Page 151 - water-controls-for-public-and-commercial-places
P. 151

Solutions for thermostatic mixing valves /


        4. SIZING THE APPROPRIATE PREMIX
                                                                                               Chart of PRESSURE
                                                                                               LOSSES:
        The choice depends on the design corrected flow rate and pressure loss.                 Dynamic pressure drop
                                                                                               when operated under
        1. Select the PREMIX size depending on design corrected flow rate for mixed water in the system.  varying flow rates.

        2. Check the PREMIX pressure loss.                                                     REMINDER: Check
          Having established the dynamic pressure at the thermostatic mixing valve inlet and the required residual   pipework pressure
          pressure for supplying installation, select the model chosen based on the associated pressure drop.   losses (e.g. different
                                                                                               floor levels, extended
        Example:                                                                               supply pipes, etc.).
        For a 50 lpm design flow rate:                                                          See chapter "Sanitary
        The PREMIX ¾" records a 2.4 bar pressure loss as opposed to 0.9 bar for the PREMIX 1".  technical data"
                                                                                               (page 269).
        NB: When supply pressure is 3 bar (recommended), pressure loss should not exceed 1 bar.
                                                                                               Due to the diversity
                                                                                               of fittings possible,
                                                                                               this information is
                                                                                               not contractual and
                                             PREMIX          ¾"       1"     1¼"    1½"        is for guidance only.
            3                                                                                  The designer remains
                                                                                               responsible for
                                                                                               determining the best
            2
                                                                                               simultaneity coefficient
            1.5                                                                                and TMV model.
            1 0.9                                                                                                     THERMOSTATIC   MIXING VALVES
          Pressure drops  P in bar  0.6
            0.8
            0.7
            0.5
            0.4
            0.3


            0.2




            0.1
                3   4  5  6  7 8 910       20     30   40  50 60 70 80 100      150  200
                                             Flow rate in lpm



































                                                                                      Thermostatic mixing valves  149
   146   147   148   149   150   151   152   153   154   155   156