A method and apparatus for phased array ultrasound testing of piping that complies with present-day codes but allows more thorough flaw detection capability. A tapered wedge with a concave face is calibrated by submerging the wedge under sonic coupling fluid, thereby allowing sonic coupling of the concave wedge face to a flat reference plate with minimal error. The flaw detector is configured to display A-scan and S-scan data concurrently and to sweep between 30-70 degrees. A-scan data corresponding with conventional preferred inspection incidence angle is selected, and reject levels are set to 0% to meet current inspection standards. S-scan data allows for detection of flaws that might otherwise be undetectable using only A-scan data. A palette adjustment feature remaps the colors assigned to lower intensity return values so that they are not displayed on the S-scan, thereby de-cluttering sectorial data without filtering A-scan data.