Page 269 - The City and Guilds Textbook: Plumbing Book 1 for the Level 3 Apprenticeship (9189), Level 2 Technical Certificate (8202) and Level 2 Diploma (6035)

Chapter 5 Cold water systems

valve’ is installed, so that the supply to the house can be isolated if necessary
while any repairs are carried out.

Water
treatment
plant

Water mains

Houses and other buildings

p Figure 5.15 Water supply grid system

Methods of connection to the water main
Underneath the road is the water main. The connection for the water supply
to the dwelling is made by a brass ferrule, which is the responsibility of the
water undertaker. The ferrule is a type of shut-off valve that allows the water
supply connection to be isolated for maintenance and repair.
The connection to the water main can be made in a number of ways depending
upon the material from which the water main is made. For instance, if the water
main is made from cast iron, then a self-drilling and tapping machine is used. With
this tool, the water main is drilled, threaded and a ferrule inserted while the main
is still under pressure so that the supply to other properties is not disrupted. If the
main is made from PVCu or cementitious lined asbestos, then a brass strap-type p Figure 5.16 A strap-type ferrule
ferrule is used. water main connection

From the water main to the building
The water supply from the water main into the building comprises two separate
pipes:

1 the communication pipe, owned and maintained by the water undertaker
2 the supply pipe, owned and maintained by the owner of the building.

The communication pipe is installed by the water undertaker from the ferrule on
the water main to the main external stop valve (also known as the boundary stop
valve because it is usually located at the boundary of the property). It incorporates
a gooseneck bend to allow for any settlement of the roadway or pavement. It is
the sole responsibility of the water undertaker to install, repair and maintain the p Figure 5.17 A standard gunmetal
communication pipe and main external stop valve. ferrule

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