Load loss adjustment for ventilation installation

摘要

The load loss adjustment system comprises a casing (8) with an inlet orifice (11) and an outlet orifice (12). A flap valve (14) is mounted inside the casing which pivots about an axis (15) adjacent to the inlet orifice. The valve is returned towards its closed position by a return mechanism (20) which exerts a couple on the valve which varies inversely with the degree of valve opening. The return mechanism comprises a lever (21) and two pivoted rods (23,25). This assembly is pivoted at one end to the casing and at the opposite end pivoted to the lever. The assembly is attached to a return balance weight (27).