Page 328 - 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

Terminal fittings

Terminal fittings are those that are fitted to sanitary appliances, such as baths
and washbasins. There are several different types, which are:
● Pillar taps for baths, washbasins and bidets – these are available for baths
(¾-inch tails), washbasins and bidets (½-inch).
● High-necked pillar taps for kitchen sinks – similar internal design to pillar
p Figure 5.98 Pillar taps taps but designed with a high stem to provide an AUK3 air gap at kitchen
sinks.
● Bi-flow mixer taps including monobloc mixers – these are two taps in a single
body. A bi-flow mixer has a single spout that is divided down the middle so
that the water does not mix until it has exited the tap. It is not a true mixer
tap.
● True mixer taps – allow the hot and cold water supplies to be mixed inside
the body of the tap. Caution should be exercised as these taps can provide a
cross-connection between low-pressure hot (fluid cat. 2) and high-pressure
cold (fluid cat. 1).
p Figure 5.99 Bi-flow mixer taps ● Bib taps and hose union bib taps – bib taps are mostly fitted to the wall
above cleaners’ sinks and Belfast sinks. Hose union bib taps are specifically
designed for garden use so that a hose may be connected.
They fall into three categories:

1 taps with a rising spindle to BS 1010
2 taps with a non-rising spindle to BS 5412
3 ceramic disc taps.
p Figure 5.100 True mixer taps
Taps with a rising spindle to BS 1010
BS 1010-type taps have a rising spindle attached to a jumper plate and a
washer. When the tap is turned on, the spindle rises, allowing the pressure
of the water to push the jumper plate and washer upwards to start the flow
of water. Originally, there were two different types:
1 those taps with loose jumper plates for high-pressure supplies such as mains
cold water
p Figure 5.101 Bib taps 2 those taps with fixed jumper plates for low-pressure supplies such as indirect
cold water installations and vented hot water supplies.

Both types have a packing gland designed to stop water leaking through the
spindle. The design of BS 1010 taps is generic across most manufacturers. This
means that the head workings of one tap will almost certainly fit the tap body
of another manufacturer, including stop tap heads.

BS 1010 taps are available as stop taps, pillar taps for washbasins and bidets,
high-necked pillar taps for kitchen sinks, mixer taps for baths (¾-inch thread)
and kitchen sinks (½-inch thread), and bib taps.

316

9781510416482.indb 316 29/03/19 8:59 PM