Underground shut-off valve with a hinged flap

摘要

An underground shut-off valve comprises a housing (1) defining an axial flow passage (6) for fluid flow in an axial direction (7) between a first opening (4) and a second opening (5) of the housing (1), the valve further comprising a flap (8) having a front side and a back side, the flap (8) being hinged for movement around a first hinge axis (10), the first hinge axis (10) being arranged within the valve housing (1), outside the flow passage (6), and extending transversely of the axial direction (7) such that the flap (8) may be swung between an open position away from the flow passage (6) and a closed position where the flap (8) closes the flow passage (6) fluid-tight by means of a seal provided between the flap (8) and a cooperating valve seat, wherein the valve further comprises inside the housing (1) in a control chamber (33) communicating with the flow passage (6) a lever mechanism configured to act upon the backside of the flap (8) for controlling the flap movement and for locking the flap (8) in the closed position, the lever mechanism being linked to a spindle drive (13) for operation with a spindle (14), the spindle (14) extending from the inside to the outside of the housing (1). The lever mechanism comprises a locking lever (19), a proximal end (20) of the locking lever (19) being hinged to the housing (1) for movement around a second hinge axis (23) arranged outside the flow passage (6) substantially parallel to the first hinge axis (10), and a distal end (21) of the locking lever (19) being configured to engage the back side of the flap (8) by friction coupling so as to wedge the locking lever (19) against the backside of the flap (8).