a flow control device is comprised of a body / connector , a simplified sliding cord , a sealing device , and a stopper . the body / connector connects an overhead sprinkler to a supply line by means of male threaded ends . the body / connector is comprised of a wrench connector , which is located between the two male threaded ends , a guiding tube that sits on the top side of the body / connector with the assistance of the supporting ribs . the guiding tube guides the sliding cord up and down inside the flow control device and sprinkler . the sliding cord is made from a material that is flexible enough to bend inside the supply line and strong enough to return to its original straight shape . the stopper and the sealing device are connected to each other with the sliding cord . the sealing device sits against the sealing surface of the body / connector if the sprinkler head is missing . the stopper prevents the sealing device from making contact with the body / connector during normal operational conditions .