Ferrules

It is a right angled sleeve made of non-ferrous metal mostly of brass or gun metal. It is joined to the opening drilled in the water main with the plug. A tee branch connection off the main is used to connect the service pipe leading to domestic connection. Cross-section of a common ferrule is shown in Figure.

                  Figure  : A Typical Ferrule for Under-Pressure Tapping in a Service Main

The ferrule is having bore not more than 25 mm. Ferrule of 20 mm bore and above is used in mains having internal diameter more than 100 mm.