Pressure vessels are mechanical devices that act as a reservoir of fluids at pressure more or less than atmospheric pressure. This research focuses on the application of the pressure vessel for hydraulic testing of hydro turbines to maintain uniform velocity profile and to suppress the pressure surge in the pipeline. An initial assumption for the design of a thin-walled horizontal type pressure vessel with the ellipsoidal type of head is based on the mathematical relations as per ASME code, Section VIII, Division I, for an operating pressure of 0.3 MPa and design pressure of 0.6 MPa. The pressure vessel has been placed, close to outlet of the main pump to prevent the water hammering in the pipeline. The measurement of the pressure fluctuations at the inlet, outlet, and inside of the vessel, due to the dynamic action of fluid forced by the pump are recorded. The study attempts to relate the use of pressure vessels to generate stable flow and pressure at the outlet for hydraulic testing of turbines.