This is a complete set of relief valves. The role of the relief valve is to control the amount of oil during the normal use of the bending machine, including its pressure, to control it. If this valve is stuck and the spool does not work properly in this valve, what happens to the bender? It cannot be raised, it cannot be lowered, and it cannot be pressurized, that is, the oil pump motor is rotating forward, but the slider of the bending machine has no movement.
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