High pressure experiments were done to determine the pressure effect on multiphase induced forces. To that end, a series of water/gas, oil/gas and oil/water/gas vibrations measurements were performed at 10, 25, 45 and 80 bar at different liquid and gas rates in a horizontal, 2″, double Uloop test section installed at the Equinor Porsgrunn site. At higher pressures the vibration amplitude decreased inversely proportional to the pressure. This was measured for both oil and water. Based on the vibration data, the forcing spectrum was reconstructed. In this the same decreased trend was observed, indicating that a changed damping is not the cause of the reduced vibrations. In the forcing spectra the main effect was a higher energy content at lower frequencies. No clear shift in the peak frequency was measured.