Sihi Liquid Ring Vacuum Pump. Model: LPHB 3708. S/N: 2694 313. Capacity: 5 gpm. Max. input horsepower: 5. Max. input rpm: 1150. Vacuum: 28 in. Hg. Airflow: 52 scfm. Sihi pumps offer high vacuum performance with low noise and vibration levels. Sihi pumps offer high vacuum performance with low noise and vibration levels. Great for drying, distillation, deaeration, evisceration, extrusion, vapor recovery, evaporative crystallization, vacuum packaging, and as central vacuum systems. Inlets/outlets: (2) 1-1/2 in. dia. ports with 5 in. dia. flanges, each with (4) 1/2 in. dia. attachment holes at a center-to-center distance of 2-3/4 in. Overall dimensions: 12-1/2 in. L x 9-1/2 in. W x 25 in. H.