Water Flow Control - Hitachi YUTAKI S80 R410A Series Installation And Operation Manual

• Ensure that the installation complies with applicable legislation in terms of piping connection
and materials, hygienic measures, testing and the possible required use of some specific
components like thermostatic mixing valves, Differential pressure overflow valve, etc.
• The maximum water pressure is 3 bar (nominal opening pressure of the safety valve). Provide
adequate reduction pressure device in the water circuit to ensure that the maximum pressure is
NOT exceeded.
• Ensure that the drain pipes connected to the safety valve and to the air purger are properly
driven to avoid water being in contact with unit components.
• Make sure that all field supplied components installed in the piping circuit can withstand the
water pressure and the water temperature range in which the unit can operate.
• YUTAKI units are conceived for exclusive use in a closed water circuit.
• The internal air pressure of the expansion vessel tank will be adapted to the water volume of
the final installation (factory supplied with 0.1 MPa of internal air pressure).
• Do not add any type of glycol to the water circuit.
• Drain taps must be provided at all low points of the installation to permit complete drainage of
the circuit during servicing.
5.3.5 Water flow control
YUTAKI pumps can estimate the water flow by electronic calculation. Therefore, there is no need to
install a water flow switch with the new YUTAKI pumps.
However, if a secondary pump is installed, it is necessary to install a water flow control, as the
electronic calculation may be affected.
PMEN0648 rev.0 - 03/2023
5
35