EN856 4SP Hose Assembly for Construction Machinery

 In the hydraulic systems of various heavy-duty construction machinery such as excavators, loaders, shield tunneling machines and mining hydraulic supports, the ‌EN856 4SP hydraulic hose assembly‌, with its high-strength structure of four layers of spirally wound steel wires, serves as the core fluid transmission component under working conditions with high load and high pulse. Combined with the full range of specification parameters, hydraulic hoses of corresponding sizes and pressures can be accurately matched for different operation scenarios, maximizing the service life of equipment while ensuring safety redundancy.

 High-Impact Circuits: Matching Small-Diameter High-Pressure Specifications

These scenarios are mainly concentrated in the pilot control circuits, hydraulic breaker impact oil circuits and small actuator oil supply circuits of construction machinery, where the hoses need to withstand instantaneous high-frequency high-pressure impacts. Specifications with small diameters and high pressure levels are preferred:

• 1/4" specification: Inner diameter 6.2~7.0mm, working pressure 45MPa, minimum bending radius 150mm, suitable for the control oil circuit between the pilot handle and the solenoid valve group of excavators. The compact bending radius can adapt to the narrow wiring space around the valve block.
• 3/8" specification: Inner diameter 9.5~10.5mm, working pressure 44.5MPa, minimum bending radius 178mm, suitable for the oil inlet circuit of hydraulic breakers. The rated pressure of 44.5MPa can fully cover the instantaneous impact peak during breaking operations and avoid early bulging failure of the hose.
• 1/2" specification: Inner diameter 12.5~13.5mm, working pressure 41.5MPa, minimum bending radius 230mm, suitable for the oil supply circuit of the rodless chamber of the boom cylinder of small excavators, maintaining stable pulse resistance during frequent lifting operations.

 Main Actuator Circuits: Matching Medium-Diameter Medium-Pressure Specifications

These scenarios cover the main action oil circuits of construction machinery, which are the main circuits for equipment operation, where the flow demand and pressure load are in a balanced range. They are suitable for specifications with medium diameters and medium pressure levels:

• 5/8" specification: Inner diameter 15.5~16.7mm, working pressure 35MPa, minimum bending radius 250mm, suitable for the main oil supply circuit of the bucket cylinder of loaders. The rated pressure of 35MPa can fully cover the peak load of shoveling operations.
• 3/4" specification: Inner diameter 18.6~19.8mm, working pressure 35MPa, minimum bending radius 300mm, suitable for the arm cylinder circuit of medium-sized excavators, taking into account large flow transmission capacity and load impact resistance.
• 1" specification: Inner diameter 25.0~26.4mm, working pressure 32MPa, minimum bending radius 340mm, suitable for the luffing cylinder circuit of large cranes, keeping the pipeline pressure loss within a reasonable range in long-distance large-flow oil supply scenarios.

 Large-Flow Transmission Circuits: Matching Large-Diameter Low-Pressure Specifications

These scenarios are mainly concentrated in the main pump oil outlet main circuit, main oil return circuit and heat dissipation system oil supply circuit of construction machinery. The core demand is large-flow low-resistance transmission, which is suitable for specifications with large diameters and low pressure levels:

• 1 1/4" specification: Inner diameter 31.4~33.0mm, working pressure 21MPa, minimum bending radius 460mm, suitable for the main oil supply circuit of the screw conveyor of large shield tunneling machines, meeting the demand of large-flow driving.
• 1 1/2" specification: Inner diameter 37.7~39.3mm, working pressure 18.5MPa, minimum bending radius 560mm, suitable for the main oil return pipeline of the hydraulic lifting system of mining dump trucks, greatly reducing the oil return resistance and improving the heat dissipation efficiency of the system.
• 2" specification: Inner diameter 50.4~52.0mm, working pressure 16.5MPa, minimum bending radius 660mm, suitable for the main oil suction pipeline of the hydraulic oil tank of large construction machinery, maintaining the anti-collapse capacity of the hose under low negative pressure conditions and ensuring the oil supply stability of the main pump.

The test pressure of the full range of ‌EN856 4SP hydraulic hose assemblies‌ reaches twice the working pressure, and the minimum burst pressure reaches 4 times the working pressure. All specifications can achieve a pulse life of more than 800,000 cycles, fully covering the operation requirements of construction machinery throughout its life cycle.