Indonesia is a country that has abundant wealth, especially water resources. Many highland areas experience droughts and lack of water resources. Hydram pump is the right solution to overcome drought and get water needs. The hydraulic pump has a high pressure which can cause the conductive valve to be damaged and the air tube pressure unstable. Therefore, a hydraulic pump simulation has been carried out which has been designed using CFD (Computational Fluid Dynamics) software to determine the pressure distribution characteristics that occur in the hydram pump air tube. This study was conducted to determine the pressure distribution characteristics occurring in the hydraulic pump air tube with numerical simulation using academic ANSYS Fluent 19 R2 software. This simulation was carried out on the geometry of the 3-dimensional hydram pump with an 8 inch tube diameter and 7.3 m penstock pipe length. The delivery valve model used in the simulation in the form of a solid cylinder, the delivery valve movement is run using a profile. Simulation on transient conditions with layering dynamic mesh method. Pressure distribution characteristics that occur in the hydraulic pump tube, pressure contour is uneven due to the movement of the transmission valve and there is an outlet in the air tube. The pressure that occurs in the air tube is also affected by the pressure that occurs at the hydram pump body the higher the opening of the delivery valve the pressure that enters the tube increases