The Reason For The Single Hydraulic Props Expansion Cylinder

Date:2018-10-09     Label：

Single Hydraulic Prop

Acrow Prop

Suspension Hydraulic Prop

The safety valve in the three-way valve is a key component that keeps the strut in a constant-resistance operating characteristic. When the working surface is affected by the mining, when the top plate is pressed, its constant resistance is achieved by the set opening and closing pressure. The results of the sampling test indicate that the safety valve is ineffective, the safety valve is not released after the strut reaches its working resistance. And the hydraulic energy is determined by the external load. When the top plate sinks, the external load is directly related to the fallen rock layer, and the pressure reflected to the piston cavity of the pillar is high.

Therefore, when the strength of the top of the working face is obvious, the pressure in the lower chamber of the pillar rises. When the safety valve is set to exceed the pressure, the overflow cannot be opened and the safety valve does not work. After the stress caused by it exceeds the allowable stress of the cylinder, deformation damage of the strut cylinder and even other components is caused.

It should be noted that the failure of the safety valve is not completely caused by its own cause. It is contaminated by a mixture of metal particles, coal dust, oxides and scales, oil degradants, etc., resulting in blockage. 

In summary, in the condition in which the expansion cylinder can be formed, the failure of the safety valve in the three-way valve is a major factor capable of forming the expansion cylinder. Of course, the failure of the unloading valve of the emulsion pumping station due to poor management of the inspection or the piston Y-shaped seal has quality defects is also an objective hidden danger.