Hydraulic Circuit; Pressure Drops - Hitachi DHWT Serie Manuel D'installation Et De Fonctionnement

1 Hydraulic circuit

12
12 HYDRAULIC CIRCUIT
When Piping connections are performed:
1 Connect all pipes as close as possible to the unit, so that dis-
connection can be easily performed when required.
2 It is recommended to use flexible joints for the piping of water
inlet and outlet, so vibration will not be transmitted.
3 Whenever possible, sluice valves should be installed for water
piping, in order to minimise flow resistance and to maintain
sufficient water flow.
4 It is recommended to apply ball valves in both water pipe con-
nections to make easier any maintenance work.
5 Proper inspection should be performed to check for leaking
parts inside and outside the system, by completely opening
the hot water inlet and outlet valves to the water condenser.
6 This DHWT must be fully air purged to avoid heating elements
radiating the tank case without water.
7 Apply thermal insulation on the hydraulic system pipes in or-
der to avoid accidental injure due to excessive heat on piping
surfaces and also to avoid heat losses.
8 When the unit is stopped during shutdown periods and the
ambient temperature is very low, it is possible that the water
in the pipes and in the circulating pump freeze, thus dama-
ging the pipes and the water pump. In order to prevent this,
during shutdown periods it is useful to empty the water from
the installation.
N O T E
Check periodically:
• Water flow and pressure
• Water leakage's
• Fixing points tightening
C A U T I O N
Inlet and outlet connection pipes must be 1G"
It must be kept the water flow direction indicated in previous
drawing.

12.1 PRESSURE DROPS

DHWT(200/300)E-2.5H1E
500
200
100
50
20
10
5
0.2 0.5
0
16 PMML0198A-rev.1 - 04/2011
All manuals and user guides at all-guides.com
2 5
1 10
C m
=
p
DHWT(200/300)(E/S)-2.5H1E
5
8
1 Sanitary safety valve unit
2 Non-return valve
3 Circulator
4 Recirculation pump
5 Shutoff cock
6 Drain
7 Drain valve
8 Heating coil
DHWT(200/300)S-2.5H1E
500
200
100
50
20
10
5
0.2 0.5
0
3 /h
H.S.W.
5
Recirculation
4
2
5
7
5
Input
Return
5
1
Mains
water input
6
2 5
1 10 C m
=
p
3 /h