Abstract: Single Wall Carbon Nano-Tubes (SWNT) have novel mechanical properties. Therefore, they are nominated for many applications. Their ability to transfer molecules has been observed and one of SWNT applications which is going to be developed is storing and transformation of fuel molecules in fuel cells for power generation. In this study the passage of a hydrogen molecule through a SWNT and their interactions were studied by a combination of analytical and Finite Element methods. It was seen that molecule passage causes transient vibrations in SWNT due to van der Waals interactions and SWNT attracts and absorbs hydrogen molecule. As the SWNT diameter increases the applied attraction force reduces. Thus, it is possible to use large diameter SWNTs as a Nano-Pipe and SWNTs with small diameter as a Nano-Pump.