by changing the effective cross-section of the working surface of the piston

Full Title

Control of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for in, or of interest apart from, groups > by changing the effective cross-section of the working surface of the piston

Classification Context

Section:

MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING

Class:

POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS

Subclass:

POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS