• Haihao attaches importance to each customer2022-08-30
• Successful docking of nuclear power projects2022-08-29
• Some basic requirements of nuclear power plant pipeline technology2022-08-26
• Development of nuclear power plants and some product details2022-08-25
• Why Haihao Group still stand well in adversity?2022-08-23
• Obtain customer trust, customers place orders2022-08-11
• Complete production and prepare for shipment2022-08-08
• Professional factories win the trust of customers2022-08-03
• Types of galvanized2022-07-26
• The fourth type test-tensile test2022-07-21
• The third type test- flattening test2022-07-21
• The second type test- Low temperature impact test2022-07-13
• The first type test – hydrostatic test2022-07-07
• What is DNV GL certification?2022-07-04
• What is the difference between API 5L PSL1 and PSL2 standards?2022-06-30
• Defects that may occur when pipeline steel pipe is welded2022-06-20
• Function of heat treatment process for flange pipe fittings2022-06-15
• Heat treatment and characteristics of steel2022-06-13
• The ways of heat treatment for seamless and precision pipe2022-06-08
• The heat treatment ways of fittings and flanges2022-06-06