444 VPB 500 UK
Pipe installation
Warning to the installer!
This installation is subject to building
regulation approval, notify the local
Authority of intention to install.
Pipe installation
No valve should be fitted between the expansion
valve and the storage cylinder.
Valve outlet size Minimum size of
discharge pipe
Minimum size of
discharge pipe from
tundish
Maximum resistan-
ce allowed, expres-
sed as a length
of straight pipe
(i.e. no elbows or
bends)
Resistance created
by each elbow or
bend
G1 / 2 15 mm 22 mm up to 9 m 0,8 m
G1 / 2 15 mm 28 mm up to 18 m 1,0 m
G1 / 2 15 mm 35 mm up to 27 m 1,4 m
G3 / 4 22 mm 28 mm up to 9 m 1,0 m
G3 / 4 22 mm 35 mm up to 18 m 1,4 m
G3 / 4 22 mm 42 mm up to 27 m 1,7 m
G1 28 mm 35 mm up to 9 m 1,4 m
G1 28 mm 42 mm up to 18 m 1,7 m
G1 28 mm 54 mm up to 27 m 2,3 m
Table sizing of copper discharge pipe for common
temperature relief valve outlet sizes
Please note that the connection of the T&P-valve
should not be used for any other purpose.
Hard water areas
Usually, there should not be a problem in installing VPB
500 UK in areas of hard water as the operating tempe-
rature is 50-60 °C.
Cleaning the heating system
When the water heater and the heating system have
been filled with water, VPB 500 UK must operate at
maximum normal temperature for at least one hour.
Thereafter the system must be drained of water and
refilled.
Emptying the system by
1. Open the filling valve and the drain valve for the
heating system.
2. Flush the system for some minute. Watch out for
water splashes from the safety valve.
3. Close the valves and check the stainer.
600 mm maximum
Matal discharge pipe from tundish,
with continous fall.
300 mm
minimum
Tundish
Safety device
(e.g. temperature
relief valve)
Metal discharge pipe from
temperature relief valve to tundish
Possible wall
Discharge below
fixed grating
Fixed grating
Trapped gulley
Pipe installation must be carried out in accordance with
current norms and directives.
The total volume is 496 litres in the waterheater.
The pressure vessel is approved for max 6,0 bar (0,6
MPa) in the water heater and 3 bar (0,3 MPa) in the coil.
Discharge pipes from tundishes shall have an vertical
section of pipe at least 300 mm long, before any el-
bows or bends in the pipework. See following picture.
Copper inserts should be fitted when a plastic pipe or
annealed copper pipe is used.
A discharge pipe must be routed from the pessure relief
valve to a suitable drain. The size of the discharge pipe
must be the same as on the pessure relief valve. The
discharge pipe must be routed downwards to prevent
water pockets and must be frost proof. The outlet of
the discharge pipe should be visible and clearly away
from any electrical components.
