Page 577 - 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 9 Sanitation systems

When the handle is depressed, the
flap lifts, allowing water to flow to
the pan by gravity

p Figure 9.26 The operation of a drop valve

The water in the cistern is controlled using a float-operated valve conforming
to BS 1212 Parts 2, 3 and 4. The cistern must also have a service valve fitted INDUSTRY TIP
as close to the cistern as possible. A separate overflow must be installed with
WC cisterns not having an integral overflow, and this must discharge safely in a Float-operated valves and
conspicuous position, usually outside the building. service valves are covered in
detail in Chapter 2, Common
WC cisterns can be made from a variety of materials, including vitreous china, processes and techniques,
plastic and hard rubber, but other materials such as cast iron and lead-lined and Chapter 5, Cold water
wood have also been used in the past. systems.

Washbasins

There is a huge variety of different styles of wash hand basin and many of these
also come in various sizes and tap arrangements. Corner washbasins are also
available. Washbasins should be installed approximately 800 mm from the
floor to the front lip of the basin. Washbasins can be divided into three basic
types:
1 Wall-hung washbasins: this type of washbasin is mounted on wall-fixed p Figure 9.27 A wall-hung
brackets or bolted directly to the wall. There are several different types of washbasin
mounting bracket, including towel rail type or concealed, depending on the
washbasin style. The mounting wall must be able to take the weight of the
washbasin. If there is any doubt, either a centre leg or a pair of legs should be
used.
2 Pedestal washbasins: there are two different types of these:
● pedestal washbasins are fixed to the wall but rely on the pedestal for
their main support; the pedestal is designed to hide the pipework
● semi-pedestal washbasins are becoming increasingly popular; the
pedestal does not carry the weight of the basin as it does not reach the
floor, and is designed to hide the associated pipework.
3 Countertop washbasins: there are several different types of countertop
basins: p Figure 9.28 A pedestal
washbasin
● countertop style washbasins are also known as inset washbasins; they
sit snugly into a worktop surface

565

9781510416482.indb 565 29/03/19 9:05 PM