CEA 4001 - Page 133

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p = 0,098h
where:
p is the static pressure difference, in bar;
h is the vertical distance between the points, in metres.
G.1.3 Velocity
The equilibrium water velocity shall not exceed:
6m/s through any valve or flow monitoring device;
10m/s at any other point in the system,
for the stabilised flow condition at the demand point involving an area of operation or where the
system includes intermediate sprinklers the total number of sprinklers assumed to be in simultaneous
operation.
G.1.4 Fitting and valve friction losses
The pressure loss due to friction in valves, in fittings and in couplings where the direction of water
flow is changed through 45° or more, shall be calculated using an equivalent length and
applying the formula specified in G.1. The appropriate equivalent length to be used shall be one of
following:
a) as specified by the equipment manufacturer; tested in a laboratory which is accepted
by the authorities;
b) as taken from Table G2, provided that it is no lower than a).
If there is a bend, tee or cross where there is a change in direction of flow and there is also a
change in diameter at the same point, the equivalent pipe length and pressure loss shall be expressed
in pipe length of the smaller diameter.
G.1.5 Accuracy of calculations
Calculations shall be carried out with the accuracy of measurements given in Table G3.
Furthermore
the following degree of accuracy for calculations shall be adhered to:
x
the algebraic sum of pressure loss in a loop shall equal 0mbar + 1mbar;