Hitachi YUTAKI S80 Series - Water Piping; Domestic Hot Water Hydraulic Circuit; Hydraulic Circuit

18 PMML0291A rev.2 - 09/2014
WATER PIPING
5 WATER PIPING
5.1 DOMESTIC HOT WATER HYDRAULIC CIRCUIT
5.1.1 Hydraulic circuit
Nature No. Part name
Accessories
1 Security water valve unit (DHWT-SWG-01)
2 Water check valve (ATW-WCV-01)
Field
supplied
3 Recirculation pump
4 Shutoff valve
5 Drain
Factory
supplied
6 Heating coil
7 Heating coil outlet water pipe (accessory)
8 Heating coil inlet water pipe (accessory)
9 DHW outlet water pipe (accessory)
10 DHW inlet water pipe (accessory)
Water ow Union Nut
Heating coil inlet
(From the indoor unit)
Main DHW
inlet
DHW
DHW Tank
Optional recirculation
(Security valve detail)
Pressure relief valve
Draining
Check valve
Shut-off valve
Main DHW
inlet
Heating coil outlet
(To the indoor unit)

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 sup-
plied (10) (pressure setting 7 bar. The security water valve
provides:
- Pressure protection
- Non-return function
- Shut-off valve
- Filling and emptying functions
- Draining
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
1
6
4
3
5
2
Security water valve
(DHWT-SWG-01)
NOTE
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 (eld supplied): one (4) must be connected
after the DHW outlet water pipe factory supplied (9) in order to
make easier any maintenance work.