The EPYY11112021 Main Boom Angle Cylinder (also known as a crane luffing cylinder) is the primary structural actuator responsible for raising and lowering the main telescopic or lattice boom. Tasked with supporting hundreds of tons of cantilevered weight, this truck crane hydraulic ram must provide absolute rigid control during the most critical phases of a lift.

Forged from premium ST52.3 steel, this model serves as a high-performance aftermarket replacement for leading mobile crane brands such as Liebherr, Terex, Tadano, and Sany. It is specifically optimized for high-cycle luffing where precision angle maintenance and resistance to structural sway are paramount for job site certification.

The EPYY11112021 functions as a massive double-acting hydraulic hoist. In mobile crane applications, it is the fundamental pivot point for the boom assembly. By converting 31.5MPa of system pressure into linear extension, it provides the torque necessary to lift the boom from its retracted travel position to its maximum vertical angle.

Hydraulic Performance: Utilizing a colossal Φ280mm internal bore, the cylinder generates enormous breakaway force. The thick Φ250mm rod is specifically engineered for “anti-buckling” strength, ensuring the boom stays rigid even at horizontal angles where gravitational leverage is at its peak.

Blueprint Anatomy: As detailed in the CAD schematic, the cylinder features a 4218mm installation profile. A key design feature is the integrated manifold porting for high-flow counterbalance valves, preventing uncontrolled boom drops in the event of hose failure. The rod end and barrel base are equipped with oversized spherical plain bearings to absorb the structural flex inherent in 100-ton lifting tasks.

1155kg Stabilizing Mass

The massive 1155kg build provides the material density required to sustain 31.5MPa pressures over a massive 3.5m stroke without structural fatigue.

39MPa Surge Immunity

Cranes face violent wind-load spikes and sudden load shifts. Our 39MPa withstand rating ensures the steel barrel remains immune to swelling.

Zero-Drift NOK Sealing

Utilizing imported Japanese NOK seals to eliminate internal bypass. This ensures the main boom maintains a constant angle for hours without creeping.

Anti-Buckling Φ250mm Rod

The massive rod diameter is induction-hardened to provide unparalleled columnar strength, critical when the boom is fully extended under maximum weight.

As a dedicated Heavy-Duty Crane Cylinder Manufacturer, we recognize that boom actuator failure is not an option. We utilize uncompromised metallurgy to ensure the EPYY11112021 outlasts the chassis it serves.

The 1155kg assembly is milled from ST52.3 (E355) high-yield strength seamless steel. The internal bore is CNC skived and roller-burnished to a mirror Ra 0.2µm finish, dramatically extending seal life even in dusty construction environments.

• Quenched Φ250mm Rod: Forged from high-tensile 45# carbon steel, induction-quenched for impact resistance, and coated in 50µm of hard chrome.
• Robotic Joint Welding: Port blocks and trunnions are fused using multi-pass robotic SAW welding, validated by ultrasonic NDT for zero porosity.
• 100% Quality Assurance: Every 1155kg unit undergoes a mandatory 39MPa hydrostatic hold test before dispatch to verify weld and seal integrity.

The EPYY11112021 providing critical, 31.5MPa boom elevation power for large-scale logistics.