An apparatus for gravel packing a production interval (42) of a wellbore (32) comprises first and second sand control screen assemblies (56, 58) connected downhole of a packer assembly (46) and a cross-over assembly (40) that provides a communication path (74) downhole of the packer assembly (46) for a gravel packing fluid and a communication path (92) uphole of the packer assembly (46) for return fluids. A wash pipe assembly (66) extends into the first and second sand control screen assemblies (56, 58) forming an annulus (84) therebetween. A valve (70) is positioned within the wash pipe assembly (66) in a location between the first and second sand control screen assemblies (56, 58). The valve (70) is actuatable from a closed position to an open position when the beta wave (100) is proximate the location of the valve (70).