FCU 500, FCU 505 · Edition 02.17
53
Valve proving system
7 .2 .5 Measurement time t
M
The sensitivity of the tightness control in the FCU can
be adjusted for each individual system by adapting the
measurement time t
M
. The longer the measurement
time t
M
, the greater the sensitivity of the tightness
control. The measurement time is set using param-
eters 56 and 57 to a value between 3 and 3600 s – see
page 110 (Measurement time V
The required measurement time t
M
is calculated from:
Inlet pressure p
u
[mbar]
Leakage rate Q
L
[l/h]
Test volume V
p1
+ V
p2
[l]
Calculation of the test volume – see page 54 (Test
volume Vp)
For one test volume V
p1
(between 2 gas solenoid
valves or for system tightness)
Adjustable using parameter 56
t
M
[s] =
(
2 × p
u
x V
p1
)
Q
L
For a large test volume V
p1
with reduced testing time
Adjustable using parameter 56
t
M
[s] =
(
0.9 × p
u
x V
p1
)
Q
L
For two test volumes for system tightness (V
p1
+ V
p2
)
Adjustable using parameter 57
t
M
[s] =
(
2 × p
u
x (V
p1
+ V
p2
)
)
Q
L
For two large test volumes (V
p1
+ V
p2
) with reduced
testing time
Adjustable using parameter 57
t
M
[s] =
(
0.9 × p
u
x (V
p1
+ V
p2
)
)
Q
L
Conversion into US units – see page 142 (Converting
units)
Leakage rate
The FCU tightness control makes it possible to check a
specific leakage rate Q
L
. Within the scope of the Euro-
pean Union, the maximum leakage rate Q
L
is 0.1% of
the maximum flow rate Q
max.
[m
3
/h].
Leakage rate Q
L
[l/h] =
Q
max.
[m
3
/h] x 1000 [l/h]
1000 x 1 [m
3
/h]
▼
