Venting system that can reduce risks under runaway reactions was one of the most economical and effective measures. The study of pressure mathematical model provided necessary parameters for vent calculation

and helped engineers design more reliable venting system by understanding pressure tendency. Moreover

this model supported to calculate vent area in different filling ratios with less experiment. The ARC (accelerating rate calorimeter) test of 20%DTBP (di-tert-butyl peroxide) was chosen as the standard test. Combined with theory

the mathematical model of pressure in closed container was first deduced

which was suitable for adiabatic condition. Then

according to the comparison between adiabatic corrected test data and model simulated data

the correctness for this model was verified. Combined with Leung method

vent calculation was carried out with the model pressure simulation data. From the calculation

the vent area reached its maximum

while the filling ratio equaled 20%. The established closed container pressure model was correct and reliable. Furthermore

this model can be applied to the calculation of vent area.