Abstract: A valve assembly having a valve seat, and a valve tappet that moves relative to the valve seat. A stop member for limiting the stroke of the valve tappet. The valve tappet includes an elongated shaft having a reduced mid-section for the purpose of increasing flexibility. The stop member for the valve tappet is a flexible ring-shaped element which functions like a spring washer. As a result of the shape of the valve tappet and of the stop member, any sudden excessive forces or stresses occurring during the opening and closing of the valve are partially suppressed by the elastic characteristics to avoid damage to the valve assembly. The energy-absorbing features avoid breakage of the shaft and eliminate deformation of the valve piston and the stop member in the area of the stop communicating surfaces, and also reduce damage to the sealing surfaces between the tappet head and the valve seat.