In a standard three-stage hydraulic breaker, the Back Head serves as the top pressure-retaining cap and energy buffer of the power cell. It houses the compressed Nitrogen (N₂) gas cushion chamber, holds the gas charging valve, and absorbs clamping loads from the main through-bolts. Back Head failures—such as rapid nitrogen gas loss, fatigue cracking around bolt pockets, and mating joint leaks—are frequently caused by contaminated fluid, asymmetric bolt torque, or blank firing. This technical guide outlines the structural role of the Back Head in three-stage breakers, common failure root causes, step-by-step field inspection protocols, dye penetrant crack testing, and multi-stage cross-pattern bolt torquing standards. SLYM precision 20CrMo forged Back Heads eliminate casting porosity, providing long-term gas tightness and fatigue resistance for heavy mining applications.
