A. Unions: Unions shall not be used on concealed piping.
B. Bushings: The use of bushings should be avoided. When necessary to connect two (2) sizes of pipe, a reducing fitting is preferable, but a hexagonal head bushing may be employed if necessary.
C. Swing Joints: Swing joints on concealed piping which are made by the use of combination of fittings shall not be used. This is intended to forbid the use of combination of fittings where useful only to produce flexibility and therefore for convenience in connecting piping. This necessity can be avoided by cutting accurately the length and careful threading, which is essential to good workmanship. The use of fittings for necessary offsets is not forbidden. (Ord. 15.28)