This fourth in a series of eight modules for a course titled Mechanical Inspection describes the classifications of pipe and fittings, the types of connections used in the installation of piping systems, the typical marking schemes, the preinstallation and installation verifications, and the tests of the completed installation. The module follows a typical format that includes the following sections: (1) introduction, (2) module prerequisites, (3) objectives, (4) notes to instructor/student, (5) subject matter, (6) materials needed, (7) procedures, (8) data table, (9) reference materials, (10) test. (The course is one of fifteen technical courses for the second year of a two-year postsecondary curriculum in Nuclear Quality Assurance/Quality Control Technology.) (LRA)