The helical type corrugatedtube, which is approved by UL(USA), RWTUV(Germany) and is certified as a quality product with NET, KS(KSD3628) by the Korean government, is the ideal product for a heat exchanger.The plate pincoil for a heat exchanger is expensive as its manufacturing process is very complicated, and is apt to corrode. Hence, it is increasingly replaced by the helical type corrugated tubes for a heat exchanger developed by Dong-A, which has a narrow-pitch, and a higher peak. (Product specifications are subject to the customers'...