This overpressure relief valve is critical to creating an overpressure in the protected space by adding the proper, metered resistance to the outgoing airflow. The valve is normally closed and will not open unless the air pressure inside the shelter is slightly greater than the outside air pressure.
This gives you true ventilation – air in through the Safe Cell and out through this valve preventing the buildup of carbon dioxide exhaled by the occupants. Carbon dioxide poisoning will incapacitate and kill the occupants of an enclosed space without ventilation long before oxygen deprivation.
Please specify at time of ordering whether or not you are mounting this valve directly on the wall or ceiling – or if you are going mount it to the blast valve. We will configure your overpressure relief valve so it either has a mounting flange for the wall or ceiling or a slip-fit connection for the blast valve.
A good rule of thumb is that if you are underground, you need blast valves and if you are above ground, you do not – unless you have a hardened structure above ground. There is not much need for blast valves unless you have a hardened, blast resistant structure.
Any protected space will benefit from this valve, especially if it is well sealed, then this overpressure relief valve is a necessity – if you want true ventilation.