Abstract: A system for controlling fluid flow from an outlet aperture, particularly a standpipe such as a fire hydrant. There is a first cylindrical collar element for location around the standpipe and connected with that element a second cylindrical element such that a space is defined between the two elements. There is a base provided between the two elements and a first outlet pipe for location above the standpipe. When the system is located about the standpipe fluid fills the space and stabilizes the elements relative to the standpipe. Fluid can then be directed away from the area of the aperture in the standpipe through the flexible pipe.