what is the obturator ring
For other uses, see Obturator. Obturator rings are a specific type of piston ring used in World War I aero engines to compensate for warping of the cylinders.he rotary aircraft engines of World War I (engines with the crankshaft fixed to the airframe and rotating cylinders) were notoriously difficult to keep cool when operating. Thus, their very thin walled steel cylinders would become distorted to an unacceptable level.