In this research, we described the behavior of the valve by a mathematical model of the discharge pressure valve and then we studied the vibrations frequency of the hydraulic system which has plotted the pressure in a short period of piston pump in absence and in presence of discharge pressure valve. The results of this study showed special vibrations frequency relationship of the discharge pressure valve and hydraulic system where this relationship could decide the effectiveness of the protection system before loading. It also showed that dynamic pressure factor in absence of discharge pressure valve is j1=110% while the presence of the valve is j2 = 20%.