Valve reverse for ventilation: appearance and scope

The reverse valve for ventilation is aimed at eliminating the reverse airflow in the ventilation systems , if the fan is turned on. When the ventilation system is turned off, it is impossible to allow the passage of outdoor cold air through the duct of the hood, in addition, it makes it possible to protect the ventilation against penetration of gnats, dust and other things.

The reverse valve for ventilation can be installed vertically or horizontally, depending on what tasks are before it. If it is installed in an upright position, then it is important to take into account that the air flow should have a direction from the bottom up. When installing horizontally, it is important that the flow rate is more than six meters per second, and for vertical installation, more than four meters.

The reverse valve for ventilation has the form of a blade mounted on the axes and placed in the housing. A cylindrical counterweight is attached to the axis, allowing to hold the blade in the closed position when the fan is on, allowing to open as smoothly as possible when the air flow starts to move. The valve connecting flanges are provided with a number of standardly positioned holes intended for its rigid placement in the duct or pipe.

A check valve for ventilation, the price of which is quite affordable, can be one of two types: to have a section in the form of a circle or a rectangle. The most common round variant is of the "butterfly" type. It is a construction on the axis of which a pair of petals are fixed, which divide the valve into two parts. Air can pass only in one direction, since the petals are specially sprung for this purpose. If the flow is directed back, then they close. In this case, there is one significant drawback: the probability of wedging due to frost in one of the positions is high.

The air check valve for ventilation can be used in household exhaust systems. Sometimes an extract in the bathroom from the neighboring apartments seeps an unpleasant smell. In this case, an excellent way out of the situation may be to install a hood with a non-return valve. It does not allow air from the ventilation shaft to enter the room if the fan is off. When it is turned on, the airflow to the mine will be released.

As a check valve, an inertial grate is often used, which is installed from the outside. Its device is oriented to the possibility of opening the blinds in only one direction, so when the hood is turned off, it will close. It is worth noting that some operating conditions may cause even an inertial grating to stick. This factor should be taken into account when designing ventilation. With the right approach to this issue, you can achieve an excellent result.

Thus, the reverse valve for ventilation can be made in the form of a conventional device of a fairly simple design, or in the form of an inertial grating. Belonging to a particular type assumes special conditions for mounting the device.