Vacuum Sensing Valves Automatic and Mechanical Sensing Valves Model No.: ASV18 Valve Part Number d Diameter in. (mm) D1 Top & Bottom Thread L1 Length in. (mm) L2 Length in. (mm) Hex Size in. (mm) Level Compensator Suspensions ASV18 0.16 (4) G 1/8″ 0.26 (6.5) 1.42 (36) 0.51 (13)