1. Hot and Cold Water Supplies
10% immediate
expansion
solid
(ice)
expansion from 4–100°C
will give about 4% expansion
liquid
Physical change of water
0°C
freezing
point
4°C
maximum
density
100°C boiling point
H2O water
CO2
CO2 O2
dust and gases
added to rainfall
dust
dust O2
CO2
SO2
Section of pipe with evidence of limescale
rainwater falls to the ground as a
weak and dirty acidic solution
Classification of water
example ground conditions
Moorland (CO2 added)
Sandstone (CO2 retained)
Salt (calcium sulphate)
limestone and chalk (calcium carbonate)
CO2 used up to dissolve limestone
very soft water
(acidic)
soft water
(acidic)
Permanent hard
water (alkaline)
Temporary hard
Water (alkaline)
From Plumbing (3rd edition), R.D. Treloar, page 83 Copyright Blackwell Publishing Ltd, all rights reserved:

2. Hot and Cold Water Supplies
750 mm minimum otherwise pipe is to be insulated
meter just in or outside the boundary
boundary wall
doc
stop valve
750 mm
–1350 mm
water meter
pipe duct
WATER
communication pipe
supply pipe
mains services
Cold supply to a dwelling
gooseneck
meter
‘plan view’ of pipe in trench, note pipe laid with slack to allow for ground movement
Frost damage to valve
(causing wastage of water)
Hose connected to a tap without backflow protection (causing possible contamination)
Typical water meter
From Plumbing (3rd edition), R.D. Treloar, page 85 Copyright Blackwell Publishing Ltd, all rights reserved:
Cold water to the consumer

3. Hot and Cold Water Supplies
the highest the water is likely to reach at maximum rate of inflow
air gap
supply float
operated valve
overflow
Type AG air gap
‘O’ ring
(suitable for fluid category 3)
air gap
spring
Direction of flow
valve
kitchen sink
Non-verifiable single check valve
(suitable for fluid category 2)
Type AUK3 air gap
(suitable for fluid category 5)
zone 2
outlet check
valve
inlet check
valve
zone 1
zone 3
outlet
inlet
inlet
service
valves
isolation
valve
outlet
backflow
occurring
isolation
valve
discharge
valve
discharge
outlet valve
‘Flow position’
‘Safety shut-off position’
discharge outlet
line
strainer
Operation of an RPZ valve
tundish maintaining
a type AA air gap
Reduced pressure zone valve
Assembly (RPZ valve)
From Plumbing (3rd edition), R.D. Treloar, page 87 Copyright Blackwell Publishing Ltd, all rights reserved:

4. Hot and Cold Water Supplies
cistern
cold feed to dhw OR
dhw
storage
vessel
cold supply to unvented system of dhw
15 mm
basin
bath WC
15 mm
22 mm
22 mm
washing
machine
sink
basin WC
22 mm
Direct system of cold water supply
Service valve
feed and storage cistern
cold feed to dhw (vented system) 22–28 mm
cold distribution
22–28 mm
fullway
gatevalve
or ballvalve
dhw
storage
vessel
15 mm WC
basin
bath
doc
15 mm
22 mm
22 mm
supply main
washing
machine
sink
basin WC
service
valve
doc
doc
Indirect system of cold water supply
stop valve
Cold water systems
From Plumbing (3rd edition), R.D. Treloar, page 89 Copyright Blackwell Publishing Ltd, all rights reserved:

5. Hot and Cold Water Supplies
screened air
vent
350 mm
min
sleeved vent
25 mm
air gap
mains
supply
insulation
against frost
filtered
overflow and
warning pipe
25 mm
30 mm
insulation
fullway gatevalves
or quarter-turn ballvalve
vent
from
dhw
lids to be fitted
to cisterns
cold
distribution
pipe
cold feed to dhw
mains supply
Cold water feed and storage cistern
filtered
warning pipes
filtered
overflow
pipes
mains
supply
screened
air vents
manifold
cold distribution pipes
coupling cisterns to
allow one to be isolated
washout pipe
(38 mm min dia)
From Plumbing (3rd edition), R.D. Treloar, page 91 Copyright Blackwell Publishing Ltd, all rights reserved:
Cold water storage

6. Hot and Cold Water Supplies
cover
Softened water supply
service
valves
open
time controller for automatic regeneration
service valve closed on
by-pass
Salt compartment
lid
salt level maintained by
householder
waste
pipe
Drinking water supply
prior to softener
overflow
check
valve
Copper casing
Magnetic and chemical water
conditioners
Zinc rings
doc
Base exchange water softener
(complete removal of calcium salts)
stop valve
salts after treatment
with electronic current
Chemical water
conditioner
galvanic cell water conditioner
(electric current produced by electrolytic corrosion)
salts after
Treatment with
chemicals
calcium carbonate binding together
in untreated water, as viewed
through a microscope
Water treatment
Magnetic water conditioner
From Plumbing (3rd edition), R.D. Treloar, page 93 Copyright Blackwell Publishing Ltd, all rights reserved:

7. Hot and Cold Water Supplies
Automatic air release
drinking water header required where storage cistern is of a large capacity
storage cistern
pipeline level switch
float switch
all cisterns fitted with lids, fly screens, etc., to conform with Building Regulations
delayed action ballvalve
supply to height of water pressure in main
float switch
to indicate
low water
level
hydropneumatic
accumulator
pneumatic
storage
vessel
control
box
break cistern
break
cistern
pressure
gauge
duplicated pumps
Pumping set using float swtches
transducer or pressure switches
Typical packaged
pumping set
sensors to indicate low water
Pumping set using
pressure sensing devices
Boosted water supplies
From Plumbing (3rd edition), R.D. Treloar, page 95 Copyright Blackwell Publishing Ltd, all rights reserved:

8. Hot and Cold Water Supplies
sprinkler heads
distribution pipe
19–25 mm
bore
rubber
hose
range pipe
riser
pressure gauges
hose guide
alarm
25 mm
supply
operating
instructions
1.2–1.7 m
Sprinkler system
automatic air
release
750 mm
min
75–100 mm
Relief
discharge
pipe
100 mm
minimum
diameter
Hose reel installation
64 mm
Landing
valve
pressure relief
valve
Fusible link and glass bulb sprinkler heads
fire brigade
inlet
supply to that above
the supply main
Dry riser inlet
wet riser
dry riser
mains supply
break cistern
drain
valve
booster pumps
fire brigade inlet
Wet and dry risers
From Plumbing (3rd edition), R.D. Treloar, page 97 Copyright Blackwell Publishing Ltd, all rights reserved:
Fire-fighting systems

9. Hot and Cold Water Supplies1”
--- 2
BSP thread
valve plug
quarter-turn fullway valve
(for air elimination and
test purposes)
housing
plug
sprinklers
in loft
glass bulb
deflector
1st floor sprinklers
Typical glass bulb sprinkler head
ground floor
sprinklers
flow switch (to prevent
false alarm due to surge)
12 V demand
valve
check
valve
stop
valve
drain
valve
to domestic
draw-off points
quarter-turn
fullway valve
drain valve
supply
mains
Domestic sprinkler system
From Plumbing (3rd edition), R.D. Treloar, page 99 Copyright Blackwell Publishing Ltd, all rights reserved:

10. Hot and Cold Water Supplies
From Plumbing (3rd edition), R.D. Treloar, page 100 Copyright Blackwell Publishing Ltd, all rights reserved:

11. Hot and Cold Water Supplies
vented system shown in which the water is
heated either via a boiler, an electric
immersion heater or gas circulator
thermostat
g.v. or quarterturn
valve
20 amp
heatproof flex
flue
immersion heater
bath
basin
draught
diverter
sink
Direct dhw cylinder
(no heat exchanger coil)
Gas storage heater
boiler
doc
magnesium
anode
vent pipe
cold inlet
hot distribution
pipe
Note: it is possible to have an
unvented system of direct
dhw supply
dipped
cold feed
Instantaneous
system
(multi-point)
baffle in flue
sink
doc
burner
gas
supply
Multi-point heater with
the case removed
Section through gas storage heater
Direct hot water supply
From Plumbing (3rd edition), R.D. Treloar, page 103 Copyright Blackwell Publishing Ltd, all rights reserved:

12. Hot and Cold Water Supplies
f & e cistern
cold feed cistern
vent
cold feed
heat exchanger
bath
basin
hot
distribution
pipe
Indirect dhw cylinder
(note heat exchanger coil)
Single feed cylinder
hot storage
vessel
primary
flow
secondary water
primary return
sink
c.h. flow
boiler
trapped air in upper dome
primary water
c.h. return
doc
Vented double feed indirect
System of hot water supply
cold feed
system filled
(cold)
system filling
bath
basin
Vented single feed indirect
System of hot water supply
primary
flow
system once heated
primary return
The expansion of the primary water is taken up by forcing the air from the upper dome to the lower dome
sink
boiler
c.h. f & r
From Plumbing (3rd edition), R.D. Treloar, page 105 Copyright Blackwell Publishing Ltd, all rights reserved:
Indirect hot water supply

13. Hot and Cold Water Supplies
test lever
Check valve
floating baffle
Combined pressure and temperature relief valve
Pressure
reducing valve
tundish
and air gap
discharge
pipe
immersion with high
Temperature cut out
mains water
supply
Unvented system incorporating an air pocket
Unvented system using
expansion vessel
test lever
to discharge
pipe
temperature
relief valve
Pressure relief
valve
stop valve
mains
water
supply
point to check
and charge up
the pressure
Selection of control valves
found on unvented system
rubber bag
containing the
expanding water
Unvented system using
a floating baffle
Strainer
As the water cools the air pressure forces
the water out of the bag back into the system
high
temperature
cut out
Unvented system incorporating
expansion vessel and primary circuit
Sealed expansion vessel
(system heated therefore bag shown full)
From Plumbing (3rd edition), R.D. Treloar, page 107 Copyright Blackwell Publishing Ltd, all rights reserved:
Unvented domestic hot water supply

14. Hot and Cold Water Supplies
open vent
pipe
450 mm
hot
distribution
pipe
incorrect
one pipe circulation
taking place
correct
(incorporating a
450 mm offset in
the rise of vent)
pump
secondary
flow
Connections to the top of the
hot storage cylinder
bath
basin
basin
Secondary return
Secondary circulation
sink
hydraulic
gradient
drop in
water
levels
water at a state of rest with a ‘no flow’ condition
water flowing from
valve when tap opened
Illustration to identify
the hydraulic gradient
hydraulic
gradient
correct
connection
of tap
All taps opened and a ‘no flow’ situation is indicated at tap ‘X’
(tap ‘X’ will only operate providing no other taps are open)
From Plumbing (3rd edition), R.D. Treloar, page 109 Copyright Blackwell Publishing Ltd, all rights reserved:
Hot distribution pipework

15. Hot and Cold Water Supplies
Rough comparison of time taken
to warm water in cylinder based
on a 17 kW boiler and a 136 litre
dhw storage vessel
hot storage
cylinder
pump
circulating
head
primary
flow
boiler
circulating
head
primary
return
excellent heat recovery
(say 1/2 h)
boiler
boiler
good heat recovery
(say 2 h)
good heat recovery
(say 2 h)
Heat recovery period
From Plumbing (3rd edition), R.D. Treloar, page 111 Copyright Blackwell Publishing Ltd, all rights reserved:

16. Hot and Cold Water Supplies
flue outlet
basin
bath
heat exchanger
combustion
chamber
sink
pilot flame
burner
push rod
thermocouple
Venturi
Gas multi-point
f & e cistern (optional built into unit)
adjustable
thermostatic
mixing valve
overflow
hot
water
outlet
cold water
inlet
gas
inlet
expansion
chamber
pressure differential
valve
thermostatic
valve
boiler
hot
water
outlet
c.h.
flow and
return
to hot taps
cold
mains
supply
to cold taps
dipped cold
feed
cold
mains
supply
flow and return
to c.h.
Combined primary storage
unit (CPSU)
Water jacketed tube heater
Instantaneous domestic hot water supplies
From Plumbing (3rd edition), R.D. Treloar, page 113 Copyright Blackwell Publishing Ltd, all rights reserved:

17. Hot and Cold Water Supplies
Single point gas water heater
View inside a small electric single
point heater
immersion
heater
thermostat
hot outlet as
used above
on appliance
inlet
controlled
section through an electric
single point storage water heater
electrical
element
supply
outlet
controlled
inlet
section through an electric
instantaneous water heater
cold
supply
to tap
specialised design of tap
to allow for the expansion of
water from the storage heater
when installed below the appliance
permanently
open hot
supply and vent
cold
supply
to heater
Localised hot water heaters
From Plumbing (3rd edition), R.D. Treloar, page 115 Copyright Blackwell Publishing Ltd, all rights reserved:

18. Hot and Cold Water Supplies
solar
collector
radiant heat
from sun
air
release
vents
pressure
gauge
gravity check
valve
pressure
relief
valve
air
space
temporary
filling
connection
warm store
vessel
expansion
vessel
double
glazed
cover
doc
double
check valve A
doc
thermal
insulation
outlet
dhw hot
storage cylinder
hot
distribution
pipe
primary
Circuit to boiler
collector
box
section A–A
thermal
insulation A
Typical flat plate collector
Solar hot water system
7From Plumbing (3rd edition), R.D. Treloar, page 117 Copyright Blackwell Publishing Ltd, all rights reserved:
Solar panel

19. Hot and Cold Water Supplies
cold feed connection to dhw to be above
the cold supply to the shower to prevent
scalding
1 m minimum
alternative
connection
shower mixing valve
separate distribution
pipes to shower
‘Essex’
flange
used
hot and cold distribution
to all other appliances
Storage fed shower
150 mm
flow switch
resilient
mounting
strainer
single impeller
booster pump
150 mm
flexible
connections
double impeller
booster pump
Installation of shower
booster pumps
separate vent
check valve
300
min
separate hot and cold
distribution pipes
bidet
air gap
maintained
Bidet with submersible nozzle
Shower booster pump
to remaining hot
and cold supplies
Connections to bidets
Over-the-rim
type bidet
Connections to hot and cold pipework
supply
main
From Plumbing (3rd edition), R.D. Treloar, page Copyright Blackwell Publishing Ltd, all rights reserved:

20. Hot and Cold Water Supplies
backplate
threaded
studding
plastic
spacing clip
screw on holderbat
(school board clip)
double split
munzing ring
saddle clip
two piece
spacing clip L 4
single split
munzing ring
Typical pipe supports
0.07 L H 8 H L 4 H 8
0.4 L L
centre of bearing
centre of bearing
complete
air blockage
Selection of typical pipe clips
used on copper and steel
pipework
partial blockage
of trapped air
cistern
trapped
air
hot storage
cylinder
Common causes of air locks
Installation of pipework 1
From Plumbing (3rd edition), R.D. Treloar, page 121 Copyright Blackwell Publishing Ltd, all rights reserved:

21. Hot and Cold Water Supplies
removable cover
floor screed
Pipes below solid floors
cover
duct
concrete base
this method may only be adopted
where no joints are enclosed and
the pipe can readily be withdrawn
Pipes below timber floors
boards must be removable for inspection of
joints and in all cases inspection available
at 2 m intervals
Pipes under floors
cover
plaster or
tile finish
pipe screwed
to stud with
resilient
mounting
removable
cover
pipe in
chase
timber stud
wall
Pipes within walls
only permitted in an internal wall where the pipe can be
capped off should a leak become apparent
sleeve
e.g. larger
pipe
insulation
(if required)
removal
cover
bath
Pipes located behind
a bath
From Plumbing (3rd edition), R.D. Treloar, page 123 Copyright Blackwell Publishing Ltd, all rights reserved:
Installation of pipework 2

22. Hot and Cold Water Supplies
4.0
cold storage
cistern
main
distribution
pipe WC
3.0
bath
7 m
basin
2.0 WC
3 m
2 m
1.5
3 m
Litres per second
1.0
Loading units
3 m
appliances at
each floor to
be the same
as those on
the highest
level
0.5
3 m
0.4
0.3
3 m
Conversion table
(loading units to litres/sec)
From Plumbing (3rd edition), R.D. Treloar, page 125 Copyright Blackwell Publishing Ltd, all rights reserved:
Pipe sizing of hot and cold pipework

23. Hot and Cold Water Supplies
Flow rate (litres per second)
Pipe sizing of hot and cold pipework
(Reproduced with permission of The Institute of Plumbing and Heating Engineering)
From Plumbing (3rd edition), R.D. Treloar, page 127 Copyright Blackwell Publishing Ltd, all rights reserved:

24. Hot and Cold Water Supplies
rapid up and down ball float movement
damping plate fitted to prevent any
waves forming; alternatively fit a
larger ballfloat
metal plate required on
plastic cisterns to prevent
the cistern wall vibrating
oscillation type noise
tap washer
oscillation
valve to permit vessel
to be charged
charge
of air
should a pressure surge occur
the shock wave is taken up by
the cushion of air
cavitation
scale build up
air
boiler wall
hydropneumatic
accumulator
trapped air within boiler
Flexible connections to
reduce noise from booster
pump
sufficient slot size
Noise transmission in pipework
felt underlay
fitted to notch
From Plumbing (3rd edition), R.D. Treloar, page 129 Copyright Blackwell Publishing Ltd, all rights reserved:

25. Hot and Cold Water Supplies
pipe blanked off with fitting
to allow air to be removed
open ends
blanked off
pressure
gauge
isolating
valve
operating
handle
drain
valve
flow meter
Hydraulic pressure testing
Test for water pressure and flow
Pressure and flow
test equipment
pressure
gauge
Labels secured
to valves as
necessary
Commissioning of hot and cold supplies
From Plumbing (3rd edition), R.D. Treloar, page 131 Copyright Blackwell Publishing Ltd, all rights reserved:

26. Hot and Cold Water Supplies
temporary supply
system to be
disinfected
type AA air gap
check
valve
pump
cistern
supply
pipe
temporary
connection
Temporary connection for dosing mains supplies
From Plumbing (3rd edition), R.D. Treloar, page 133 Copyright Blackwell Publishing Ltd, all rights reserved:

27. Hot and Cold Water Supplies
Operative taking water flow, pressure and temperature measurements
From Plumbing (3rd edition), R.D. Treloar, page 135 Copyright Blackwell Publishing Ltd, all rights reserved: