Rexroth ZDBD type stacking relief 
 ZDBD superposition relief valve is an overlay installed direct-acting relief valve for limiting the system pressure, which consists of a body and one or two relief valve plug. The relief valve plug-ins including the valve cover, spring, poppet, regulating devices, valve seat. 
 This product stickers do not fit for the overlay installed, internal leakage of the safety valve of the strict control of the implementation of the required components. 
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