Abstract: A system for controlling sand discharge from a plurality of sand separators each of which has a dump line and an actuated valve apparatus in the dump line. There is a first controller which is operatively connected to the actuated valve assemblies and is configured to open one of the actuated valve assemblies in response to a parameter such as internal pressure in the sand separator. There is a second controller which is connected to the first controller and which is also connected to an actuated discharge valve in a common discharge line to which all of the dump lines are connected. On a command from the first controller to the second controller that a selected one of the actuated valve assemblies is opening, the second controller opens the discharge valve.