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: internal volume of a compartment, including the volume of nozzles to the first connection (flange, coupling, screwed connection, weld seam) but excluding the volume of internal structures (e. g. baffles, agitators); Name: Filling volume of the equipment