An East Coast utility needed a line stop to replace a butterfly valve on a 30-inch cooling water line. The line was located in a constricted area with numerous elbows, and little room for a straight run of pipe for performing the line stop. Team engineers calculated the 30-inch line stop could be completed through the side of a 30-inch, 90° elbow. The elbow was joined by a 19¼" straight run of pipe into the side of a 30" - 45° elbow. To crosscheck their calculations, Team engineers constructed this test fitting to duplicate the exact configuration of the constricted area where the line stop would be made. A hot tap was made on the test fitting utilizing patented Hot Tap Services equipment to test-plug the line where the line stop head entered into the 30-inch 45° elbow. Based on the test results, Team modified the line stop head. Equipment was transported to the job site and the line stop was completed successfully.