Control Valve Partial Stroke Testing (PST) for Safety Valves

Practical Procedure · Safety Systems Control Valve Partial Stroke Testing (PST) for Safety Valves Applies to: Emergency shutdown (ESD) valves and safety instrumented function (SIF) final elements  |  Equipment needed: PST-capable positioner/logic solver, position feedback monitoring, coordination with process/operations Full Stroke vs. Partial Stroke — Why PST Exists Tap a tab to see the difference between a full functional test and a partial stroke test, and why PST lets you test without shutting down. Full Stroke Test Partial Stroke Test (PST) ESD Valve — Process Running 0% → 100% → 0% process fully interrupted during test ESD Valve — Process Running ...
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About

 I'm Aamir Malik, and I've spent close to 25 years working hands-on in industrial instrumentation — most of it in cement manufacturing, including time on international projects. I currently lead the Instrumentation & Control team at a cement plant, where I deal daily with the same DP transmitters, PLCs, control valves, and flow meters I write about here.

This blog started as a way to document what actually happens in the field — not the textbook version, but the version where an impulse line is blocked, a plate's been installed backward, or a PLC card is throwing a transient fault nobody can explain. Over the years it's grown into a reference for fellow instrumentation professionals, technicians, and engineers who want practical, tested troubleshooting knowledge rather than generic theory.

Everything here is written from direct plant experience. If it's on this blog, it's because I've either dealt with it myself or worked through it with my team.

Topics you'll find here include flow, level, pressure, and temperature measurement; control valves and actuators; PLC and DCS troubleshooting; gas analyzers; and general fault-tracing procedures for cement and process plants.

Feel free to browse, and if something here helps you solve a problem on your own plant, that's exactly why I write it.

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