Damping device for check valves

Claim 1

Damping device for a check valve in liquid lines having a closure member movable by liquid flow and disposed on a flap seat in closed condition of the valve, and a damping unit with throttling surfaces separated from respective surfaces of the flap seat, the damping unit including a pair of opposing damping elements in the form of a cylinder and a piston with a piston plunger, on the one hand, and a stop for the piston plunger, on the other hand, one of the damping elements being connected to the closure member, and the other of the damping elements being connected to the flap seat, the cylinder being formed with a chamber wherein the piston with the piston plunger is longitudinally movably mounted so that the piston plunger extends out of the chamber and is engageably with the stop just before the closure member reaches the position thereof in which the valve is in the closed condition thereof, thereby moving the piston within the cylinder chamber, the chamber being closed nearly on all sides thereof and being filled with liquid, and a restoring spring disposed between the piston and a base location of the cylinder so as to exert a force on the piston plunger in direction toward the closure member, comprising arm means for holding the damping element connected with the flap seat centrally within the interior of a liquid line, the cylinder chamber having a cross section increasing toward the side thereof facing toward the stop.