Partial Stroke Testing is a practice in many refineries that does not cause significant interference or failure of the valve test to the manufacturing process. The shut-off valve, which is normally activated by a solenoid valve, is in a safety circuit and is the operator's first choice for shutting down a process line in an emergency. As part of its extensive line of control valves, positioners and accessories, Samson Controls in Germany offers a range of Electro pneumatic positioners that enable stroke testing to be performed without interfering with the process line. For example, the 3730-3 positioner includes an emergency shutdown feature that allows stroke testing without closing the process line. It can be mounted on a valve, in addition to a solenoid valve, or in place of it and within the working ratio of the valve, allowing the valve to move precisely to the set point. Some stroke tests have been fully integrated into the positioner to monitor valve sticking, such as corrosion. The test schedule can be flexibly set as required, extended if necessary to suit specific application requirements, and test verification can be performed using the appropriate instrumentation. This article keyword search: valve supply information