... China and abroad. Zhejiang Nanhua Steel Tube Manufacturing Co.,Ltd is located in the famous business city of Wenzhou ... clients.The products widely used in petroleum,chemical industry,chemical fiber,medical machinery, smelting,aerospace,papermaking,foodstuff ... ,boiler,heat-exchanger ,pressure containers,water resources and electricity industry etc. Executed standard of products: ASTMA269/ ASTMA312 / ...