The non-return valve is intrinsically safe 400х400

Intrinsically safe non-return valves are designed for automatic closing of the passage section of the air duct when the fan is turned off in order to prevent the flow of air through the air ducts in the reverse direction.

The valves consist of a body with two flanges, inside which a vane is eccentrically installed on two semi-axes, freely rotating in supports. A counterweight is installed on one of the half axes of the damper, which keeps the blade in the closed position when the fan is not working. The valve blade opens under the influence of the air flow and automatically returns to its original position (closes) in case of cessation of air supply. When the fan is turned on, the counterweight ensures smooth opening of the valve at the beginning of the movement of the air flow.

Valves can be used in ventilation systems with a pressure of 4500 Pa and an air movement speed of 15-20 m/s. Non-return valves can be installed both on horizontal and vertical sections of air ducts. When installing on vertical areas, the direction of air movement should be from the bottom to the top.

In order to exclude sparking, the parts of the valve that come into contact with each other during operation are made of dissimilar metals, namely, the blade is made of ferrous metal, and its contour is made of aluminum. Brass bushings are installed in the friction points of the axis and the body.