Page 280 - 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

Indirect boosting with a pressure vessel

This rather complicated system is used mainly in buildings where a number of
storage cisterns are fed at various floor levels, making it impractical to control
pumps by water level switches. It utilises a pneumatic pressure vessel to
maintain the pressure boost to the higher levels of the building.

The pneumatic pressure vessel comprises a small water reservoir with a cushion of
compressed air. The water pumps and the compressed air operate intermittently.
The pumps replenish the water level and the pressure vessel maintains the
system pressure. Since the system may be supplying drinking water, the vessel
capacity is purposely kept low to ensure a rapid and regular turnover of water. The
compressed air must be filtered to ensure that dust and insects are eliminated.
Pressure switches
Gauge
Supply to high level

Compressor
Pressure
relief valve
Compressed air

Water Sight
gauge
Supply from
break cistern

Duplicate pump set
p Figure 5.29 Auto-pneumatic pressure vessel

Normally, the controls, including the pressure vessel, pumps, air compressor and
control equipment, are purchased as a package, although self-assembly booster
sets are available.

p Figure 5.30 A typical booster set with pressure vessel and control boards
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