... is convenience to install maintain free ball check valve this product uses rubber wrapper grounder as valve clack, under the function of medium ... up and down on unitary slideway of the valve, then open or close the valve. Noise elimination closed, don’t happen water ... 1≤80°1.62.41.76 Main partsParts namematerialValve body, valve deckNodular cast iron, cast ironSphere frame, baffle plateNodular cast iron ...