Abstarct: In a physical view on water hammer problem, rapid shut-down of pumps or sudden closure of valves will cause large amount of pressure rises. Furthermore, it results in local cavities, distributed cavities and excessive vibration of structural and hydraulic systems. Moreover, Heavy impacts will occur if column separation is observed. Explosion of vapor cavities might lead to extensive high pressures which has practical importance in industry. Fluid-structure interaction (FSI) in pipe systems is being focused while the dynamic behavior of the pipe is influencd by water hammer phenomenan. The main goal of the current research thesis is to introduce a numerical model in MATLAB. It should be emphasized that column separation is also included in the solutions. The presented models are pipe systems and also suspended pipes. Then, the results from numerical and experimental observations are being compared. Column separation phenomenan is also modeled applying the so called discrete vapor cavity model (DVCM). The mentioned model is simple and easy to be inserted in the provided program. Finally, it should be added that FSI effects are so important and consideration of column seoeration is recommended seriously. The comparision of results show suitable convergency between the numerical and experimental results