Single hydraulic prop is composed of cylinder block, movable column, valve and other parts. The three-way valve is the heart of external injection hydraulic prop, which is composed of one-way valve, unloading valve and safety valve.
The one-way valve is used to supply liquid for single hydraulic prop, and unloading valve is used for unloading and returning hydraulic prop. The safety valve ensures the constant resistance of hydraulic prop.
Acrow prop can be used for supporting roof of high-grade common mining and blasting working face as well as supporting end of fully mechanized working face with metal hinged top beam. It can also be used as point column or other temporary support. It can be applied to the mining face of inclined coal seam with coal seam dip angle less than 25-35 degrees.
The conditions of roof and floor for acrow prop are as follows: the backward roof does not affect the recovery of prop, the floor should not be too soft, the depth of pillar pressing into the floor does not deteriorate the integrity of the floor, otherwise, the base should be increased.
