F MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F04 POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
F04D NON-POSITIVE-DISPLACEMENT PUMPS
29/00 Details, component parts, or accessories
F04D29/02 Selection of particular materials
F04D29/026 especially adapted for liquid pumps