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4 Pipe connections
General
Pipe installation must be carried out in accordance with
current norms and directives.
Internal support bushes should be fitted when a plastic
pipe or annealed copper pipe is used. The water heater
must be fitted with the requisite valves, such as a safety
valve, shut-off valve, non-return valve, and vacuum valve.
An overflow pipe must be routed from the safety valve
to a suitable drain. The size of the overflow pipe must be
the same as on the safety valve. Route the overflow pipe
from the safety valve enclosed along its entire length and
ensure that it is frost proof. The outlet of the overflow
pipe should be visible and clearly away from any electrical
components.
Overflow water from the safety valves goes via non-
pressurised collecting pipes to a drain so that hot water
splashes cannot cause injury. These non-pressurised col-
lecting pipes shall not be used for anything else. A dis-
charge pipe from the tundish connected to the expansion
relief valve (safety valve) shall also be connected to a drain
in the same way.
Please note that the connection of the T&P-valve should
not be used for any other purpose.
Valves may not be positioned between the expansion
valve and the vessel.
Valve outlet size
G1/2
G1/2
G1/2
G3/4
G3/4
G3/4
G1
G1
G1
Hard water areas
Usually, there should not be a problem in installing
VPB/VPBS in areas of hard water as the operating temper-
ature is 50-60 °C.
10
Chapter 4 |
Pipe connections
Minimum size of dis-
Minimum size of dis-
charge pipe
charge pipe from
tundish
15 mm
22 mm
15 mm
28 mm
15 mm
35 mm
22 mm
28 mm
22 mm
35 mm
22 mm
42 mm
28 mm
35 mm
28 mm
42 mm
28 mm
54 mm
Discharge pipes from tundishes shall have av vertical
section of pipe at least 300 mm long, before any elbows
or bends in the pipework (see following picture).
Metal discharge pipe from
temperature relief valve to tundish.
Safety device
600 mm maximum
(e.g. temperature
relief valve).
300 mm
minimum
Metal discharge pipe from tundish,
with continous fall.
NOTE
The expansion vessel accomodates expansion
that results from heating the water inside the
unit. The expansion vessel must be connected
between the expansion valve and the cylinder.
The location of the expansion vessel should allow
access to recharge the pressure as and when
necessary.
Maximum resistance
allowed, expressed
as a lenght of
straight pipe (i.e. no
elbows or bends)
up to 9 m
up to 18 m
up to 27 m
up to 9 m
up to 18 m
up to 27 m
up to 9 m
up to 18 m
up to 27 m
Cleaning the climate system
When the water heater and the climate system have been
filled with water, VPB/VPBS must operate at maximum
normal temperature for at least one hour. Thereafter the
system must be drained of water and refilled.
Tundish
Discharge below
fixed grating.
Fixed grating
Trapped gulley
Possible wall
Resistance created by
each elbow or bend
0.8 mm
1.0 mm
1.4 mm
1.0 mm
1.4 mm
1.7 mm
1.4 mm
1.7 mm
2.3 mm
VPB/VPBS UK
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