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/ Sanitary technical data


                 RECOMMENDATIONS FOR SIZING HORIZONTAL FINAL PIPEWORK

                 In order to determine the simultaneous coefficient, apply the recommendations from the DTU.
                 Supply direct flush systems separately.

                 TABLE 2 / CALCULATION RULES FOR CONSIDERING SIMULTANEITY

                                                                                 SIPHON ACTION
                                         BASINS        SHOWERS       URINALS                             WC
                                                                                    URINAL
                   Base flow rate (Q min.)  0.05 L/sec.  0.10 L/sec.  0.15 L/sec.  0.25 L/sec.           1 L/sec.
                                                                                              3 valves installed:
                                                                                              1 valve operating
                                                                                              4 to 12 valves installed:
                                                                                              2 valves operating
                      Simultaneous        0.8   *        0.8  *        0.8  *        0.8  *   13 to 24 valves installed:
                      coefficient (Y)      (x-1)          (x-1)         (x-1)         (x-1)    3 valves operating
                                                                                              25 to 50 valves installed:
                                                                                              4 valves operating
                                                                                              more than 50 valves installed:
                                                                                              5 valves operating.
                    Design velocity (V)                                    2 m/sec.
                 *The formula presented here is with regards to general use.
                 In the event of intensive use due to spikes in consumption (schools during break time, stadiums during half time, etc.), consult the project manager in order to establish the adequate
                 level of simultaneity.
                 The constant of 0.8 can therefore be increased to a maximum of 2.
                 1.  Collect installation data for each branch        Probable flow rate
                 Example:                                             Then multiply the gross flow rate (Q) with the simultaneous
                  A                     figure A                  B     coefficient (Y) in order to determine the probable flow rate.

                                                                      Gross flow rate (Q)  Simultaneous coefficient (Y)    Design flow rate
                                                                         1.65 L/sec. x        0.8            0.30 L/sec.
                                                                                                (21 1)

                                                                       • CD branch: Direct flush systems
                                                                       Gross flow rate: 1 L/sec.

                                                                                          Branch  Number of fittings
                  D                                              C

                                                                                            CD       12 WC
                        15 basins     6 urinals      12 WCs
                                                                      Simultaneous coefficient
                 2.  Calculate the design flow rate per installation branch
                                                                      For direct flush, follow the recommendations in table 2.
                 Add the base flow rates from the different fittings.   For 12 flush valves installed, there will only be 2 used simultaneously.
                 See Q min. calculation table 2.

                  • ABC branch: basins & urinals                      Probable flow rate
                  Gross flow rate                                       Min. flow rate  Number of valves counted  Probable flow rate
                                   Number of   Min. flow rate  Gross flow rate  1 L/sec. x
                           Branch                                                            2                 2 L/sec.
                                    fittings    (Q min.)     (Q)
                                               0.05 L/sec.
                             AB     15 basins x                      0.75 L/sec.  3.  Choice of pipework diameter:
                                                                         using the DARIES Abacus chart
                                                                      Reading the DARIES ABACUS
                                               0.15 L/sec.
                             BC     6 urinals x                      0.9 L/sec.
                                                                      Mark the design flow rate and the design velocity, join these points
                                                                      with a ruler.
                                             Gross flow rate
                                   21 fittings   (Q min.)     1.65 L/sec.  The diameter and pressure drops can now be read on
                                                                      the corresponding scales.
                 Simultaneous coefficient
                                                                       • ABC branch: basins & urinals
                 To determine the simultaneous coefficient, follow
                 the recommendations in table 2 and apply the formula:  (V) Design velocity = 2 m/sec.
                                                                       (Q) Design flow rate = 0.30 L/sec.
                      0.8
                 Y =                                                   - Ø minimum interior of final horizontal pipework: 14mm
                     (x-1)
                 260 Sanitary technical data
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