Economizer is a heat exchanger device that captures the "lost or waste heat" from the boiler's hot stack gas. The latest technology boiler spiral finned tubes economizer typically transfers this waste heat to the boiler's feed-water or return water circuit, but it can also be used to heat domestic water or other process fluids Our enconomizer is squeezing by high frequency welding method and the technology of steel strip according to certain structure automatically, continuous spiral welding outside the light tube wall, and then the other reserved part light tube bending, combination according to the requirement. As a result, the diameter and length under the same conditions, it has larger heat transfer area.