YLW series of horizontal, coal-fired, chain grate, thermal oil boiler (also called hot oil boiler, thermal fluid boiler) are used in many industrial applications where efficiency and accurate temperature control between 100-300℃ are required. They work in the way of heating directly thermal fluid in the pipes with the high temperature smoke. With the help of forced circulation oil pumps, the fluid with high temperature goes into the heat-required equipments, like dryer, and then comes back to the boiler and is re-heated again. The shell plate is made of Q235-A%