The Swedish Defence Research Agency (FOI) has on behalf of and in collaboration with the Swedish Fortifications Agency (Fortv) performed functional testing of blast valves. The tests were performed in shock tube IV at Botele Udd in Märsta, Sweden. The blast valves are constructed to be placed in barriers leading into sheltered areas and are of the type, automatic valves. The purpose of this test campaign was to study specific blast valves and their capability to withstand certain blast loads and still be fully functional. The test objects for this study have been two types of blast valves: PSV-350 and PVKK-6. The PSV-350 blast valve can withstand three blast loads in a row of 2.7 MPa, 15.7 kPas with a duration of 53 ms. At this load, a blast wave is let through with a duration of 3.6 ms, before the valve has fully closed. The PV-KK-6 blast valve can withstand three blast loads in a row of 1.25 MPa, 11.1 kPas with a duration of 54 ms. At this load, a blast wave is let through with a duration of 1.7 ms before the valve has fully closed.