Air valves are intended for active use in ventilation and air conditioning systems, air heating, as well as in other sanitary systems in which the working pressure does not exceed 1000 Pa. They exist in different forms, on which their specific purpose depends.
Destination
Check valves for ventilation (in the traditional sense) are designed to prevent the flow of fresh outside air through the ducts in cases where the fan stops working. Such devices may have special stops that can be adjusted, which is used to meter the supplied air into the ventilation systems of the premises. It turns out that the non-return valves for ventilation are devices engaged in controlling the air flow due to changes in the area of the duct passageway.
Features of use
Check valves for ventilation have become important and completely indispensable elements of modern systems. They can be locking or regulating. In such devices, there is an urgent need for the cold season, since it is they that protect the room from the penetration of excessively cold air into the room, as well as snow, which can accidentally enter the air ducts. Installing a non-return valve in the ventilation protects against strong drafts characteristic of a cold pore, as well as from the formation of condensation on the surfaces of certain elements. Experts strongly recommend the installation of such valves in emergency smoke ventilation systems, in particular after exhaust and supply system fans . If there are gas installations in the room, installation of such valves is also required. That is, any modern ventilation system in a residential building or at a workplace without fail requires the installation of such devices.
Varieties
Check valves for ventilation come in many types and configurations. Some of them are designed for installation in vertical and some in horizontal sections of the duct. If non-return valves are installed for ventilation in vertical ducts, there is only one requirement: the air direction must be from the bottom up. Such devices can be installed at a speed of advancement of air flows in vertical sections up to 4 meters per second, and in horizontal sections up to 5.6 meters. Reliable and correct operation of the non-return valve is possible only if the air velocity in the ventilation system does not exceed the permissible level of 12 meters per second. The device is built into the system so that during operation it will be completely invisible. Butterfly check valve for ventilation is attached to the ducts through flange connections, which are recognized in this case as the most effective.
Without the use of such devices, the ventilation system is ineffective in the summer, and in the winter it becomes a source of drafts.