FCU 500, FCU 505 · Edition 02.17
52
Valve proving system
The calculation module can be used to calculate the
opening time t
L
for the bypass valves (e.g. VAS 1 or by-
pass valves with additional orifice) by entering the gas
type, calorific value, density, capacity, inlet pressure
and orifice diameter.
Set the next lowest value for parameter 59 to set the
opening time, see page 112 (Valve opening time 1
t
Calculating the extended valve opening time
Gas type
Lower calorific value
Density
ρ
Capacity P
Inlet pressure p
u
VAS 1 on main valve
or orifice diameter d
Opening time t
L
Metric
Imperial
Nominal flow rate Q
(N)
Max. gas volume
in combustion chamber V
O
Erdgas H
914
BTU/scf
0,049 lb/ft3
3782000
BTU/h
40,0 "WC
3531 SCFH
13,2
Gallon
VAS 6 bis 9
0,70 inch
2 s