Program Sequence - Honeywell Krom Schroder BCU 580 Technical Information

Valve proving system
+
Program A
V1
t L = P59
V1
V1
t M = P56
–
p u
p Z >
2
+
V2
V2
OK
V2
t L = P59
V2
t M = P56
+
p u
p Z >
2
–
V1 OK V1
BCU 580 · Edition 11.15l
START
–
p u
p Z >
2
Program B
t L = P59
V2
PZ
p /2
u
p
z
t M = P56
+
p Z >
V1
t L = P59
t M = P56
–
p Z >
V2

5 .1 .2 Program sequence

The tightness test starts by checking the external pres-
sure switch. If pressure p
If pressure p
(Program B).
V2
Program A
Valve V1 opens for the opening time t
eter 59. V1 closes again. During the measurement
time t , the tightness control checks the pressure p
M
V2
between the valves.
If pressure p
valve V2 is leaking.
p u
If pressure p
2
– pressure p
u
the set opening time t
V1 OK
During the measurement time t
V1
checks the pressure p
If pressure p
pressure p
u
V1
If pressure p
valve V1 is tight.
The tightness test can only be performed if pressure p
downstream of V2 is around atmospheric pressure and
p u
2
the volume downstream of V2 is at least 5 × higher than
+
the volume between the valves.
V2 OK
▼
> p /2, program A starts.
Z u
< p /2, program B starts, see page 32
Z u
is less than half the inlet pressure p
Z
is greater than half the inlet
Z
/2, valve V2 is tight. Valve V2 is opened for
. V2 closes again.
L
, the tightness control
M
between the valves.
Z
is greater than half the inlet
Z
/2, valve V1 is leaking.
is less than half the inlet pressure p
Z
set in param-
L
Z
/2,
u
/2,
u
d
31