A four-litre-autoclave was used to perform deflagration tests in a closed vessel. The aim was to investigate the suitability of this autoclave and to evaluate different parameters influencing the deflagration. The validation of test results showed that the autoclave is suited for the performance of deflagration tests. In comparison to tests performed in an open system according to VDI 2263-1 the results are in good agreement. In the closed vessel same characteristics as in the open test were determined. In addition, pressure rise and rate of pressure rise have been determined and used to characterise deflagrations. The influence of sample weight, tube diameter, bulk density, initial pressure and temperature was investigated. Furthermore, the emerging gas amount and the rate of gas evolution were determined and compared with pressure curves. The use of a four-litre-autoclave for performing deflagration tests offers several advantages in comparison to an open test.