ISO 19880-1-2020 pdf download

ISO 19880-1-2020 pdf download.Gaseous hydrogen一Fuelling stations一 Part 1: General requirements. 3.71 safety function function to be implemented by a safety-instrumented system (172). which is intended to achieve or maintain a safe state for the process, with respect to a specific hazardous situation Note 1 to entry: Other technologies or risk reduction measures have a safety function not achieved through a safety-instrumented system, however validation of these measures Is equally important. 3.72 safety-instrumented system S’S instrumented system used to implement one or more safety-instrumented functions Note ito entry: A safety-instrumented system is composed of any combination of sensors, logic solvers, and final elements. Note 2 to entry: A separate safety-instrumented system (SIS), typically with a greater reliability than the more basic process control system (BPCS) (j4), can be required, according to the manufacturer’s risk assessment (3.Ith). to respond solely to safety critical alarms. Further information is provided by IEC 61508 and IEC 61511. 3.73 safety Integrity level SIL discrete level (one out of a possible four), corresponding to a range of safety integrity values, where safety integrity level 4 has the highest level of safety integrity and safety integrity level 1 has the lowest Note Ito entry: The target failure measures (see IEC 61508-4) for the four safety integrity levels are specified in IEC 61508-1:2010, Tables 2 and 3. Note 2 to entry: Safety integrity levels are used for specifying the safety integrity requirements of the safety functions (171) to be allocated to the E/E/PE safety-related systems (174). Note 3 to entry: A safety integrity level (SIL) is not a property of a system, subsystem, element or component. The correct interpretation of the phrase SlL n safety-related system” (where n is 1, 2, 3 or 4) is that the system is potentially capable of supporting safety functions with a safety integrity level upton. Note 4 to entry: See Z. [SOURCE: IEC 61508-4:2010, 3.5.8, modified — Note 4 to entry has been added.J 3.74 safety-related system designated system that both implements the required safety functions (121) necessary to achieve or maintain a safe state for the EUC and is intended to achieve, on its own or with other E/E/PE safety- related systems, other technology safety-related systems or external risk reduction facilities, the necessary safety integrity for the required safety functions Note 1 to entry: The term refers to those systems, designated as safety-related systems, that are intended to achieve, together with the...