CEA 4001 - Page 49

49
Table 11 :
: Minimum water volume for precalculated HHP and HHS systems
Design density not exceeding
mm/min
Minimum water volume
m
3
Wet systems
Dry systems
7,5
10,0
12,5
15,0
17,5
20,0
22,5
25,0
27,5
30,0
225
275
350
425
450
575
650
725
800
875
280
345
440
530
560
720
815
905
1 000
1 090
8.3.2.2 Calculated systems
The minimum water volume shall be calculated by multiplying the maximum demand flow by the following
operating
times:
- LH 30 minutes
- OH 60 minutes
- HH 90 minutes
8.3.3 Refill rates for full capacity tanks
The water source shall be capable of refilling the tank in no more than 36 hours.
The outlet of any feed pipe shall be situated at least 2,0m away from the pump inlet, measured horizontally.
8.3.4 Reduced capacity tanks
The following conditions shall be met for reduced capacity tanks:
a) the inflow shall be from a town main and shall be automatic, via at least two mechanical float
valves;
b) the effective capacity of the tank shall be no less than that shown in Tables 12;
c) the tank capacity plus the inflow shall be sufficient to supply the system at full capacity as
specified
in 8.3.2;
d) it shall be possible to check capacity of the inflow;
e) the inflow arrangement shall be accessible for inspection.