4. High-pressure boiler seamless pipe (GB5310-1995) is used to manufacture high-pressure and more pressure on the water boiler heating surface with high-quality carbon steel, alloy steel and heat-resistant stainless steel seamless pipe.

5. Fertilizer equipment high pressure seamless steel pipe (GB6479-2000) is applicable to operating temperature -40 ~ 400 ℃, working pressure of 10 ~ 30Ma of chemical equipment and pipeline quality carbon structural steel and alloy steel seamless steel tubes.

6. Petroleum Cracking Seamless Steel Tubes (GB9948-88) is applied to the oil refinery furnace tubes, heat exchangers and seamless steel pipe.