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單項選擇題

（）can be used to prevent hydraulic system overloaded or keep the pressure of oil outlet from pump constant.

A.Overflow valve
B.Reducing valve
C.Balancing valve
D.Reducing valve or balancing valve

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單項選擇題

The symbol (GB786√1-93) at right side represents （）

A.overflow valve
B.reducing valve
C.relief valve
D.sequence valve

單項選擇題

The symbol (GB786√1-93) at right side represents （）

A.overflow valve
B.reducing valve
C.relief valve
D.sequence valve