TC · Edition 08.17
22
Function
3 .1 .3 Test procedure for TC 1, TC 2, TC 3
Depending on the pressure between the valves p
z
, the
tightness control TC carries out a check using test pro-
cedure
A
or
B
:
If pressure p
z
> p
u
/2, program A starts.
If pressure p
z
< p
u
/2, program B starts, see page 23
Test procedure A
Valve V1 opens for the opening time t
L
= 3 s and closes
again. During the measurement time t
M
, the tightness
control checks the pressure p
z
between the valves.
If pressure p
z
is less than half the inlet pressure p
u
/2,
valve V2 is leaking.
If pressure p
z
is greater than half the inlet pressure p
u
/2,
valve V2 is tight. Valve V2 is opened for the set opening
time t
L
. V2 closes again.
During the measurement time t
M
, the tightness control
checks the pressure p
z
between the valves.
If pressure p
z
is greater than half the inlet pressure p
u
/2,
valve V1 is leaking.
If pressure p
z
is less than half the inlet pressure p
u
/2,
valve V1 is tight.
The tightness test can only be performed if the pres-
sure downstream of V2 is around atmospheric pressure.
t
L
= 3 s
t
M
–
–
+
+
+
–
t
M
p
z
>
p
u
2
V1
V1
V1
p
z
>
p
u
2
V2
OK
V2
V1
OK
V2
V2
t
L
= 3 s
t
L
= 3 s
t
M
+
–
t
M
p
z
>
p
u
2
+
–
V2
V2
V2
p
z
>
p
u
2
V1
OK
V1
V2
OK
V1
V1
t
L
= 3 s
p
u
p
z
p
z
>
p
u
2
TEST
V1
V2
Test procedure
A
Test procedure
B
START