Hitachi YUTAKI S Series Technical Catalogue page 110

8 Refrigerant and water piping
Space heating and DHW
8.3.3 Additional hydraulic optional elements (For DHW)
In case of a recirculation circuit for the DHW circuit:
• 1 Recirculation water pump (field supplied): this water 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 (4) is connected after the recirculation water
pump (31) in order to ensure the non-return of water.
• 2 Shut-off valves (field supplied) (5): one before the recirculation water pump (3) and other after the water check
valve accessory (4).
8.3.4 Additional hydraulic necessary elements for DHW (only for UK market)
The following accessories are necessary for the compliance of the YUTAKI S COMBI for UK market with the UK
requirements referred in the UK Building Regulations 2000.
• 1 temperature and pressure relief valve (factory supplied), fitted at the hottest part of the DHW tank. This device
protects the unit of excessive temperature (>96º C) and excessive pressure (>7 bar) in the DHW tank. Additionally, a
Ø15 diameter pipe (factory supplied)is fitted to the outlet of the relief valve and drives the discharge to the tundish (4).
• 1 tundish(4)(field supplied), installed in a vertical position, with no more than 600 mm of pipe between the valve outlet
and the tundish.
• 1 Tundish outlet pipe (2)(field supplied) with a vetical section at least 300 mm long below the tundish(4), before any
elbows or bends in the pipework. This pipe should be made of metal or other material that has been demonstrated
to be capable of safety withstanding temperatures and pressure of the water discharged, as it is refferred in the UK
Building Regulations.
• The discharge pipe from the tundish (2) must terminate in a safe place where is no risk to persons in the vicinity of
the discharge. the discharge will consist of high water temperature and pressure.
102 TCGB0123 rev.2 - 10/2019
Type Nº
1
Piping connections
2
Accessories 3
4
Field supplied
5
Type Nº
T&P relief valve outlet pipe Ø15
1
(factory supplied)
Piping connections
2 Tundish outlet pipe (Field supplied)
Pressure and Temperature relief valve
Accessories 3
(Factory supplied)
4 Tundish (Field supplied)
Field supplied
5 Drain (Field supplied)
Part name
Water inlet (DHW)
Water outlet (DHW)
Water check valve
(ATW-WCV-01 accessory)
Water pump
Shut-off valve
Part name