21.120.20 - Couplings

IEC 60744:2018 provides requirements and recommendations for the design, construction and test of safety logic assemblies used in safety systems to perform category A safety functions (in accordance with IEC 61226). Safety logic assemblies include logic such as the hardwired logic assembly interfacing computer-based systems to switchgear, actuators or contactors to provide trip or engineered safety feature actuations. Safety logic assemblies are significant parts of a safety system and may inclu...view more

Includes principles of design, construction and testing of safety logic assemblies used in protection systems. Gives recommendations for the implementation of the general principles of nuclear reactor instrumentation in IEC 60231A. It includes provisions for acceptance and in-service testing reliability criteria and protection from external influences. Safety logic functions performed within the safety logic assemblies are not included. IEC 60744 is no longer up-to-date and will not be revised b...view more

This International Standard specifies the requirements for couplings for the transmission of power between the rotating shafts of two machines in special-purpose applications in the petroleum, petrochemical and natural gas industries. Such applications are typically in large and/or high speed machines, in services that can be required to operate continuously for extended periods, are often unspared and are critical to the continued operation of the installation. By agreement, it can be used for ...view more

This International Standard specifies the requirements  for couplings for the transmission of power between  the rotating shafts of two machines for general  purpose applications in the petroleum, petrochemical  and natural gas industries. Such applications typically  require couplings to transmit power at speeds not  exceeding 4 000 r/min, between machines in which  the first lateral critical speed is above the running  speed range (stiff-shaft machines). It may, by  agreement, be used for appl...view more

ISO 14691:2008 specifies the requirements for couplings for the transmission of power between the rotating shafts of two machines for general-purpose applications in the petroleum, petrochemical and natural gas industries. Such applications typically require couplings to transmit power at speeds not exceeding 4 000 r/min, between machines in which the first lateral critical speed is above the running speed range (stiff-shaft machines). ISO 14691:2008 can, by agreement, be used for applications o...view more

Gives specifications in order to facilitate communication and understanding. Does not apply to rigid flange or sleeve couplings; torsionally stiff couplings for alignment purposes, all types of slip couplings. Does not give dimensional requirements for either shafts or couplings.