Vacuum Sensing Valves Automatic and Mechanical Sensing Valves Model No.: ASV38 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 ASV38 0.16 (4) G 3/8″ 0.47 (12) 1.65 (42) 0.87 (22)