FCU 500, FCU 505 · Edition 02.17 44
Valve proving system
t
L
= P59
t
M
= P56
+
–
t
L
= P59
t
M
= P56
p
Z
>
p
u
2
+
–
V2
OK
p
Z
>
p
u
2
V1
OK
V1
V2
OK
V1
V1
V1
OK
V2
V2
V2
V1
V2
p
Z
>
p
u
2
+
–
p
Z
>
p
u
2
+
–
t
L
= P59
t
M
= P56
V1
V1
t
L
= P59
t
M
= P56
V2
V2
p
Z
>
p
u
2
+
–
V
p1
OK
p
Z
>
p
u
2
+
–
t
L
= P59
t
M
= P57
V1
V2V3
V1
V
p2
Program A Program B
Program A Program B
Test of valve 1
V
p1
Test of valve 2
V
p1
Test of valve V3
and
burner-side
valves
V
p1
+ V
p2
Wait for 1 s
END
START
Program B
Valve V2 opens for the opening time t
L
set in param-
eter 59. Valve V2 closes again. During the measure-
ment time t
M
set in parameter 56, the tightness control
checks the pressure p
Z
between the valves V1 and V2.
If the pressure p
Z
< p
u
/2, valve V1 is leaking.
If the pressure p
Z
> p
u
/2, valve V1 is tight.
Valve V1 opens for the opening time t
L
set in param-
eter 59. V1 closes again. During the measurement
time t
M
, the tightness control checks the pressure p
Z
between the valves.
If pressure p
Z
> p
u
/2, valve V2 is tight.
If pressure p
Z
< p
u
/2, valve V2 is leaking.
The test volume V
p1
has been successfully checked for
tightness.
For checking the second test volume, see page 45
(Checking the first and second test volumes (V
p1
+ V
p2
)).