Product Description To control the hydraulic support rack of the coal mine and block the high-pressure liquid in the lower cavity (piston cavity), so that the rack plays an auxiliary role; When the upper cavity of the column introduces liquid while giving liquid to control the recognition, the lower cavity of the column is unlocked so that the column falls. And by adjusting the opening pressure of the safety valve installed on the hydraulically controlled one-way valve, the working resistance of the hydraulic bracket is in the nominal value. Specifications Rated pressure: 50MPa Rated flow rate: 200L/min, 400L/min Interface throughput: as per user request Material: medium carbon/stainless steel/1 Cr18Ni9