Lunor Explosion Barrier Sanitary blast Valves are designed to for use in primary sanitary ventilation pipes, such as ones used for water or oil. The SB-100 protects the shelter from destruction by external pressure and wake waves. Function: Pressure and following wake waves enter the ventilation system through the external openings, which forces the SB valve to close in a fraction of a second, allowing only a very small and harmless part of the energy to enter in. The SB valve acts in two directions. It works against the pressure from the surrounding area entering in the shelter and works against the wake wave in the opposite direction. Normally the valve is open and allows air to circulate freely for ventilation purposes. The housing is made of cast aluminum. All inner parts are made of chrome steel to resist corrosive destruction caused by vent gazes. Lunor SB valves are tested on a reflecting pressure of 10 bar and are Certified by the Swiss Federal Office of Civil Defense.