Flap valve with tangential axle - opens at rate set by torsion springs of which tension is adjusted by rotating head of lockable axle

摘要

The pressure actuated flap may be used to control the discharge of a liquid carrying pipe. Torsion springs control the speed at which the flap pivots open, and provide for in situ adjustments of a spring tension. A circular flap (3) covers an opening with a rim seal, having a three pronged head traversed by a tangential fixed axle (4). The flap is free to rotate on the axle at a rate governed by coil springs (5) mounted between prongs, each spring having radial and returns entering bores in the flap and the axle respectively. One end of the axle is locked against rotation by a diametric locking screw (11) entering alternative blind radial bores (10) in an end fitting (9), and including a square head (8) for rotation by a socket spanner. The square head and the screw are accessible in bores which open out on the barrel of the valve body (1), and may be protected by screw plugs (15, 13).