We are pleased to announce that Chris-Marine is now responsible for the manufacturing, sales and marketing of the Unistress Piston Ring Expanders.

The Unistress piston ring expanders are available in 4 different types covering piston ring diameters from 100 mm up to 980 mm. The product is extremely compatible with the rest of Chris-Marine’s product portfolio, and we are therefore very satisfied that we are now able to offer this quality product to our customers.

Unistress was founded in 1948 by Anders Østergaard, a former MAN B&W employee, and the unique expanding principle with equal pressure on all sides of the piston ring was patented in 1949.

The UPRE features a number of advantages:

  • Ensures easy changing of piston rings
  • Patented technology creating uniform moment throughout the piston ring allowing for safe opening.
  • Each UPRE is provided with a stop, limiting the deformation of the ring to the minimum required to slip it over the piston diameter
  • Delivered adjusted and ready to use for any type of piston ring and diameter upward of 100 mm.