Using ASTM A554 standards and national standard toorganize production in order to 201,202,304,316,316 L grooves of rawmaterials welded stainless steel pipe, the surface can be polished,multi-channel products are widely used in petroleum, chemical industry,chemical fiber, metallurgy, medicine, machinery, making paper,insulation refrigeration, mechanical equipment, food, electricity,water, construction, aerospace, submarine engineering, marineshipbuilding, environmental protection and other industries, deeplycustomers.