We started our cooperation with HEIYAN GROUP by purchasing an intermediate frequency power supply. Later, we purchased many pipe fitting machines, both large and small, from HEIYAN. All of them run stably and their after-sales service is also good. One of the most satisfactory suppliers I have found in China. The process of working with Hei Yan has also witnessed the development of our company. I sincerely wish that we can support each other better and longer.