Doosan says its new DXB170H hydraulic breaker features nitrogen gas-assisted operation for improved efficiency. The 3,572-pound breaker delivers up to 600 blows per minute and is designed for use with excavators in the 18- to 28-metric-ton weight range. Rated in the 5,000 foot-pound impact energy class, the breaker requires a hydraulic flow rate between 26.5 and 39.5 gallons per minute. Tight tolerances in the manufacture of the pistons and cylinders eliminate leaks and jamming and guarantee full interchangeability of replacement parts, according to the company. Other features include a patented hydraulic dampening system said to prevent blank-fire damage, an energy recovery system said to increase strike power using energy generated by piston rebound, a patented main valve design said to reduce hydraulic pressure peaks, as well as a suspension system that extends boom life by absorbing harmful vibrations and stress waves.