Badger Meter SRD/SRI Valve Positioners - Manual (Page 54)

Partial Stroke Test
The Partial Stroke Test (PST) is used for testing of the ESD capabilities of
safety shutdown valves . Since the safety-related valves are always fully
open and do not move within normal operation, it is very important to
identify if a valve would close, in case the safety system shuts down the
valves .
For this purpose the PST is used . It lets you manually or automatically
stroke the valve by applying a configurable Setpoint Change and a Max.
Wait Time for Position Change .
Once the PST is activated and a Setpoint Change is configured at,
for example, 10% and the Max. Wait Time for Position Change to, for
example, 30 seconds, the positioner will move the valve at 10% from
the fully open 100% to approximately 90% valve position .
If the valve does not move instantly, the positioner will wait for 30 seconds to move the valve . After the test in finished, the
positioner will generate a Testing Status . The Testing Status can be retrieved by pressing Update .
The test will result in displaying a Partial Stroke Test Status showing the different states such as Not Done, Running, Restricted,
OK or Error . If the PST has failed the display will show Maintenance, to identify the operator of a failure .
Activation of Partial Stroke Test
The Partial Stroke Test can only be activated if the setpoint and the valve position is greater than 99% . If the setpoint and the
valve position is below 99% the Testing Status: Restricted will be shown .
Automatic
The Partial Stroke Test can be set to Automatic, by checking the box . In this case the Time Interval has to be set to the value,
after what time the test shall be repeated . The table shows some rough time-intervals . For example, the Time Interval is
configured with 4380 hours . In this case every 4380 hours a Partial Stroke Test is executed . If the setpoint and the valve
position is below 99% the Testing Status: Restricted will be shown .
Years Months Days Hours
0 .5 6 182 .5 4380
1 12 365 8760
2 24 730 17520
3 36 1095 26280
4 48 1460 35040
5 60 1825 43800
10 120 3650 87600
Manual
Press the Start button to execute the Partial Stroke Test . The Test will then perform a Setpoint Change with a Max. Wait Time for
Position Change as configured .
Time Interval
The Time Interval has to be set to the value, after what time the Partial Stroke Test shall be repeated, when the Test is set to
Automatic . The table shows some rough time-intervals . For example, the Time Interval is configured with 4380 hours . In this
case, every 4380 hours a Partial Stroke Test is executed .
The interval can be configured between 0 .1 to x hours . The value is preset to 8760 hours .
Setpoint Change
The Setpoint Change is the percentage of the valve movement from the fully open valve position . If this value is set, for
example, to 10%, the Setpoint Change will move the valve from fully open at 100% to 90% valve position .
Configuration / Parameter
Page 54 August 2014 POS-UM-00011-EN-02