CALEFFI 521312TM, Installation, Commissioning And Servicing Instructions

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Operating Limits
I ) For the manufacturer’s limits in terms of flow rates, pressures and temperature, refer to the
manual code ......
II ) For optimum performance, dynamic supply pressures should be nominally balanced to
within 10% of the lowest inlet pressure. Avoid draw-offs from hot water or cold water outlets
immediately before the inlets of the thermostatic mixing valves as they can create an
imbalance in the dynamic inlet pressures.
a) When necessary, utilise a pressure limiting valve or pressure reducing valve on the
common cold water inlet to the heater and to the cold inlet to the mixing valve to equalise
the hot and cold water pressures. AS 3500.1.2 recommends maximum static pressure
of 500 kPa.
b) When necessary, utilise adjustable pressure reducing valve on the hot and cold water inlets
to the mixing valve to equalise the inlet pressures. When dynamic pressures are unequal,
the minimum flow rate must be such that the pressure ratio does not exceed 6:1.
c) Any pressure reducing valve to be used with hot water should be suitable for use with hot
water at the maximum operating temperature.
Pressure ratio
This pressure ratio is calculated as:
Hot dynamic inlet pressure/Cold dynamic inlet pressure or
Cold dynamic inlet pressure/Hot dynamic inlet pressure
The maximum dynamic pressure ratio is 6:1
Pressure ratios outside the maximum allowed must be avoided because the ability of the valve
to control the mixed temperature within tolerance will be affected. If the requirements of the
Hosplan Code of Practice for Thermostatic mixing valves are met (balanced pressures within
10% of the lowest value), then the working conditions of the valve are within 6:1 pressure ratio.
Installation and servicing special notes
I ) These service instructions must be read in conjunction with the manual code .....
II ) Allow a minimum of 70 mm clearance above the temperature adjustment spindle to enable
removal of the internal regulating components
III ) For typical installation diagram, refer to page 108 figure N°4 “Hosplan Code of Practice for
Thermostatic mixing valves”.
IV ) For special conditions regarding Health care installation in hospitals and nursing homes,
refer to “Hosplan Code of Practice for Thermostatic mixing valves”.
V
) For the preparation of commissioning report, refer to appendix 2 and 3 of “Hosplan Code
of Practice for Thermostatic mixing valves”.
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F. istr. 38650_5213 9-07-2007 14:04 Pagina 14