Shandong Hengtong Expansion Joints Manufacturing Co., Ltd. is located at the foot of the mountain Tai, which is the head of the five mountains "World Double Inheritance". We are a large-scale enterprise which specializes in designing, researching, developing and manufacturing expansion joints of corrugated pipes. We have "People's Republic of China Special Equipment (pressure piping component) Manufacturing Permit", and passed ISO9001 quality control system certification. Our "multi-corrugation (containing single-corrugation) thick wall...