Double H fin tube, known as Square fin tube & Fin economizer, is used in boilers, marine ... economizer, H fin tube economizer, H type finned tube, square fin tube.It is a kind of boiler parts, ... Principle:H-economizer two rectangular fin, similar to a square, its edge length for the fluorescent tubes of 2-fold ... ' requirements.Welcome to contact us. Heat Exchanger Fin Tubing (H/double H fin tube)