Hydrotreating is a process widely used in the petroleum industry for producing high-quality fuels and as part of a scheme for upgrading heavy crude oil by reducing sulfur, nitrogen and/or metal content. It is the reaction of organic compounds with hydrogen, in the presence of a catalyst, to remove unwanted impurities such as sulfur, nitrogen and metals. Hydrotreating units are needed in the refinery to clean streams from material harmful to the catalysts. That is why they are located before the reformer, hydrocracker and FCC, etc. They are also needed to adjust the final product specification for various streams, such as light naphtha, kerosene and low sulphur fuel oils. Some typical hydrotreating processes are naphtha hydrotreating, kerosene hydrotreating, diesel hydrotreating and vacuum gas oil (VGO) hydrotreating. BIH supply furnaces for all of these applications.