Abstract: A flowline protection system includes a first and second isolation valve connectable to a fully rated pipeline to prevent the flow of fluid through the fully rated pipeline when either of the isolation valves are in a closed position, interrupting the flow of fluids to a downstream underrated piping system to reduce the risk of overpressure or quantity of hydrocarbon released into the environment in the event of a line break. First and second hydraulic control assemblies each include high and low pressure safety pilot valves. Both the isolation valves return to the closed position if either high pressure safety pilot valve senses an operating pressure greater than a high pressure setting or if either low pressure safety pilot valve senses the operating pressure is less than a low pressure setting. The system is self-contained and free of a connection to any component other than the fully rated pipeline.

Abstract: A flowline protection system includes a first and second isolation valve connectable to a fully rated pipeline to prevent the flow of fluid through the fully rated pipeline when either of the isolation valves are in a closed position, interrupting the flow of fluids to a downstream underrated piping system to reduce the risk of overpressure or quantity of hydrocarbon released into the environment in the event of a line break. First and second hydraulic control assemblies each include high and low pressure safety pilot valves. Both the isolation valves return to the closed position if either high pressure safety pilot valve senses an operating pressure greater than a high pressure setting or if either low pressure safety pilot valve senses the operating pressure is less than a low pressure setting. The system is self-contained and free of a connection to any component other than the fully rated pipeline.