Читать книгу Automation of Water Resource Recovery Facilities - Water Environment Federation - Страница 136

Loop diagrams are an important part of I&C design. However, because they are specific to the actual devices used, they cannot be created until the system integrator has been selected and the user or design engineer has accepted all instruments, control panels, control systems, valves, and so on. Loop diagrams typically are prepared by the I&C contractor or system integrator, not the design engineer. In some instances, end users with available staff may choose to prepare these in-house. (For specific guidance on preparing loop diagrams, see ISA Standard S5.4 [Meier and Meier, 2011].)