In refineries heat exchangers are used for the crude oil distillation and subsequent refining stages. Dolphin heat exchangers are used as preheaters, re-boilers, condensers, economizers and as cooler of refined products. In production sites onshore and offshore crude oil is preheated, tanks heated, gas dried and TEG regenerated. A large percentage of the market for heat exchangers is served by the shell-and-tube heat exchanger. Apart from Oil industries Shell and tube Heat Exchangers are widely used in many industrial areas, such as power plant, chemical engineering, food processing etc.