Unistress Piston Ring Expander / UPRE

UPRE Unistress Piston Ring Expander


The Unistress Piston Ring Expander subject the ring to four forces as indicated and

therefore to a uniform moment throughout, except at the ends where it decreases rectilinearly towards zero.


• Ensures easy changing of piston rings without any risk for geometrical distortion of the ring,

leading to increased ring and liner life and reduced lube oil consumption.


• Patented technology creating uniform bending moment throughout the piston ring allowing for safe opening.


• Delivered adjusted and ready to use for all medium speed and slow speed engine bore sizes.