Oil and natural gas are an inseparable part of today's modern life. Oil and gas provide raw materials of many products we use in our daily life from electronic equipment and clothing to medicines and detergents. One of the essential components in the processing of oil and gas is heat exchanger. Different types of heat exchangers with various capacities, characteristics and grades, are widely used in the oil and gas industry, including production and refining of oil, production, sweetening and refining of gas, liquefaction of gas for producing LNG, and etc. In the field of oil and gas, High reliability and optimal heat transfer are two important factors in the design and construction of heat exchangers which if satisfied will result the safe and efficient operation of the plant (oil refinery, gas refinery, and etc.).