... BHP, Rio Tinto and Xstrata material, welding & galvanising QA requirement. Shenzhen Hui Yuan Steel Construct Manufacturing Co. Ltd, a ... BHP, Rio Tinto and Xstrata Material and Welding QA requirement. Most of our products are exported to leading companies ... structures require International Grade welding qualification to fulfil the QA requirement. All of our mining conveyor structure are certified to ...