Question 1

How can water usage be minimised in domestic hot and cold water systems

Accepted Answer

A)  Provide all water outlets from high level storage tanks
B)  Throttle pipe circuit balancing valves to minimise maximum water flow rates
C)  Use spray taps on washbasins, low flow shower heads, dual flush toilets and urinal occupancy sensors
D)  Reduce washing and toilet facilities to below recommended numbers C

Question 2

What does central domestic hot water storage system mean?

Accepted Answer

A)  Domestic hot water storage cylinder with pipework distribution to all hot water taps
B)  Hot water storage tank in the middle of a building
C)  Centrally heated storage calorifier
D)  Gas-fired storage water hearers A

Question 3

Domestic potable cold water must not be allowed to rise above which temperature?

Accepted Answer

A)  25oC
B)  10oC
C)  15oC
D)  20oC A

Question 4

Which is the residential domestic hot water storage requirement in litres at 65oC, per person?

Accepted Answer

A)  5
B)  30
C)  15
D)  40

Question 5

Which water description is correct about hard water?

Accepted Answer

A)  High pH value
B)  Occurs in granite rocky soil parts of the country
C)  Total dissolved salt concentration of over 100 ppm
D)  High suspended salt concentration

Question 6

An hotel has 100 double bedrooms, requires 35 litre of domestic hot water storage per guest in an indirect cylinder heated from 11oC to 65oC in 6 hours. What is the exact heater power consumed?

Accepted Answer

A)  17.5 kW
B)  36.7 kW
C)  73.25 kW
D)  52500 W

Question 7

Which of these is the correct basic safety provision for the public mains water supply system?

Accepted Answer

A)  Stop valve as mains water enters each building
B)  Air gap beneath every ball valve and tap outlet
C)  Backflow preventer valve on each mains water pipe entering a building
D)  Ball valve on a cold water storage tank

Question 8

What is a domestic hot water circulation system called?

Accepted Answer

A)  Draw-off circulation system
B)  Personnel circulation
C)  Hot water pipe system
D)  Tap circulation
E)  0

Question 9

Which is the normal domestic hot water storage temperature?

Accepted Answer

A)  55oC
B)  40oC
C)  50oC
D)  65oC

Question 10

Which is the minimum allowable pressure of a water main in the street?

Accepted Answer

A)  10000 kPa
B)  100 bar
C)  10 atmospheres
D)  30 m water gauge
E)  0

Exam 8: Water Services