Description: Period of time during which an item performs its intended function, it includes all the time a machine is continuously running from start-up until it is shut down.; Name: ot
Description: passed time period after comissioning of a system, sub-system, component or piping; Name: Operating time 
Description: a specific design within the context of a type, which is generally characterized by its dimensions. A construction can comprise several design (variants), which generally vary in terms of mechanical details; Name: Construction form of the seal surface, connection, muff A2