AOLONG TRAILER CONTROL VALVE WITH SILENCER Material: Aluminum Alloy, Zinc Alloy, Nylon Machining: ... High quality foot brake valve,hand brake valve,relay valve,protection valve,air dryer,levelling valve and so on2. Strict quality control at ISO 9001: ... CNC machining centerInspection : 100% leakage test and other test.TRAILER CONTROL VALVE Application: SINO TRUCK,FAW,FOTON,JAC TRUCKWe also develop new ...