9. Refrigerant and water piping
TCGB0075 rev.0 - 11/2012
109
9
Hydraulic necessary elements
The next hydraulic elements are necessary to correctly perform the domestic hot water circuit:
•
1 Security water valve (DHWT-SWG-01 accessory)
: this Hitachi accessory (1) is a pressure and temperature relief
valve that must be installed as near as possible at the DHW inlet connection before the DHW inlet water pipe factory
supplied (10) (pressure setting 7 bar; temperature setting 90ºC). The security water valve provides:
-
Pressure protection
-
Non-return function
-
Shut-off valve
-
Filling
-
Draining
1
6
4
3
5
2
Ref.
Name
Main inlet water (DHW inlet)
DHW inlet connection
Pressure relief valve and manual empty
Emptying connection (drain pipe)
Water check valve (non return)
Shut-off valve
Security water valve
(DHWT-SWG-01)
N O T E
The discharge pipe should be always open to the atmosphere, free of frost and in continuous slope to the down
side in case that water leakage exists.
•
1 Shut-off valve (field supplied)
: one (4) must be connected after the DHW outlet water pipe factory supplied (9) in
order to make easier any maintenance work.
Hydraulic optional elements
In case of a recirculation circuit for the DHW circuit:
• 1 Recirculation pump (field supplied): this pump (3) will help to correctly recirculate the hot water to the DHW inlet.
•
1 Water check valve (ATW-WCV-01 accessory): this Hitachi accessory (2) is connected after the pump (3) in order to
ensure the non-return of water.
• 2 Shut-off valves (field supplied): one (4) before the pump (3) and one (4) after the check valve (2) in Shut-off valve
(field supplied).
N O T E
lf the domestic cold water entry pressure is higher than the equipment’s design pressure (6 bar), a pressure redu
-
cer must be fitted with a nominal value of 7 bar.