The experiments were performed on safety discharge of gas explosions in a vessel with a vent duct. Pressure variations and the flame development in the duct during the ducted vented explosion process were studied. The influence of initial pressure on the venting process was analyzed. Comparative study of confined explosions

simply vented explosions and ducted vented explosions were conducted. It is shown that peak pressure and the rate of pressure rise increase with the initial pressure for isolated closed explosion. For simply vented explosion

with the increase of initial pressure

the peak pressure increases first

then reduces

and finally increases. For ducted vented explosion process

higher initial pressure results in higher peak pressure

higher rate of pressure rise

higher positive pressure difference

and higher flame speed in duct entrance

and explosion intensity in the vessel is more sensitive to the change of initial pressure. Compared to closed explosion and simply vented explosion

with the increase of initial pressure

the difference between peak pressure for ducted vented explosion process and that for simply vented explosion is getting larger

while the difference between the peak pressure for ducted vented explosion process and that for closed explosion is getting smaller

with the rate of pressure rise obviously higher than that for closed explosion.