AOLONG TRAILER CONTROL VALVE WITH SILENCER Material: Aluminum Alloy, Zinc Alloy, Nylon Machining: CNC machining ... valve,air dryer,levelling valve and so on2. Strict quality control at ISO 9001:2000 and ISO/TS 16949 3).Good ... : CNC machining centerInspection : 100% leakage test and other test.TRAILER CONTROL VALVE Application: SINO TRUCK,FAW,FOTON,JAC TRUCKWe also develop ...