Abstract: A shut-off valve, for use with a sprinkler head affixed to a riser pipe, including a valve seat affixed within the riser pipe upstream from the sprinkler head, the valve seat having an opening and impeding flow through said riser except through the opening. A movable valve element is located within the riser pipe upstream from the valve seat, the valve element being movable between an open position, in which it is spaced apart from the valve seat, and a closed position, in which it engages the valve seat to close the opening and impede fluid from flowing through the riser pipe. A spring biases the valve element toward the valve seat, and a perforated tube extends from the valve element through the opening in the valve seat and contacts the sprinkler head to maintain the valve element in its open position.