CEA 4001 - Fully Calculated Systems

141
T
Table 50: Range pipe diameters of HH installations with pressure and flow characteristics as given in table 7 (3
or 4) (G14)
Range pipes
Layout
Diameter
mm
Maximum number of
sprinklers
fed by pipe
Ranges at remote en of
all distribution pipes
Other ranges
End-side, last 3 ranges
40
50
65
32
40
50
65
1
3
6
1
2
4
6
Ranges at remote end of
all distribution pipes
Other ranges
2 end-centre, last 3
ranges
32
40
32
1
2
2
All ranges
3 and 4 end-centre
32
40
50
1
2
4
G.2.5.5 The pressure loss between the design points and the control valve set shall be
determined by calculation. The pressure loss with the flows shown in Table 8, plus the necessary
pressure at the design point plus the static pressure equal to the height difference between the
highest sprinkler and the control valve set shall not exceed the available pressure.
Where the highest sprinkler is upstream of the design point, the portion requiring the higher static head
shall have its own distribution pipe.
NOTE: the pressure loss in the distribution pipes feeding each section of the risk may be balanced
by suitably sizing the distribution pipe.
G.3 Fully calculated systems
G.3.1 Density of discharge
The minimum density of discharge from each area of operation, or the entire protected area, whichever
is the smaller, containing the relevant group of four sprinklers with each water supply or supply
combination available shall be not less than the design density specified in clause 6.
Where possible the density of discharge shall be taken as the total flow in litres per minute from a
group of four sprinklers which are most closely adjacent, divided by the area in square metres
covered by the four sprinklers. Where fewer than four sprinklers are in open communication, the
density of discharge shall be taken as the lowest value of the flow from any sprinkler divided by the
area covered by the sprinkler.
The area covered by each sprinkler shall be defined by the centre lines drawn midway between