A technique facilitates controlling fluid flow in a well system or other flow related system. The control of fluid flow may be accomplished by utilizing a flow control valve which is selectively actuated via the controlled application of an actuating fluid. An isolation valve is positioned along the flow of actuating fluid at a location upstream of the flow control valve. The isolation valve establishes a preset pressure which is applied to establish flow of actuating fluid to the flow control valve and also isolates detrimental pressure transients. For example, the isolation valve may be used to reduce or block the propagation of detrimental pressure transients along the actuating fluid to other controlled devices.