Page 588 - The City and Guilds Textbook: Plumbing Book 1 for the Level 3 Apprenticeship (9189), Level 2 Technical Certificate (8202) and Level 2 Diploma (6035)

The City & Guilds Textbook: Plumbing Book 1

urinal bowl. The water can be supplied either direct from the water main, from
a boosted cold water system, or by low pressure from a cistern supplied by a
distribution pipe.
Manual valves are lever operated and are located just above the urinal bowl.
Automatic valves are activated via an infrared sensor. The sensor should sense
p Figure 9.60 The hydraulic flush a person for at least ten seconds to prevent accidental activation by someone
control valve
walking by. The sensor activates a solenoid valve and this allows the minimum
short flush.
Automatic flushing valves require a backflow prevention device to be included,
which prevents backflow of fluid category 5 contaminated water.

WC macerators
Macerators use a series of very sharp rotating blades to turn solids into a liquid
slurry, which is then pumped through a small-diameter pipe to a soil stack. They
also offer a solution to installing sanitary appliances where access to the main
soil stack is not practical from a conventional gravity outlet appliance.

Macerators offer the plumber many options when installing sanitary appliances
in remote locations. However, if a WC macerator is installed, Building
Regulations Part G requires that there must also be a gravity WC located in the
same building.

There are many versions of macerators available, some purely for pumping from
p Figure 9.61 WC with a macerator a WC, while others may be used to install entire bathrooms in difficult locations
such as a basement or cellar.

Pump stations used in domestic dwellings

Compact pump systems for small domestic waste water applications are
suitable in situations where foul drainage by gravity is not possible. Larger
domestic pumping stations are recommended for 8 to 13 people, for the
removal of sewage and effluent. They are fitted with an alarm in the event of
high fluid levels.

Waste water lifters used in domestic dwellings
Waste water lifters are used for pumping waste water and sewage from a low
level to a higher level. They are used when it is not possible to remove waste
and sewage from a normal gravity drainage system. They are usually factory-
manufactured units. Key components of waste water lifters include a waste
water treatment receiving well called a ‘wet well’, equipped with lift pumps
and piping with valves, a junction box, and an equipment control panel with an
alarm system.
The installation of a waste water lifter can be below or on the same finished
floor level of a dwelling or premises. The discharge pipework enters the soil

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