Sihi Liquid Ring High Performance Vacuum Pump. Model: LPHB 3708. S/N: 3160705. Capacity: 20 in. Hg @ 70 cfm (using dry air). U.S. Motor, 7-1/2 hp, The LPH 3708 liquid ring vacuum pumps are reliable pumps that can be used in a variety of applications; their two stage configuration optimizes performance. The vacuum pumps only moving part is the impeller and shaft assembly. These pumps have no internal metal to metal contacts. Inlets/outlets: (2) 1-1/2 in. dia. ports, each with 5 in. dia. flanges and (4) 1/2 in. dia. thru-holes at center distances of 2-3/4 in. Overall dimensions: 45 in. L x 17 in. W x 20-1/2 in. H.