Without a doubt, whether the metric is net margin or balance sheet, the most profitable construction companies are full service type, providing“design, engineering, project management, construction and procurement” in the heavy industrial and civil sectors. You can contact Ningbo Salvador Piping System Co., Ltd.,Shanxi Jingdong Pipe Industry Co., Ltd.,Hangzhou Jiuyang Plastic Pipe Industry Co., Ltd.,Shanghai Ali-Mama Steel Trading Co., Ltd.,Tianjin Fuxiang Steel Pipe Manufacturing Co., Ltd. via the red button for more infomation.