Instruction Manual

Instruction Manual
D103557X012
Configuration
January 2015
30
3. Run a partial stroke test.
4. Select the Press/Time radio button on the partial stroke graph (refer to the example in figure 3‐3, bottom plot). If
the actuator pressure starts high and moves low, find the minimum actuator pressure (Pmin). If the actuator
pressure starts low and moves high, find the maximum actuator pressure (Pmax). Doubleacting actuators will
display differential pressure. Use table 3‐8 to estimate the partial stroke pressure limit.
Table 3‐8. Estimates for Partial Stroke Pressure Limits
Actuator Style Relay Type Zero Power Condition PST Starting Point Partial Stroke Pressure Limit
(1)
Spring and
Diaphragm
A or C
Closed
Open Pmin - 0.25 * (Bench Set High - Bench Set Low)
Closed Pmax + 0.25 * (Bench Set High - Bench Set Low)
Open
Open Pmax + 0.25 * (Bench Set High - Bench Set Low)
Closed Pmin - 0.25 * (Bench Set High - Bench Set Low)
B
Closed
Open Pmax + 0.25 * (Bench Set High - Bench Set Low)
Closed Pmin - 0.25 * (Bench Set High - Bench Set Low)
Open
Open Pmin - 0.25 * (Bench Set High - Bench Set Low)
Closed Pmax + 0.25 * (Bench Set High - Bench Set Low)
Single Acting Piston
A or C
Closed
Open 0.5 * Pmin
Closed Pmax + 0.5 * (Psupply - Pmax)
Open
Open Pmax + 0.5 * (Psupply - Pmax)
Closed 0.5 * Pmin
B
Closed
Open Pmax + 0.5 * (Psupply - Pmax)
Closed 0.5 * Pmin
Open
Open 0.5 * Pmin
Closed Pmax + 0.5 * (Psupply - Pmax)
Double Acting Piston A
Closed
Open Pmin - 0.5 * (Psupply + Pmin)
Closed Pmax + 0.5 * (Psupply - Pmax)
Open
Open Pmax + 0.5 * (Psupply - Pmax)
Closed Pmin - 0.5 * (Psupply + Pmin)
5. Enable the parameters that were previously disabled:
D Travel Deviation Alert - set to 1.5x the maximum travel deviation between travel set point and travel.
D End Point Pressure Control - enable
D Partial Stroke Pressure Limit - calculate the value using table 3‐8.
PST Enable—Yes or No. This enables or disables the Partial Stroke Test.
PST Start Point—Valve Open or Valve Closed. This defines the travel stop that the valve needs to be at before a partial
stroke test can be initiated. This also defines the travel stop for end point pressure control. Setting this value to Not
Configured will disable partial stroke tests and end point pressure control.
PST Variables—Follow the prompts on the Field Communicator display to enter or view information for following PST
Variables:
D Max Travel Movement— This is the percentage of total span that the valve moves away from its normal operating
state towards its tripped state during the test. The default value is 10%.
D Test Speed—This is the rate at which the valve will move during the test. The default value is 0.25%/second.
D Pause Time—This is the pause time between the up and down strokes of the test. The default value is 5 seconds.