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: relationship between the total head of the pump and the rate of flow at given operating conditions /rated conditions of speed and liquid; Name: Pump efficiency curve