A check valve for a fluid system includes: a valve body defining an inlet, an outlet, and an interior cavity; a closing member positioned inside the interior cavity, the closing member movable between an open position, providing fluid communication between the inlet and outlet, and a closed position, isolating the inlet from the outlet; and a buffer mounted on the closing member, the buffer configured to hold a portion of fluid in the fluid system and cushion movement of the closing member from the open position to the closed position.