Hitachi SAMURAI CLG2, Manual, Page: 32 / 118

Installation
Technical Catalogue
TCGB0051 rev 0 - 09/2009
32
6.2. Water Piping
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When Piping Connections are performed (condenser: In case of water-cooled type):
1. Connect all pipes as close as possible to the unit (condenser: In case of water-cooled type), so that
disconnection can be easily performed when required.
2. Connect the condenser and water coolers in the same unit to the same common water piping.
3. It is recommended for the piping of the chilled water inlet and outlet that flexible joints be utilised, so that
vibration will not transmit.
4. Whenever permissible, sluice valves should be utilized for water piping, in order to minimize flow
resistance and to maintain sufficient water flow.
5. Proper inspection should be performed to check for leaking parts inside and outside the system, by
completely opening the condenser and chilled water inlet and outlet valves to the condenser and water
cooler.Additionally, equip valves to the inlet and outlet piping.Equip an air purge cock and a drain cock
on the water piping. The cock handle should be removed so that the cock can not be opened under
normal circumstances. If this cock is opened during operation, trouble will occur due to water blow-off.
6. Sufficiently perform insulation to keep the chilled water piping cool and to prevent sweating of the piping.
7. Under the condition where the ambient temperature is low in winter, there is a case where equipment
and piping will become damaged during the shutdown periods at night, because the water in the pump
or piping will be frozen. To prevent freezing of the water, it is effective to operate the pumps even during
shutdown period.
HITACHI Chiller has the pump ON/OFF operation control (see Wiring Diagram) water from piping.
Additionally, in a case where measures such as water draining are difficult, utlize antifreeze mixture of
ethylene glycol type or propylenen glycol type.
8. The common water pipes (Inlet/Outlet of condenser and cooler, field supplied, should be connected to
condenser and cooler directly.

CAUTION:
- Never use an antifreeze mixture of the salt type, because it possesses strong corrosion characteristics, and
water equipment will be damaged
- This product is equipped with plate type heat exchangers. In the plate heat exchanger, water flows through a
narrow space between the plates. Therefore, there is a possibility that freezing may occur if foreign particles or
dusts are clogged. In order to avoid this clogging, provide a 20 mesh water strainer at the inlet of condenser and
chilled water piping near the product. A 20 mesh water strainer is available as an option.
Chiller
Water Outlet
Water Inlet

Pressure Gauge

Strainer

Flexible Joint

Valve

NOTE:
HITACHI chiller has the pump ON/OFF operation control (see wiring diagram)