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Partial stroke testing (or PST) is a technique used in a control system to allow the user to test a percentage of the possible failure modes of a shut down valve without the need to physically close the valve. PST is used to assist in determining that the safety function will operate on demand. PST is most often used on high integrity Emergency Shutdown Valves (ESDVs) in applications where closing the valve will have a high cost burden yet proving the integrity of the valve is essential to maintaining a safe facility. In addition to ESDVs PST is also used on High Integrity Pressure Protection Systems or HIPPS. Partial Stroke Testing is not a replacement for the need to fully stroke valves as proof testing is still a mandatory requirement. ==Standards== Partial stroke testing (or PST) is an accepted petroleum industry standard technique and is also quantified in detail by regulatory bodies such as the International Electrotechnical Commission (or IEC) and the Instrument Society of America (or ISA). The following are the standards appropriate to these hotbodies. : *IEC61508 – Functional safety of electrical/electronic/programmable electronic safety-related systems : *IEC61511 – Functional safety – Safety instrumented systems for the process industry sector : *ANSI/ISA-84.00.01 – Functional Safety: Safety instrumented systems for the process industry sector These standards define the requirements for safety related systems and describe how to quantify the performance of PST systems 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Partial stroke testing」の詳細全文を読む スポンサード リンク
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