4SP Hose for Coal Mine Hydraulic Supports

4SP Hydraulic Hoses for Coal Mine Hydraulic Supports: The High-Pressure Fluid Lifeline of Fully Mechanized Mining Faces

In the extreme underground operating environment with high humidity, heavy dust and strong impact, coal mine hydraulic supports are the core equipment to ensure the safety of the fully mechanized mining face roof and realize efficient coal mining. The 4SP four-layer steel wire wound hoses that meet the EN856 standard are the key fluid transmission components supporting the stable operation of hydraulic supports. They are fully adapted to the special working conditions in underground coal mines and have become the most widely used medium and high-pressure hydraulic hose category in the current fully mechanized mining systems.

 Exclusive Product Structure of Coal Mine-Specific 4SP Hoses

Different from ordinary engineering machinery hoses, coal mine-specific 4SP hoses adopt a five-layer composite reinforced structure, which is designed layer by layer to adapt to the harsh underground environment: the innermost layer is a nitrile synthetic rubber layer with excellent oil and water resistance, which can stably be compatible with media commonly used in hydraulic support systems such as emulsions and water-based hydraulic oil, preventing media penetration and corrosion of the internal skeleton. Outside the inner rubber layer, four layers of high-tensile steel wires are laid in sequence, forming the core pressure-bearing skeleton through staggered spiral winding, enabling the full range of products to cover a working pressure range from 16.5MPa to 44.5MPa, with a pressure resistance far exceeding that of ordinary two-layer steel wire braided hoses. The outermost layer is a modified flame-retardant and anti-static synthetic rubber layer. In addition to conventional wear resistance and aging resistance, it also fully complies with the MT/T 98 safety standard for the coal industry, eliminating safety hazards such as static sparks and open flame spread in underground flammable and explosive environments.

Precise Selection and Adaptation for Different Circuits

In actual selection and matching, 4SP hoses of different specifications are precisely corresponding to different functional circuits of hydraulic supports: the 3/8 inch small-diameter specification is suitable for the pilot control oil circuit of the supports, and its compact minimum bending radius of 180mm can meet the wiring requirements in the narrow space around the valve group. The medium-diameter specifications from 1/2 inch to 1 inch are adapted to the main oil supply circuits of support columns and pushing oil cylinders, and their rated pressure of 35MPa to 41.5MPa can fully cover the instantaneous load peaks during support moving and column lifting operations. The large-diameter specifications from 1 1/4 inch to 2 inches are used for the main oil inlet and return manifolds of the supports, reducing pipeline resistance while ensuring high-flow oil supply efficiency. The full range of products has a pulse life of more than 800,000 cycles, which fully adapts to the long-term high-frequency operation rhythm of underground hydraulic supports, and greatly reduces the risk of working face shutdown caused by sudden hose failure.

From the 10-million-ton fully mechanized mining faces to small and medium-sized underground mining roadways, 4SP hoses have become irreplaceable fluid transmission components in coal mine hydraulic systems with their high reliability, building the last pressure-bearing defense line for underground safety production.