11. Return the column requires two people to cooperate, one person back to the column, one person to observe the top plate. When returning to the column, operators must work in a safe and secure location. Clean up the retreat, lay the pillars of the body, and inform other people working nearby.
12. When the top plate is pressed and encounters other dangers, stop the column and wait until it is processed.
13. When the over-capacity of the large area and the pressure of the roof are too large, the column may not be manually returned, operators should return the column by winch or other safe means.
14. When the single hydraulic prop is unloaded, it must be unloaded remotely using an unloading handle or special tool. When unloading, it must be gradually unloaded from small to large. After the roof is stable, the pillars can be quickly unloaded after they are separated from the top beam.
15. If the "three-way valve" is damaged, it should be replaced in time. The replaced three-use valve should not be randomly thrown and managed.
16. The pillars should be lightly loaded and unloaded during transportation and are not allowed to wrestle at will.
17. For short-term unused pillars, you should drained the liquid in the column, and blocked the three-way valve inlet hole to prevent duct entering.
18. It is strictly forbidden to use props instead of other lifting tools to lift objects.
19. The working face using the single hydraulic props must be observed through the roof pressure as the basis for the preparation of the “procedures” and pillar selection.
