Page 264 - Water_Controls_for_Public-Commercial

/ 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 WCs
URINALS
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: The multiply the gross flow rate (Q) with the simultaneous
coefficient (Y) in order to determine the probable flow rate.
A figure A B
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 WCs
15 basins 6 urinals 12 WCs
Simultaneous coefficient
2. Calculate the design flow rate per installation branch
For direct flush, follow recommendation 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 Darius Abacus chart
Reading the DARIUS 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)
262 Sanitary technical data