Flowserve Logix MD+ ValveSight - Manual (Page 184)

ValveSight™ Diagnostics DTM Manual for Logix MD+ Positioner with HART®
FCD- LGENSF0014-00
© Flowserve Corporation
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Partial Stroke Test
The Partial Stroke Test page allow you to adjust settings and run a step test. The Partial
Stroke Test (PST) is a powerful tool for "in-service testing" of valves that are normally fixed
at one end of travel. Normally this is used with safety valves that are fully open and can be
stroked partially closed without affecting the process. The PST steps the valve with a
known step size, and monitors the response time. Increasing stroking times can indicate
that the valve may need service.
CAUTION: During a test the valve will not respond to control signals and movement of the
valve stem will occur.