Most hydraulic hoses are classified according to pressure, diameter, number of steel wires and joint type. The oil inlet pipe and oil return pipe are mostly low-pressure pipes, generally below 1 layer, 16Mpa! The oil outlet pipe is a high-pressure oil pipe, which is selected according to the system pressure.
Hard pipes are made of metal materials, generally Q235 and stainless steel (1Cr 18Ni9Ti). There is also an oil suction pipe from the oil tank to the pump, usually a resin hose wrapped with steel wire!