Instruction Manual

DVC6000 SIS
September 2013
4-22
Manual SIS / Partial Stroke Parameter
Configuration
Note
In order to manually set the partial
stroke pressure limit with the correct
value, you must be able to run a valve
signature test using ValveLink
software (see figure 4-9). It is then
possible to set the partial stroke
pressure limit with the Field
Communicator, using the information
generated by the valve signature test.
Thresholds for detecting a stuck valve are
automatically configured when Setup Wizard or Partial
Stroke Calibration routines are run. However
thresholds can also be configured manually. To
manually configure thresholds, disable the travel
deviation alert by setting Travel Dev Alert Pt to 125%
(1-2-3-4-4-2). Also disable end point pressure control
(1-2-2-2-2-1) and disable the partial stroke pressure
limit (1-2-7-2) by setting the values shown in table 4-9.
Run the partial stroke test using the Field
Communicator. Once the test is completed, download
the partial stroke test results using ValveLink software.
On the partial stroke graph page, select the
Tvl(%)/Time radio button to plot travel set point and
travel time series traces. The Travel Deviation Alert
Point should be set at least 1.5 times the maximum
deviation obtained from the time series plot. Maximum
Travel Movement should be set at least 5% above the
Travel Deviation Alert Point.
Table 4-9. Values for Disabling Partial Stroke Pressure Limit
Actuator
Type
Relay Type
Zero
Power
Condition
Partial
Stroke
Start Point
Partial
Stroke
Pressure
Limit
(Disabled)
Single-
Acting
A or C
Closed
Open 0.0
Closed Psupply
Open
Open Psupply
Closed 0.0
B
Closed
Open Psupply
Closed 0.0
Open
Open 0.0
Closed Psupply
Double-
Acting
A
Closed
Open −Psupply
Closed Psupply
Open
Open Psupply
Closed −Psupply
On the partial stroke graph page, select the
Press/Time radio button to plot the pressure trace. If
the actuator pressure starts high and moves low, find
the minimum actuator pressure. If the actuator
pressure starts low and moves high, find the maximum
actuator pressure. Use table 4-10 to estimate the
partial stroke pressure limit.
In the example shown in the middle graph of figure
4-9, the maximum travel deviation between travel set
point and travel is approximately 4%. Travel Deviation
Alert Point should be set to 1.5 x 4% = 6%. Max
Travel Movement should be set at 6% + 5% = 11%.
In the bottom graph of figure 4-9, with a single-acting
piston actuator, fail closed, Relay A, and supply
pressure at 52 psig (read from instrument gauge),
Partial Stroke Pressure Limit is the minimum actuator
pressure attained during the test, i.e., 24 psig. Set the
Partial Stroke Pressure Limit to 0.5 * Pmin = 12 psig.
The default value is 0.
For double-acting valves, the differential pressure is
used.
 View/Edit Auto Test Interval
An interval of time (in days) between partial stroke
tests that are automatically run by the digital valve
controller, subject to the device being powered up. A
value of 0 disables this feature.
 Device Power Up
Defines the power up behavior of the DVC6000 SIS.
Auto Reset allows the valve to track the command
signal when power is applied to the device. Manual
Reset will lock the device in its safety position until the
digital valve controller is reset.
If Manual Reset is selected, its state can be
determined from the status monitor by monitoring the
Locked In Safety Position alert.
When Auxiliary Terminal Action is set to SIS Local
Control Panel (LP100), Device Power Up is set to
Manual Reset and cannot be changed to Auto Reset.
The reset signal depends on how the aux terminals
are configured. If configured for SIS Local Control
Panel, the digital valve controller can be reset by
pressing the button next to the green light on the
LCP100. If configured as Push Button Partial Stroke,
the digital valve controller can be reset by shorting the
aux terminals for more than 3 seconds but less than
10 seconds. The device cannot be reset from the aux
terminals if they are configured otherwise.
 Action on Failed Test
Displays the action taken by the instrument if a
communication timeout occurs. Values are Ramp
Back or Step Back.
4