摘要 |
The metering valve (24) has a ball shutter (44) for a conical seat (46) over a discharge conduit (43), and an electromagnet (26) for controlling an armature (27); a stem (47) of the armature (27) has a flange (57), is guided by a fixed sleeve (53), and is pushed by a spring (52) to keep the ball (44) in contact with the conical seat (46); provision is made, between the flange (57) and the ball (44), for a decoupling joint (62) in the form of a plate (63) having a flat surface (64) engaging the flange (57) and a spherical concavity (66) engaging the ball (44) to center the ball (44) on the conical seat (46); and the diameter (D) of the concavity (66) is slightly larger than the diameter (d) of the ball (44) to reduce the pressure between the mutually engaging surfaces of the concavity (66) and the ball (44). <IMAGE> <IMAGE> |