SJ301（10～60 items）.All the welding material must enter into the welding material warehouse in type, and shall carry on the management and baking by the special person. The baking of the welding rod and welding flux shall master some quantity, and it shall be baked following the use, and shall not bake over the used quantity. It is forbidden to distribute and use the linepipe and water pipe in insufficient baking temperature.
For API gas pipe, it carries on the physical and chemical test on the sample of the raw material by the different specification and furnace No.. On the base, it shall conduct the trial welding by establishing the welding test plate. The petroleum pipe such as the establishment of the welding groove, welding current, voltage and speed see Welding Process Review Guideline in detail. After the test part is welded, it will conduct the ultrasonic inspection, the test part welding seam quality appraisal standard is CSA W59-03.The qualified test part after the welding seam inspection, it conducts the physical and chemical analysis and test on the welding joint, carries on the chemical analysis on the welding joint, and tests on the tensile, bending and impact of the joint. After its every index reaches the national standard requirement, it can confirm the Longitudinal welded pipe qualified welding process and carry on the welding phase.