Description: the head of a pump at the point of best efficiency; Name: head at optimum efficiency
Description: Total head developed by the pump at a rate of flow corresponding to the best efficiency; Name: Optimum head
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 A1